Entries |
Document | Title | Date |
20080219033 | Switching power supply device - A switching power supply device includes a first series circuit of first and second switching elements connected in parallel with a DC power supply. An isolation transformer has primary and secondary windings and first and second auxiliary windings, a first layer including the primary windings between a second layer of the two auxiliary windings, and a third layer of the secondary windings. A capacitor in series with the primary windings defines a second series circuit in parallel with the second switching element. A rectifying and smoothing circuit includes a rectifying diode and a smoothing capacitor, connected to the secondary windings. First and second control circuits turn on and off the first and second switching elements based on voltages generated in the two auxiliary windings, to obtain a DC output from the rectifying and smoothing circuit, enabling an adequate auxiliary windings voltage and stable switching operation including stable zero-voltage turn-on. | 09-11-2008 |
20080232142 | OUTPUT CURRENT CONTROL CIRCUIT FOR POWER CONVERTER WITH A CHANGEABLE SWITCHING FREQUENCY - A control circuit controls the output current of the power converter at the primary side of the transformer. The control circuit includes a current-detection circuit for generating a primary-current signal in response to the switching current of the transformer. A voltage-detection circuit is coupled to the transformer to generate a period signal and a discharge-time signal in response to the reflected voltage of the transformer. A signal-process circuit is utilized to generate a current signal in response to the primary-current signal, the period signal and the discharge-time signal. The period signal is correlated to the switching period of the switching signal of the power converter. The discharge-time signal is correlated to the duty cycle of switching current at the secondary-side of the transformer. The current signal is correlated to the output current of the power converter. | 09-25-2008 |
20080239767 | Power supply circuit with pulse generating circuit and current-limiting circuit - An exemplary power supply circuit ( | 10-02-2008 |
20080259654 | Compensating for cord resistance to maintain constant voltage at the end of a power converter cord - A cord correction circuit in a primary-side-controlled flyback converter compensates for the loss of output voltage caused by the resistance of the charger cord. In one embodiment, a correction voltage is subtracted from a feedback voltage received from a primary-side auxiliary inductor. A pre-amplifier then compares a reference voltage to the corrected feedback voltage. In another embodiment, the correction voltage is summed with the reference voltage, and the pre-amplifier compares the feedback voltage to the corrected reference voltage. The difference between the voltages on the input leads of the pre-amplifier is used to increase the output voltage to compensate for the voltage lost through the charger cord. The flyback converter also has a comparing circuit and a control loop that maintain the peak level of current flowing through the primary inductor of the converter. Adjusting the frequency and pulse width of an inductor switch signal controls the converter output current. | 10-23-2008 |
20090073727 | Adjusting for conductor loss to regulate constant output voltage in a primary feedback converter - A lower-cost and more precise control methodology of regulating the output voltage of a flyback converter from the primary side is provided, which works accurately in either continuous voltage mode (CCM) and discontinuous mode (DCM), and can be applied to most small, medium and high power applications such cell phone chargers, power management in desktop computers and networking equipment, and, generally, to a wide spectrum of power management applications. Two highly integrated semiconductor chips based on this control methodology are also described that require very few components to build a constant voltage flyback converter. | 03-19-2009 |
20090091953 | Compensating for inductance variation in a power converter using a dual-purpose feedback pin - A comparing circuit and a control loop are used to maintain the peak level of current flowing through an inductor of a flyback converter. An inductor switch control signal controls an inductor switch through which the inductor current flows. The inductor current increases at a ramp-up rate during a ramp time and stops increasing at the end of the ramp time. The comparing circuit generates a timing signal that indicates a target time at which the inductor current would reach a predetermined current limit if the inductor current continued to increase at the ramp-up rate. The control loop then receives the timing signal and compares the target time to the end of the ramp time. The pulse width of the inductor switch control signal is increased when the target time occurs after the end of the ramp time. Adjusting the pulse width controls the peak of the inductor current. | 04-09-2009 |
20090141520 | ISOLATED VOLTAGE CONVERTER WITH FEEDBACK ON THE PRIMARY WINDING, AND CORRESPONDING METHOD FOR CONTROLLING THE OUTPUT VOLTAGE - An embodiment of a voltage converter, designed to convert an input voltage into a regulated output voltage, having: a voltage transformer having a primary winding receiving the input voltage, a secondary winding supplying the output voltage (V | 06-04-2009 |
20090147546 | ISOLATED VOLTAGE CONVERTER WITH FEEDBACK ON THE PRIMARY WINDING AND PASSIVE SNUBBER NETWORK, AND CORRESPONDING CONTROL METHOD - An embodiment of a voltage converter, provided with: a voltage transformer having a primary winding receiving an input voltage, a secondary winding supplying an output voltage, and an auxiliary winding supplying a feedback voltage correlated to the output voltage; a main switch, connected to the primary winding; a control circuit, which controls switching of the main switch and has a sampling stage for sampling and holding the feedback voltage and supplying a sampled signal; and a voltage limiting circuit, provided with a clamp capacitor, designed to be connected across the primary winding. A sampling control stage is connected to the sampling stage, and is designed, during a given operating condition of the voltage converter, to enable updating of the sampled signal on the basis of a state of charge of the clamp capacitor. | 06-11-2009 |
20090147547 | ENERGY TRANSFER DEVICE AND ENERGY TRANSFER CONTROL SEMICONDUCTOR DEVICE - The present invention includes a turn-off signal modulating circuit that periodically varies a turn-off timing of a switching element | 06-11-2009 |
20090175058 | METHOD AND APPARATUS FOR A POWER SUPPLY CONTROLLER RESPONSIVE TO A FEEDFORWARD SIGNAL - An apparatus and method of switching a switch of a power supply in response to an input voltage signal are disclosed. According to aspects of the present invention, a power supply controller includes a switch duty cycle controller coupled to receive a feedback signal and a duty cycle adjust signal. The switch duty cycle controller is coupled to generate a drive signal coupled to control switching of a switch, which is coupled to an energy transfer element, to regulate energy delivered from an input of a power supply to an output of the power supply. The power supply controller also includes a gain selector circuit coupled to receive an input voltage signal, which is representative of an input voltage to the power supply, to generate the duty cycle adjust signal received by the switch duty cycle controller. The maximum duty cycle of the drive signal to be varied in response to a plurality of linear functions over a range of values of the input voltage signal. | 07-09-2009 |
20090303757 | METHOD OF FORMING A POWER SUPPLY CONTROLLER AND STRUCTURE THEREFOR - In one embodiment, a switching controller uses an auxiliary winding voltage of a transformer to form a signal representative of current flow through a secondary winding of the transformer. | 12-10-2009 |
20100008109 | SWITCHING POWER SUPPLY AND SEMICONDUCTOR DEVICE FOR SWITCHING POWER SUPPLY - A switching power supply of the present invention includes: an oscillator circuit for oscillating a signal for turning on a switching element; an error signal generating circuit for generating an error signal having a signal level corresponding to a difference between the signal level of a feedback signal and a reference level; a switching control circuit for turning on the switching element at a time in response to the signal oscillated by the oscillator circuit and turning off the switching element at a time in response to the signal level of the error signal; and a reference level control circuit for controlling the reference level according to a time period during which the switching operation of the switching element is stopped. | 01-14-2010 |
20100027300 | SYSTEMS AND METHODS FOR PRIMARY-SIDE REGULATION IN OFF-LINE SWITCHING-MODE FLYBACK POWER CONVERSION SYSTEM - Switching-mode power conversion system and method thereof. The system includes a primary winding configured to receive an input voltage, and a secondary winding coupled to the primary winding and configured to, with one or more first components, generate, at an output terminal, an output voltage and an output current. Additionally, the system includes an auxiliary winding coupled to the secondary winding and configured to, with one or more second components, generate, at a first terminal, a detected voltage. Moreover, the system includes an error amplifier configured to receive the detected voltage and a first reference voltage and generate an amplified voltage based on at least information associated with a difference between the detected voltage and the first reference voltage. Also, the system includes a compensation component configured to receive the amplified voltage and generate a second reference voltage based on at least information associated with the amplified voltage. | 02-04-2010 |
20100054000 | Accurate voltage regulation of a primary-side regulation power supply in continuous conduction mode operation - A power converter operates in continuous conduction mode and outputs a regulated output voltage. A feedback-derived signal is used to regulate the output voltage. The feedback-derived signal is sampled at multiple time points during an OFF cycle of a power switch. A current-sense signal is also sampled at one or more time points during an ON cycle of the power switch. The current-sense signal is indicative of an output inductor current of the power converter. A calibrated feedback-derived voltage is then generated based on the multiple voltage samples of the feedback-derived signal and the one or more voltage samples of the current-sense signal. The calibrated feedback-derived voltage is less sensitive to an output inductor current loop resistance than the original voltage samples of the feedback-derived signal. The calibrated feedback-derived voltage also compensates for the nonlinearity of a diode of the output inductor current loop. | 03-04-2010 |
20100085780 | Switching power supply circuit - In a RCC type switching power supply circuit, a sensing coil connected magnetically closely with an output coil is equipped in a fly-back transformer. The sensing coil is connected with a timing condenser through a Zener diode and an alternate current voltage output from the sensing coil is rectified and smoothed. Then, the difference between a detection voltage detected as a direct current voltage of the secondary side and the basic voltage of the Zener diode is supplied to the timing condenser to change the discharge/charge time and then change the timing of the switching of a first switching element in order to control the switching time of the first switching element. At the same time, applying the voltage which results from rectifying and smoothing the output voltage from the sensing coil, the charge and discharge of the timing condenser at the non-loading time is controlled in order to prolong the cycle of the switching oscillation and consequently, reduce the power loss. | 04-08-2010 |
20100085781 | ENERGY TRANSMISSION DEVICE AND SEMICONDUCTOR DEVICE FOR ENERGY TRANSMISSION CONTROL - The present invention includes a voltage clamping circuit | 04-08-2010 |
20100110734 | CIRCUIT FOR OUTPUT CURRENT DETECT, CIRCUIT FOR OUTPUT CURRENT FEEDBACK, AND SMPS WHICH LIMITS OUTPUT CURRENT BY PRIMARY SIDE FEEDBACK - A discontinuous mode flyback converter for limiting output current using primary feedback is disclosed. A transformer stores magnetic energy using field current and transfers the magnetic energy using a primary winding and a secondary winding closely coupled to the primary winding. A switching element is coupled to one end of the primary winding of the transformer and controls the current of the primary winding of the transformer. A control unit controls the switching element. A voltage error feedback unit feeds back the error of the output voltage of the transformer to the control unit, thereby regulating the output voltage. An output current feedback circuit detects the flyback period of the transformer, detects the output current information of the transformer from the rate of a flyback period in a cycle, and feeds it back to the control unit, thereby limiting the output current of the transformer. | 05-06-2010 |
20100124081 | SWITCHING POWER SUPPLY - According to the present invention, when a secondary current on period T | 05-20-2010 |
20100128501 | SYSTEMS AND METHODS FOR CONSTANT VOLTAGE MODE AND CONSTANT CURRENT MODE IN FLYBACK POWER CONVERTER WITH PRIMARY-SIDE SENSING AND REGULATION - System and method for regulating a power converter. The system includes a first signal generator configured to receive at least an input signal and generate at least a first output signal associated with demagnetization and a second output signal associated with sampling. Additionally, the system includes a sampling component configured to receive at least the input signal and the second output signal, sample the input signal based on at least information associated with the second output signal, and generate at least a third output signal associated with one or more sampled magnitudes. Moreover, the system includes an error amplifier configured to receive at least the third output signal and a first threshold voltage and generate at least a fourth output signal with a capacitor, the capacitor being coupled to the error amplifier. | 05-27-2010 |
20100142232 | FLYBACK SWITCHING POWER SUPPLY AND CONTROL METHOD THEREOF - A flyback switching power supply capable of regulating an operation frequency based on a current regulation mechanism is disclosed. The flyback switching power supply includes a transformer, a switch, a switch control circuit, and a regulation circuit. The transformer includes a primary winding for receiving an input voltage, a secondary winding for generating an output voltage, and an auxiliary winding. The switch is serially connected to the primary winding for controlling a current flowing through the primary winding. The switch control circuit has a frequency control port and functions to work around an operation frequency for controlling the switch. The operation frequency is under control by a frequency setting current flowing through the frequency control port. The regulation circuit is electrically coupled between the auxiliary winding and the frequency control port. The regulation circuit adjusts the frequency setting current based on an induced current generated by the auxiliary winding. | 06-10-2010 |
20100157630 | FLYBACK POWER SUPPLY WITH FORCED PRIMARY REGULATION - A flyback converter with forced primary regulation is disclosed. An example flyback converter includes a coupled inductor including a first winding, a second winding, and a third winding. The first winding is coupled to an input voltage and the second winding is coupled to an output of the power converter. A switched element is coupled to the second winding. A secondary control circuit is coupled to the switched element and the second winding. The secondary control circuit is coupled to switch the switched element in response to a difference between a desired output value and an actual output value to force a current in the third winding that is representative of the difference between the desired output value and the actual output value. A primary switch is coupled to the first winding. A primary control circuit is coupled to the primary switch and the third winding. The primary control circuit is coupled to switch the primary switch to regulate the output of the power converter in response to the forced current. | 06-24-2010 |
20100165672 | VALLEY-MODE SWITCHING SCHEMES FOR SWITCHING POWER CONVERTERS - An improved valley-mode switching (VMS) scheme and circuitry for implementing the improved VMS switching scheme in a switch-mode power converter are disclosed. For a given switching cycle, a desired switch turn-on time is determined based on a pulse width modulation, pulse frequency modulation, or other suitable power converter control scheme. Also, one or more times corresponding to local minimums (valleys) are predicted for the voltage across a power switch of the switching power converter. The power switch is turned on at a valley immediately subsequent or otherwise subsequent to the desired switch time determined according to the power converter control scheme. Thus, the improved VMS scheme enables low-voltage switch operation to reduce switching loss and EMI noise without restricting the control scheme of the power converter. | 07-01-2010 |
20100238689 | METHOD AND APPARATUS FOR CONTROLLING A CONSTANT CURRENT OUTPUT IN A SWITCHING MODE POWER SUPPLY - A controller for providing a constant output current control signal in a switched mode power supply (SMPS) includes a conduction time compensation circuit that is configured to produce a compensated conduction time interval signal that includes compensation for a ringing waveform of a feedback signal. The compensated signal reflects more accurately the actual conductive time of a rectifying diode in a secondary winding of the switched mode power supply. In one embodiment, the compensated conduction time interval signal is used to generate a fixed ratio between the conduction time and the non-conduction time of the rectifying diode. In another embodiment, the controller also provides a constant voltage control signal. | 09-23-2010 |
20110051471 | COMPACT INVERTER PLUG FOR LED LIGHT STRINGS - Disclosed is a compact inverter plug that can be used with LED lighting strings. The inverter plug has a size and shape that is comparable to a standard wall plug and is capable of plugging into a standard wall socket. The inverter plug is waterproof and can be easily assembled. A unique inverter circuit is utilized that is compact and highly efficient. Monitoring is performed by a transformer coil that generates a monitoring signal. The inverter is controlled by controlling the modulation frequency of a direct current signal using a controller. | 03-03-2011 |
20110122659 | POWER TRANSISTOR DRIVING CIRCUITS AND METHODS FOR SWITCHING MODE POWER SUPPLIES - A power supply controller is provided for providing a drive current to a control terminal of a power transistor in three time intervals. The controller includes control circuits configured to control the drive current in multiple stages. During a first time interval, first drive current includes a current spike for turning on the power transistor in response to a start of the control signal pulse. During a second time interval, a second drive current includes a ramping current substantially proportional to a magnitude of a current through the power transistor. During a third time interval, current flow to the power transistor is at least partially turned off before an end of the control signal pulse. | 05-26-2011 |
20110228571 | Primary Side Current Controller and Related Power Supply - A primary side current controller for a power supply is disclosed. The primary side current controller includes a waveform detection unit, a calculation unit, and a switching controller. The waveform detection unit is used for detecting a waveform signal of the power supply and generating a captured signal. The calculation unit is coupled to the waveform detection unit and used for generating a selected voltage according to the captured signal and a feedback signal of the power supply. The switching controller is coupled to the calculation unit and used for generating a modulation signal according to the selected voltage and the feedback signal. | 09-22-2011 |
20110255312 | POWER CONVERTER WITH PRIMARY-SIDE FEEDBACK CONTROL - A power converter with primary-side feedback control includes a transformer comprising a primary winding, an auxiliary winding, and a secondary winding, for transforming an input voltage into an output voltage; a transistor coupled to the primary winding for controlling electric energy transforming of the transformer according to a first control signal; a control unit coupled to the transistor for generating the first control signal according to a feedback signal in order to control the transistor to be turned on or off; and a peak detection unit coupled between the auxiliary winding and the control unit for generating the feedback signal according to a knee voltage of a first voltage signal. | 10-20-2011 |
20120163041 | METHOD AND APPARATUS FOR A POWER SUPPLY CONTROLLER RESPONSIVE TO A FEEDFORWARD SIGNAL - An example power supply controller includes a switch duty cycle controller coupled to receive a feedback signal and a duty cycle adjust signal. The switch duty cycle controller is coupled to generate a drive signal coupled to control switching of a switch, which is coupled to an energy transfer element, to regulate energy delivered from an input of a power supply to an output of the power supply. The power supply controller also includes a gain selector circuit coupled to receive an input voltage signal, which is representative of an input voltage to the power supply, to generate the duty cycle adjust signal received by the switch duty cycle controller. The duty cycle of the drive signal to be varied in response to a plurality of linear functions over a range of values of the input voltage signal. | 06-28-2012 |
20120287682 | SWITCH MODE POWER SUPPLY AND CONTROL METHOD THEREOF - In one embodiment, a switch mode power supply comprising a switch and a control circuit is disclosed. The control circuit may comprise a multi-function pin configured to receive a first current sampling signal and a first voltage sampling signal. A first comparing signal may be provided by comparing the first voltage sampling signal with a first threshold signal when the switch is turned OFF, and a second comparing signal may be provided by comparing the first current sampling signal with a second threshold signal when the switch is turned ON. The control circuit may be configured to control the switch in accordance with the first comparing signal and the second comparing signal. | 11-15-2012 |
20120300507 | SYSTEMS AND METHODS FOR REDUCING EMI IN SWITCH MODE CONVERTER SYSTEMS - Switch mode power converter system and method thereof. The system includes one or more isolation boxes including at least a first isolation box, an input primary winding for receiving an input signal for the switch mode power converter system, and an output secondary winding for generating an output signal for the switch mode power converter system. The switch mode power converter system is configured to convert the input signal to the output signal. One of the input primary winding and the output secondary winding is substantially enclosed in the first isolation box, and the other of the input primary winding and the output secondary winding is not enclosed in the first isolation box. The first isolation box is conductively connected to a constant-voltage source. | 11-29-2012 |
20130027989 | SYSTEMS AND METHODS FOR PRIMARY-SIDE REGULATION IN OFF-LINE SWITCHING-MODE FLYBACK POWER CONVERSION SYSTEM - Switching-mode power conversion system and method thereof. The system includes a primary winding configured to receive an input voltage, and a secondary winding coupled to the primary winding and configured to, with one or more first components, generate, at an output terminal, an output voltage and an output current. Additionally, the system includes an auxiliary winding coupled to the secondary winding and configured to, with one or more second components, generate, at a first terminal, a detected voltage. Moreover, the system includes an error amplifier configured to receive the detected voltage and a first reference voltage and generate an amplified voltage based on at least information associated with a difference between the detected voltage and the first reference voltage. Also, the system includes a compensation component configured to receive the amplified voltage and generate a second reference voltage based on at least information associated with the amplified voltage. | 01-31-2013 |
20130077357 | ADAPTIVE BIASING FOR INTEGRATED CIRCUITS - Methods and apparatuses are disclosed for generating an adjustable bias current. The value of the adjustable bias current may be determined based in part on an error signal representative of a difference between an actual output value and a desired output value of a power converter. When the error signal is below a lower threshold voltage, the adjustable bias current may be set to a first value. When the error signal is above an upper threshold voltage, the adjustable bias current may be set to a second, higher value. When the error signal is between the lower threshold voltage and the upper threshold voltage, the adjustable bias current may change linearly with the error signal. | 03-28-2013 |
20130088898 | ZERO STANDBY SWITCHING POWER SUPPLY SOLUTION - A switching mode power supply (SMPS) includes a power transistor coupled to the primary winding of transformer and a resistor coupled between the input power source and a control terminal of the power transistor for triggering a primary current flow through the power transistor for providing startup power. A primary side control circuit is configured to regulate the output of the SMPS. A secondary side control circuit is coupled to the secondary winding and being configured to provide a first electrical signal to the secondary winding when an output voltage of the SMPS is less than a first reference voltage, whereupon an awakening signal is induced in the auxiliary winding and causes the primary side control circuit to provide a turn-on signal to the power transistor. The primary side control circuit is configured to enter a standby mode or a normal operating mode in response to the awakening signal. | 04-11-2013 |
20130094254 | METHODS AND POWER CONTROLLERS FOR PRIMARY SIDE CONTROL - Power controllers and related primary-side control methods are disclosed. A disclosed power controller has a comparator and an ON-triggering controller. The comparator compares a feedback voltage with an over-shot reference voltage. Based on an inductance-coupling effect, the feedback voltage represents a secondary-side voltage of a secondary winding. Coupled to the comparator, the ON-triggering controller operates a power switch at about a first switching frequency when the feedback voltage is lower than the over-shot reference voltage. The ON-triggering controller operates the power switch at about a second switching frequency when the feedback voltage exceeds the over-shot reference voltage. The second switching frequency is less than the first switching frequency. | 04-18-2013 |
20130141946 | SWITCHING POWER SUPPLY DEVICE AND METHOD FOR CONTROL THEREOF - A switching power supply device and method for control thereof, including an input voltage generating unit, a transformer, an output voltage generating unit, a MOS transistor, an output voltage detecting unit, a switching control unit, and a power supply unit. The output voltage detecting unit detects a transformer tertiary winding voltage, compares it with a first reference value, compares the differentiated tertiary winding voltage with a second reference value, and determines the start and end of a detection period based on the two comparisons. The output voltage detecting unit also samples and holds the voltage with two sampling pulses within the detection period, selects one of the two sampled and held voltages, and outputs the selected voltage when the detection period ends. | 06-06-2013 |
20130141947 | SWITCHING POWER SUPPLY - A flyback type switching power supply includes between P and N of a direct current output a sudden load change detector circuit, which normally has no power consumption, that detects only a transient fluctuation of a direct current output voltage, and starts the switching of a primary side semiconductor switch when there is no load or a light load, even when the semiconductor switch is in an off state, thereby enabling the detection of the direct current output voltage in a tertiary winding, and suppressing a drop in the direct current output voltage. | 06-06-2013 |
20130141948 | METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE WITH OUTPUT RESET IN A POWER CONVERTER - A control circuit includes a feedback circuit, a drive signal generator, an unregulated dormant mode and output reset control circuit, and a counter. The feedback circuit generates an enable signal and in response, the drive signal generator regulates the output of the power converter. The unregulated dormant mode and output reset control circuit powers down the drive signal generator such that the regulation is ceased when the energy requirement at the output has fallen below a threshold. The drive signal generator is then powered up after a first period of time such that the regulation resumes. The counter then counts cycles of a clock signal for which the enable signal indicates an increase in the energy requirement at the output. The counter disables the drive signal generator when a count of the counter reaches a threshold number to discharge the output to less than a regulation output voltage value. | 06-06-2013 |
20130148387 | CONTROL CIRCUIT AND SYSTEM FOR SWITCH MODE POWER SUPPLY - A switch-mode power supply (SMPS) includes a transformer having a primary winding coupled to a power switch, a secondary winding for providing an output of the power supply, and a controller. The controller includes a first input terminal for receiving a current sensing signal related to a current in the primary winding, a second input terminal for receiving a feedback signal related to a current in the secondary winding, and an output terminal for providing a control signal to turn on and off the power switch. When the feedback signal is higher than a first reference voltage, the controller is configured to cause the SMPS to maintain a constant output current at a first current magnitude. When the feedback signal is lower than the first reference voltage, the controller is configured to cause the SMPS to provide a second output current at a second current magnitude higher than the first current magnitude. | 06-13-2013 |
20130155728 | Isolation of Secondary Transformer Winding Current During Auxiliary Power Supply Generation - An electronic system and method include a controller to actively control power transfer from a primary winding of a switching power converter to an auxiliary-winding of an auxiliary power supply. The switching power converter is controlled and configured such that during transfer of power to the auxiliary-winding, the switching power converter does not transfer charge to one or more secondary-windings of the switching power converter. Thus, the switching power converter isolates one or more secondary transformer winding currents from an auxiliary-winding current. By isolating the charge delivered to the one or more secondary-windings from charge delivered to the auxiliary-winding, the controller can accurately determine an amount of charge delivered to the secondary-windings and, thus, to a load. | 06-20-2013 |
20130223107 | SYSTEMS AND METHODS FOR PROTECTING POWER CONVERSION SYSTEMS BASED ON AT LEAST FEEDBACK SIGNALS - System and method for protecting a power conversion system. An example system controller includes a protection component and a driving component. The protection component is configured to receive a demagnetization signal generated based on at least information associated with a feedback signal of the power conversion system, process information associated with the demagnetization signal and a detected voltage generated based on at least information associated with the feedback signal, and generate a protection signal based on at least information associated with the detected voltage and the demagnetization signal. The driving component is configured to receive the protection signal and output a driving signal to a switch configured to affect a primary current flowing through a primary winding of the power conversion system. The detected voltage is related to an output voltage of the power conversion system. The demagnetization signal is related to a demagnetization period of the power conversion system. | 08-29-2013 |
20130250628 | SAMPLING CIRCUIT FOR MEASURING THE REFLECTED VOLTAGE OF TRANSFORMER FOR POWER CONVERTER - A sampling circuit of the power converter according to the present invention comprises an amplifier circuit receiving a reflected voltage for generating a first signal. A first switch and a first capacitor are utilized to generate a second signal in response to the reflected voltage. A sample-signal circuit generates a sample signal in response to a falling edge of a switching signal. The switching signal is generated in accordance with a feedback signal for regulating an output of the power converter. The feedback signal is generated in accordance with the second signal. The sample signal is utilized to control the first switch for sampling the reflected voltage. The sample signal is disabled once the first signal is lower than the second signal. The sampling circuit precisely samples the reflected voltage of the transformer of the power converter for regulating the output of the power converter. | 09-26-2013 |
20130294118 | Output Current Estimation for an Isolated Flyback Converter With Variable Switching Frequency Control and Duty Cycle Adjustment for Both PWM and PFM Modes - A fly-back power converter has a current-estimating control loop that senses the primary output current in a transformer to control the secondary output. A primary-side control circuit switches primary current through the transformer on and off. A discharge time when a secondary current through an auxiliary winding of the transformer is flowing is generated by sampling a voltage divider on an auxiliary loop for a knee-point. A normalized duty cycle is calculated by multiplying the discharge time by a current that is proportional to the switching frequency and comparing to a sawtooth signal having the switching frequency. The peak of a primary-side voltage is sensed from the primary current loop and converted to a current and multiplied by the normalized duty cycle to generate an estimated current. An error amp compares the estimated current to a reference to adjust the oscillator frequency and peak current to control primary switching. | 11-07-2013 |
20130308350 | SYSTEMS AND METHODS FOR CONSTANT VOLTAGE MODE AND CONSTANT CURRENT MODE IN FLYBACK POWER CONVERTERS WITH PRIMARY-SIDE SENSING AND REGULATION - System and method for regulating a power converter. The system includes a first signal generator configured to receive at least an input signal and generate at least a first output signal associated with demagnetization and a second output signal associated with sampling. Additionally, the system includes a sampling component configured to receive at least the input signal and the second output signal, sample the input signal based on at least information associated with the second output signal, and generate at least a third output signal associated with one or more sampled magnitudes. Moreover, the system includes an error amplifier configured to receive at least the third output signal and a first threshold voltage and generate at least a fourth output signal with a capacitor, the capacitor being coupled to the error amplifier. | 11-21-2013 |
20130329469 | POWER SUPPLY APPARATUS AND IMAGE FORMING APPARATUS - The power supply apparatus includes the feedback winding of a transformer having a first winding, and a second winding whose number of turns is larger than that of the first winding. A voltage output from the transformer is detected. Based on the detected voltage, connection between a switch element and the first winding or the second winding is switched. | 12-12-2013 |
20140003098 | PWM CONTROL CIRCUIT FOR DC-DC CONVERTER, FLYBACK CONVERTER, AND METHOD OF CONTROLLING PWM OF DC-DC CONVERTER | 01-02-2014 |
20140016375 | CIRCUITS AND METHODS FOR INCREASING OUTPUT OF SWITCH MODE POWER SUPPLY - A switching mode power supply (SMPS) includes a transformer having a primary winding for coupling to an input power source, a secondary winding for providing an output voltage of the SMPS, and an auxiliary winding. The SMPS also has a power transistor coupled to the primary winding and a primary side control circuit coupled to the auxiliary winding and the power transistor. The primary side control circuit is configured to regulate the output of the SMPS by controlling the power switch in response to a feedback voltage signal that is representative of an output of the SMPS. The SMPs also has a secondary-side control circuit coupled to the secondary winding and being configured to cause the output voltage of the SMPS to discharge when the output voltage of the SMPS is higher than a first reference voltage. | 01-16-2014 |
20140043868 | SWITCHING POWER SUPPLY SYSTEM AND CONTROL CIRCUIT OF THE SWITCHING POWER SUPPLY SYSTEM - A switching power supply system includes a transformer having a primary winding, a secondary winding and a tertiary winding, a switching device inputted to the primary winding carrying out switching operation on the basis of a first control signal or a second control signal, an output voltage producing section rectifying and smoothing a voltage generated in the secondary winding to produce an output voltage, an output voltage detecting section producing an output voltage detection signal based on a voltage generated in the tertiary winding, a checking pulse generator generating pulses of the first control signal, and a switching controlling section producing the second control signal on the basis of the output voltage detection signal. The switching power supply system is capable of carrying out stable control of the output voltage on the secondary winding side of the transformer with a low power loss. | 02-13-2014 |
20140043869 | POWER SUPPLY APPARATUS AND IMAGE FORMING APPARATUS - The power supply apparatus includes a switch element for turning ON and OFF supply of electric power to a primary winding of a transformer; a determining unit connected to an auxiliary winding of the transformer, for determining an ON-time of the switch element; and a switching unit for switching the ON-time determined by the determining unit. | 02-13-2014 |
20140078790 | SYSTEMS AND METHODS FOR VOLTAGE CONTROL AND CURRENT CONTROL OF POWER CONVERSION SYSTEMS WITH MULTIPLE OPERATION MODES - System and method for regulating a power conversion system. A system controller for regulating a power conversion system includes an operation-mode-selection component and a driving component. The operation-mode-selection component is configured to receive a first signal related to an output load of the power conversion system and a second signal related to an input signal received by the power conversion system and output a mode-selection signal based on at least information associated with the first signal and the second signal. The driving component is configured to receive the mode-selection signal and generate a drive signal based on at least information associated with the mode-selection signal, the driving signal corresponding to a switching frequency. | 03-20-2014 |
20140133194 | APPARATUS AND METHOD FOR DETECTING A CHANGE IN OUTPUT VOLTAGE OF AN ISOLATED POWER CONVERTER - A power converter controller includes a drive circuit coupled to control switching of a power switch to control a transfer of energy from an input of the power converter to an output of the power converter. A voltage sensor is coupled to the drive circuit to receive a feedback signal. The voltage sensor includes pulse sampler circuitry coupled to sample a first voltage representative of one of the peaks other than a first peak of ringing of the feedback signal in a first enabled switching cycle, sample a second voltage representative of the same peak of ringing of the feedback signal in a subsequent enabled switching cycle, and compare the sample of the first voltage with the sample of the second voltage and output a change signal based on the comparison. The drive circuit is further coupled to control switching of the power switch in response to the change signal. | 05-15-2014 |
20140133195 | CONTROL METHOD AND DEVICE FOR SWITCHING POWER SUPPLIES HAVING MORE THAN ONE CONTROL MODE - A control device for controlling a switching power supply adapted to convert an input voltage into an output voltage according to a switching rate of a switching element. The control device includes first control means for switching the switching element in a first working mode at a constant frequency and second control means for switching the switching element in a second working mode at a variable frequency, under a maximum frequency, in response to the detection of a predefined operative condition of the switching power supply. The control device further includes means for selecting the first working mode or the second working mode. | 05-15-2014 |
20140146579 | TRANSISTOR GATE DRIVER WITH CHARGE PUMP CIRCUIT FOR OFFLINE POWER CONVERTERS - A controller of the power converter according to the present invention comprises a gate driver. The gate driver generates a gate-drive signal. The gate-drive signal is coupled to drive a power transistor to switch a transformer of the power converter for regulating an output of the power converter. The gate driver has a charge-pump circuit for charging pump a voltage level of the gate-drive signal. Therefore, the gate-drive signal can fully turn on the power transistor. | 05-29-2014 |
20140160809 | SYSTEMS AND METHODS FOR PEAK CURRENT ADJUSTMENTS IN POWER CONVERSION SYSTEMS - System and method for regulating an output of a power conversion system. An example system controller includes a signal generator and a modulation and drive component. The signal generator is configured to receive at least a first signal indicating a magnitude of an input voltage received by a primary winding of a power conversion system and receive a second signal indicating a magnitude of a primary current flowing through the primary winding, and generate a third signal. The modulation and drive component is configured to receive at least the third signal, generate a drive signal based on at least information associated with the third signal, and output the drive signal to a switch to affect the primary current. | 06-12-2014 |
20140185336 | Switching Power Supply Apparatus and Method of Controlling Switching Power Supply Apparatus - A switching power supply apparatus includes a transformer having a primary winding, a secondary winding, and an auxiliary winding, a switching element coupled in series to the primary winding; an output circuit section generating a voltage output from power transferred from the primary winding to the secondary winding in response to a switching operation of the switching element, a feedback signal generation circuit section configured to, during a secondary side conduction period in which an electric current flows through the secondary winding, generate a feedback signal having a signal level corrected based on a length of the secondary side conduction period, from an auxiliary winding voltage induced in the auxiliary winding, and a control circuit section driving the switching element based on the feedback signal. | 07-03-2014 |
20140211518 | LOW TOTAL HARMONIC DISTORTION AND HIGH POWER FACTOR CORRECTION POWER CONVERTERS - A controller circuit for the control of a power converter is disclosed. An example controller circuit generates a waveform that drives a switch that controls the power converter. The controller circuit includes a divider module that generates a modification factor based on a ratio of the two input signals of the module. The circuit includes a module that generates a first waveform configured for a critical conducting mode of operation of a power converter and an on-time adjuster module that modifies the first waveform based on the modification factor and generates a second waveform. The second waveform is delivered to the switch. An example modification factor is the ratio of the output voltage to the rectified input voltage of the power converter. | 07-31-2014 |
20140218978 | CONVERTER WITH GALVANIC ISOLATION - A converter is suggested comprising a transformer providing a galvanic isolation between a primary side and a secondary side of the converter; at least one switching element; a converter control unit comprising a first pin for controlling the at least one switching element and a second pin for detecting a current signal in the at least one switching element during a first phase; and for detecting an output voltage signal of the secondary side of the converter and an information regarding a current in a secondary winding of the transformer during a second phase. | 08-07-2014 |
20140233273 | SWITCHING POWER SOURCE DEVICE AND CONTROL IC WHICH ARE CAPABLE OF PERFORMING CONSTANT POWER CONTROL - The present invention is a switching power source device which converts AC power of an AC power source into DC power and outputs the DC power, the device including: a rectifying-smoothing circuit configured to output a rectified-smoothed voltage signal obtained by rectifying and smoothing an AC voltage of the AC power source; a transformer having a primary winding, a secondary winding, and an auxiliary winding; a switching element connected to the primary winding of the transformer; and a control circuit configured to turn the switching element on and off based on a voltage signal which is based on an average value of current flowing through the switching element and the rectified-smoothed voltage signal from the rectifying-smoothing circuit. | 08-21-2014 |
20140233274 | POWER SUPPLY CONTROLLER WITH MINIMUM-SUM MULTI-CYCLE MODULATION - An example power supply controller includes a signal separator circuit that generates a feedback signal. An error signal generator generates an error signal in response to the feedback signal. A control circuit generates a drive signal in response to the error signal. The drive signal controls switching of a switch. A multi-cycle modulation circuit is included in the control circuit and generates a skip signal in response to a start skip signal, a stop skip signal and a skip mask signal. The skip mask signal is generated in response to the skip signal. The start skip and stop skip signals cause the drive signal to start skipping or stop skipping, respectively, on-time intervals of cycles. The skip mask signal disables the start skip signal from causing the drive signal to start skipping the on-time intervals of cycles. | 08-21-2014 |
20140247628 | METHOD AND APPARATUS FOR POWER CONVERTER FAULT CONDITION DETECTION - A controller includes a control, a sensor, and a fault detector. The control is configured to control a switch to regulate an output of the power converter. The sensor receives a signal from a terminal of the controller that is representative of an input voltage during an ON state of the switch and is representative of an output voltage during an OFF state of the switch. The sensor is configured to sample the signal from the terminal during the ON state to generate a first sample signal and to sample the signal from the terminal during the OFF state to generate a second sample signal. The fault detector detects a fault condition in response to either the first or the second sample signals. The control inhibits the switching of the switch to reduce a power output level of the power converter in response to the fault condition. | 09-04-2014 |
20140268921 | Topology Detection - Driver circuits comprise power converters detecting automatically a topology used by the driver circuits. A controller controls a plurality of different types of power converters in accordance to a corresponding plurality of different operation modes. The controller comprises a measurement pin coupled to a first topology resistor of a first power converter of a type from the plurality of different types. The different types of power converters comprise topology resistors of corresponding different resistor values. The controller senses a voltage at the measurement pin wherein the voltage at the measurement pin is indicative of a voltage drop at the first topology resistor. Furthermore, the controller determines a type of the first power converter based on the sensed voltage, and selects an operation mode for controlling the first power converter. | 09-18-2014 |
20140307486 | CAPACITOR DISCHARGING METHOD AND DISCHARGING CIRCUIT THEREOF - In one embodiment, a method of controlling a capacitor discharge for a switching power supply, can include: (i) generating a first voltage signal from a voltage at an X capacitor that is coupled between input terminals of the switching power supply; (ii) activating a detection signal in response to the first voltage signal being inactive for a duration of a predetermined time interval, where the detection signal being activated indicates a cut-off of the input terminals; and (iii) at least partially discharging the X capacitor after the cut-off and in response to activation of the detection signal. | 10-16-2014 |
20140347895 | Switching Power-Supply Device - A switching power-supply device includes a COMP-voltage comparator circuit that compares a COMP-voltage obtained by performing phase compensation on the feedback signal, with a first threshold voltage which is a threshold value; and an intermittent-oscillation control circuit that, if it is detected by the COMP-voltage comparator circuit that the COMP-voltage is lower than the first threshold voltage, stops the switching operation of the switching device and performs a transition to a first intermittent oscillation operation in which the switching device performs the switching operation every predetermined first period, wherein if a predetermined delay period elapses in a state where the COMP-voltage is lower than the first threshold voltage, the intermittent-oscillation control circuit performs a transition to a second intermittent oscillation operation in which the switching device performs the switching operation every second period which is an integral multiple of the first period. | 11-27-2014 |
20140355316 | CONTROL DEVICE FOR USE WITH SWITCHING CONVERTERS - The present application provides a control device for controlling a switching converting module to generate an output signal of constant output current from a rectified AC power supply signal. The switching converting module comprises a primary winding for receiving the rectified AC power supply signal and a power switch coupled in series with the primary winding. The control device comprises: an AGC amplifier configured to receive a first sampling signal sampled from the rectified AC power supply signal, and to generate a reference signal of constant amplitude according to the first sampling signal; a signal comparator configured to compare the reference signal with a current sensing signal in proportion to a primary side current flowing through the primary side winding to generate a comparison signal; a signal generator configured to receive a second sampling signal sampled from the output signal, and to generate a clock signal according to the second sampling signal; and a control logic configured to generate a control signal for switching the power switch according to the comparison signal and the clock signal. | 12-04-2014 |
20140362612 | SWITCHING POWER CONVERTER WITH PRIMARY-SIDE DYNAMIC LOAD DETECTION AND PRIMARY-SIDE FEEDBACK AND CONTROL - A switching power converter provides regulated voltage to a load. The switching power converter comprises a transformer including a first primary winding coupled to an input voltage, a second primary winding, a secondary winding coupled to an output of the switching power converter, and an auxiliary winding, a first switch coupled to the first primary winding, and a second switch coupled to the secondary primary winding. A controller generates a first control signal to turn the first switch on or off at a first switching frequency, and a second control signal to turn the second switch on or off at a second switching frequency that is higher than the first frequency. During off cycles of the switches, feedback voltage representing the output voltage of the power converter is generated across the auxiliary winding. The controller controls switching of the first switch to regulate the output voltage based on the feedback. | 12-11-2014 |
20140362613 | LC SNUBBER CIRCUIT - The present disclosure relates to an LC snubber circuit for a switching converter, wherein the switching converter includes an inductor and a switching device connected in series. The LC snubber circuit can include a first snubber diode, a snubber capacitor, a second snubber diode, and a snubber transformer having a primary winding and a secondary winding. The secondary winding of the snubber transformer is connected to an output of the switching converter. | 12-11-2014 |
20140376280 | PRECISE OUTPUT POWER DETECTION - A switching power converter provides regulated output power to a load. The switching power converter comprises a transformer including a primary winding coupled to an input voltage, a secondary winding coupled to an output of the switching power converter, an auxiliary winding on a primary side of the transformer, and a switch coupled to the primary winding of the transformer. Output voltage across the secondary winding is reflected as a feedback voltage across the auxiliary winding. The switching power converter detects output current based on a reset time of the transformer. Based on the detected output power, the switching power converter controls switching of the switch to provide regulated output power. | 12-25-2014 |
20150009720 | METHOD AND APPARATUS FOR CONTROLLING THE MAXIMUM OUTPUT POWER OF A POWER CONVERTER - An example control circuit for use in a power converter includes an input voltage sensor, a current sensor, and a drive signal generator. The input voltage sensor generates a first signal representative of an input voltage (Vin) of the power converter. The current sensor generates a second signal representative of a switch current through a power switch of the power converter. The drive signal generator generates a drive signal to control switching of the power switch in response to the first and second signals. The drive signal generator adjusts a duty cycle of the drive signal based on a product K×Vin×t to control a maximum output power of the power converter, where K is a fixed number and t is a time it takes the second signal to change between two values of the switch current when the power switch is in an on state. | 01-08-2015 |
20150023069 | SYSTEMS AND METHODS FOR HIGH PRECISION AND/OR LOW LOSS REGULATION OF OUTPUT CURRENTS OF POWER CONVERSION SYSTEMS - Systems and methods are provided for signal processing. An example error amplifier for processing a reference signal and an input signal associated with a current of a power conversion system includes a first operational amplifier, a second operational amplifier, a first transistor, a second transistor, a current mirror component, a switch, a first resistor and a second resistor. The first operational amplifier includes a first input terminal, a second input terminal and a first output terminal, the first input terminal being configured to receive a reference signal. The first transistor includes a first transistor terminal, a second transistor terminal and a third transistor terminal, the first transistor terminal being configured to receive a first amplified signal from the first output terminal, the third transistor terminal being coupled to the second input terminal. | 01-22-2015 |
20150043252 | SWITCHING MODE POWER SUPPLY AND THE CONTROL METHOD THEREOF - A switching mode power supply, having: a power switch; an energy storage component coupled to the power switch; a current sense resistor configured to generate a current sense signal; a mode select resistor configured to generate a mode select resistor; a ZCD (Zero Cross Detecting) circuit configured to generate a ZCD signal; and a control circuit configured to provide a switch control signal to control the on and off of the power switch, the control circuit having a multi-function pin configured to receive the mode select signal, the current sense signal and the ZCD signal. | 02-12-2015 |
20150055378 | SYSTEMS AND METHODS FOR FLYBACK POWER CONVERTERS WITH SWITCHING FREQUENCY AND PEAK CURRENT ADJUSTMENTS BASED ON CHANGES IN FEEDBACK SIGNALS - System and method for regulating a power converter. The system includes a first comparator configured to receive a first input signal and a second input signal and generate a first comparison signal based on at least information associated with the first input signal and the second input signal, a pulse-width-modulation generator configured to receive at least the first comparison signal and generate a modulation signal based on at least information associated with the first comparison signal, a driver component configured to receive the modulation signal and output a drive signal to a switch to adjust a primary current flowing through a primary winding of the power converter, and a voltage-change-rate detection component configured to sample the feedback signal to generate a first sampled signal for a first modulation period and to sample the feedback signal to generate a second sampled signal for a second modulation period. | 02-26-2015 |
20150062977 | CIRCUIT FOR GENERATING REFERENCE SIGNAL FOR CONTROLLING PEAK CURRENT OF CONVERTER SWITCH, ISOLATED CONVERTER AND METHOD FOR GENERATING REFERENCE SIGNAL FOR CONTROLLING PEAK CURRENT OF CONVERTER SWITCH - Embodiments of the invention provide a method and a circuit for generating a reference signal for controlling a peak current of a converter switch. According to at least one embodiment, the circuit includes a squarer configured to squire an input voltage signal divided from a primary-side supply voltage of an isolated converter, and a duty ratio calculator configured to calculate a duty ratio of energy transfer to a secondary side. The circuit further includes an operator configured to generate and output a reference signal for controlling the peak current of the converter switch from a square signal of the input voltage signal using the duty ratio of energy transfer calculated by the duty ratio calculator. | 03-05-2015 |
20150062978 | CIRCUIT FOR GENERATING REFERENCE SIGNAL FOR CONTROLLING PEAK CURRENT OF CONVERTER SWITCH, ISOLATED CONVERTER AND METHOD FOR GENERATING REFERENCE SIGNAL FOR CONTROLLING PEAK CURRENT OF CONVERTER SWITCH - Embodiments of the invention provide a method and a circuit for generating a reference signal for controlling a peak current of a converter switch. According to at least one embodiment, a dead-zone generator configured to form a dead-zone in an input voltage signal divided from a primary-side supply voltage of an isolated converter, and a duty ratio calculator configured to calculate a duty ratio of energy transfer to a secondary side. The circuit further includes an operator configured to generate and output a reference signal for controlling the peak current of the converter switch from a dead-zone voltage signal having the dead-zone using the duty ratio of energy transfer calculated by the duty ratio calculator. | 03-05-2015 |
20150062979 | CONSTANT VOLTAGE CONSTANT CURRENT CONTROL CIRCUITS AND METHODS WITH IMPROVED LOAD REGULATION - The present invention discloses CVCC circuits and methods with improved load regulation for an SMPS. In one embodiment, the CVCC can include: a voltage feedback circuit to generate an output voltage feedback signal; a current feedback circuit to generate an output current feedback signal; a control signal generating circuit that receives the output voltage feedback signal and the output current feedback signal, and generates a constant voltage/constant current control signal; a first enable signal generating circuit that compares a first reference voltage and the constant voltage/constant current control signal to generate a first enable signal; and a PWM controller that generates a PWM control signal based on the constant voltage/constant current control signal to control a main switch of the flyback SMPS. | 03-05-2015 |
20150062980 | METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE WITH AN EVENT COUNTER IN A POWER CONVERTER - A control circuit for use in a power converter includes a drive signal generator coupled to generate a drive signal to control switching of a switch to regulate an output of the power converter. An event detection circuit is coupled to the drive signal generator to indicate if a switching period of one switching cycle of the drive signal exceeds a threshold switching period. An event counter circuit is coupled to the event detection circuit to render dormant the drive signal generator if the event detection circuit indicates a period of a switching cycle of the drive signal exceeds the threshold switching period for a threshold consecutive number of switching cycles. | 03-05-2015 |
20150070945 | CONTROLLER PROVIDING PROTECTION FUNCTION AND FREQUENCY-REDUCTION FUNCTION USING A SINGLE PIN AND SYSTEM USING SAME - A controller providing protection function and frequency-reduction function for a power conversion application, including: a voltage sense pin; a current source; a switch having a first end coupled to the current source, a second end coupled to the voltage sense pin, and a control end coupled with a control signal; and a sampling unit having a first node coupled to the voltage sense pin, a second node for providing the control signal, a third node for receiving a PWM signal, a fourth node for providing a first sampled voltage for a protection function, and a fifth node for providing a second sampled voltage for a frequency-reduction function. | 03-12-2015 |
20150085536 | INSULATED POWER SUPPLY APPARATUS - Upper arm connection sections and lower arm connection sections are provided in parallel. An upper arm transformer and a power supply are provided in an area opposed to the lower arm connection sections with respect to the upper arm connection sections. A power supply control section is provided in at least one of an area opposed to the upper arm connection sections with respect to the upper arm transformer, and an area which is sandwiched between at least one of the upper and lower connection sections closest to one side of the substrate positioned in a direction in which the upper arm connection sections are arranged, and the one side. The lower arm transformer is provided in an area opposed to the upper arm connection sections with respect to the lower arm connection sections. The lower arm transformer is common to at least two of the lower arm switching elements. | 03-26-2015 |
20150098255 | INSULATION TYPE SWITCHING POWER SOURCE APPARATUS - A power source apparatus comprises: a transformer that insulates a primary system and a secondary system and uses primary/secondary windings to transform an input voltage into an output voltage; a switching control device that is disposed in the primary system to drive the primary winding, and an output monitor device that is disposed in the secondary system to monitor the output voltage. The transformer includes a first auxiliary winding disposed in the primary system and a second auxiliary winding disposed in the secondary system. The output monitor device drives the second auxiliary winding to generate an induced voltage in the first auxiliary winding when the output voltage becomes smaller than a predetermined threshold voltage. The switching control device temporarily stops driving of the first winding upon detecting a light load state and resumes the driving of the first winding upon detecting the induced voltage in the first auxiliary winding. | 04-09-2015 |
20150103568 | GENERATING A CONTROL SIGNAL BASED ON LEADING EDGE DIMMING DETECTION FOR MAINTAINING INPUT CURRENT OF A POWER CONVERTER - A power converter includes an energy transfer element, a power switch, a controller and a leading edge dimming detection circuit. The controller is coupled to control switching of the power switch to regulate the output of the power converter by controlling a transfer of energy through the energy transfer element. The leading edge dimming detection circuit is coupled to generate a control signal in response to detecting leading edge dimming at the input of the power converter. In one aspect, the leading edge dimming detection circuit detects the leading edge dimming and then generates a control signal to engage a compensator which maintains the input current of the power converter to be equal to or greater than a minimum current. In another aspect, the leading edge dimming detection circuit detects and reutilizes the turn-on current spike energy of a leading edge dimmer. | 04-16-2015 |
20150103569 | HIGH EFFICIENT ISOLATED SWITCHING CONVERTER AND CONTROL METHOD THEREOF - An isolated switching converter includes a transformer having a primary winding, a secondary winding and an auxiliary winding, a primary switch coupled to the primary winding, a secondary switch coupled to the secondary winding, and a feedback circuit coupled to the auxiliary winding to generate a feedback signal indicative of the output voltage. Under normal operation, the primary switch is controlled based on the feedback signal and the secondary switch is controlled based on the status of the primary switch. Under light load condition, the secondary switch is controlled based on the output voltage. The secondary switch is turned on to generate a negative secondary current flowing through the secondary winding and turned off when the negative secondary current reaches a secondary current threshold. The primary switch is turned on based on a negative primary current and turned off when the primary current reaches a primary current threshold. | 04-16-2015 |
20150117071 | Switched Mode Power Supply Including a Flyback Converter with Primary Side Control - A method and apparatus for controlling a flyback converter are presented. The flyback converter includes a transformer, a semiconductor switch coupled to a primary winding of the transformer, a current measurement circuit coupled to the semiconductor switch, a diode coupled in series to a secondary winding of the transformer, and a controller. The controller is configured to receive a feedback voltage, a reference signal, and the measured primary current and generate a control signal for the semiconductor switch dependent on the feedback voltage, the reference signal, and the measured primary current. The semiconductor switch switches on and off cyclically in CCM operation. | 04-30-2015 |
20150295499 | SYSTEMS AND METHODS FOR LOAD COMPENSATION WITH PRIMARY-SIDE SENSING AND REGULATION FOR FLYBACK POWER CONVERTERS - System and method for regulating an output voltage of a power conversion system. The system includes a sampling component located on a chip configured to receive an input voltage through a terminal. The sampling component is configured to sample the input voltage and generate a sampled voltage. Additionally, the system includes an error amplifier configured to process information associated with the sampled voltage and a threshold voltage and generate a first output signal, and a first signal generator configured to generate a second output signal and one or more third output signals. Moreover, the system includes a comparator configured to receive the first output signal and the second output signal and generate a comparison signal, and a gate driver directly or indirectly coupled to the comparator and configured to generate a drive signal based on at least information associated with the comparison signal. | 10-15-2015 |
20150302972 | PLANAR TYPE TRANSFORMER AND SWITCHING POWER SUPPLY CIRCUIT - A planar type transformer includes: a multilayer substrate including a primary main winding pattern and a secondary main winding pattern that perform first power transmission, the primary main winding pattern and the secondary main winding pattern being stacked with an insulating layer interposed between the primary main winding pattern and the secondary main winding pattern; and an auxiliary winding that is disposed outside the multilayer substrate and performs second power transmission between the auxiliary winding and the primary main winding pattern or the secondary main winding pattern. | 10-22-2015 |
20150303787 | SYSTEMS AND METHODS FOR REGULATING OUTPUT CURRENTS OF POWER CONVERSION SYSTEMS - Systems and methods are provided for regulating a power conversion system. An example system controller includes a first controller terminal and a second controller terminal. The first controller terminal is configured to receive a first signal associated with an input signal for a primary winding of a power conversation system. The second controller terminal is configured to output a drive signal to a switch to affect a first current flowing through the primary winding of the power conversion system, the drive signal being associated with an on-time period, the switch being closed during the on-time period. The system controller is configured to adjust a duration of the on-time period based on at least information associated with the first signal. | 10-22-2015 |
20150311778 | FLYBACK POWER CONVERTER AND CONTROL CIRCUIT AND CONTROL METHOD THEREOF - The present invention provides a flyback power converter and a control circuit and a control method thereof. The flyback power converter includes: a power stage circuit, a voltage sense circuit, a current sense circuit, and a control circuit. When the flyback power converter operates in a quasi-resonant mode, the control circuit determines a time point of turning OFF a power switch in the power stage circuit according to a current sense signal, a pulse width modulation (PWM) frequency of a PWM signal, and a predetermined threshold, wherein the control circuit adaptively adjusts an ON period of the power switch, or adaptively adjusts an operation bandwidth or an amplifier gain of an error amplifier circuit in a feedback control loop according to the PWM frequency to mitigate an output voltage ripple. | 10-29-2015 |
20150318779 | START-UP CIRCUIT AND POWER DEVICE USING THE SAME - Disclosed herein are a start-up circuit capable of reducing a leakage current to reduce power consumption, and a power device using the same. The start-up circuit includes: a bias unit connected between a first power source and a second power source and allowing a first current to flow from the first power source to the second power source according to a predetermined voltage; a first start unit connected to the bias unit and driving a second current to apply the predetermined voltage to the bias unit, and stopping driving the second current when a voltage received from the second power source reaches a first voltage; and a second start unit connected to the bias unit and driving a third current, the predetermined voltage being applied to the bias unit by the third current, and stopping driving the third current upon receiving a stop signal. | 11-05-2015 |
20150326131 | HIGH POWER-FACTOR CONTROL CIRCUIT AND METHOD FOR SWITCHED MODE POWER SUPPLY - A switch mode power supply (SMPS) system includes a rectifying circuit for coupling to an AC input voltage and a transformer having a primary winding for coupling to the rectifying circuit and a secondary winding coupled to the primary winding. The system also has a power switch coupled to the primary winding and a control circuit coupled to the power switch. The control circuit is configured to control current flow in the primary winding such that an envelope waveform formed by peak points of current pulses is in phase with the magnitude of the AC input voltage. Moreover, the SMPS system is configured to provide a constant average output current. | 11-12-2015 |
20150333638 | CONFIGURABLE POWER CONTROLLER WITH COMBINATION INPUT - Embodiments described herein describe a power supply configured to provide power to an output load via a power supply transformer. The power supply includes a controller configured to operate in a configuration state and an operating state. During the configuration state, the controller receives a configuration signal from a sense circuit coupled to the controller and selects one of a plurality of operating modes from the configuration signal. During the operating state, the controller controls a switch coupled to the transformer based on the selected operating mode and a sense signal received from the sense circuit representative of the power provided to the output load by the power supply. When the switch is closed, current flows from a power source through the transformer, and when the switch is open, current is prevented from flowing from the power source through the transformer. | 11-19-2015 |
20150340954 | SWITCHING POWER SOURCE, METHOD AND CONTROL CHIP FOR CONTROLLING THE SAME - A switching power source includes: a dimmer connected to an alternating current power supply and having a plurality of operating modes; a filtering/rectifying module connected to the dimmer to filter an alternating current output from the dimmer to obtain a filtered alternating current and rectify the filtered alternating current into a direct current; a dimmer switching module connected to the dimmer; a control module connected to the filtering/rectifying module and the dimmer switching module, respectively, and configured to detect a current operating mode of the dimmer when the switching power source is powered on, generate a dimmer control signal according to the current operating mode, and control the dimmer switching module to turn on or off according to the dimmer control signal to control the dimmer to enter an operating mode; and a primary constant current circuit connected to the control module and the filtering and rectifying module. | 11-26-2015 |
20150340955 | Switching Parameter Based Discontinuous Mode-Critical Conduction Mode Transition - An electronic system includes a controller to provide at least dual-mode conduction control of a switching power converter. In at least one embodiment, the controller is capable to control transitions between discontinuous conduction mode (DCM) and critical conduction mode (CRM) of the switching power converter using a measured switching time parameter having a value corresponding with an approximately peak voltage of a time-varying supply voltage supplied to the switching power converter. In at least one embodiment, the controller dynamically compensates for changing parameters of the electronic system by dynamically determining a minimum non-conductive time of the control switch of the switching power converter using the measured switching time parameter value at approximately the peak of the supply voltage of the supply voltage. | 11-26-2015 |
20150340956 | Utilizing Secondary-Side Conduction Time Parameters of a Switching Power Converter to Provide Energy to a Load - A power distribution system includes controller of a switching power converter to control the switching power converter and determine one or more switching power converter control parameters. In at least one embodiment, the switching power converter utilizes a transformer to transfer energy from a primary-side of the transformer to a secondary-side of the transformer. In at least one embodiment, the switching power converter control parameters includes a secondary-side conduction time delay that represents a time delay between when the primary-side ceases conducting a primary-side current and the secondary-side begins to conduct a secondary-side current. In at least one embodiment, determining and accounting for this secondary-side conduction time delay increases the prediction accuracy of the secondary-side current value and accurate delivery of energy to a load when the controller does not directly sense the secondary-side current provided to the load. | 11-26-2015 |
20150340957 | SYSTEMS AND METHODS FOR REGULATING OUTPUT CURRENTS OF POWER CONVERSION SYSTEMS - Systems and methods are provided for regulating a power conversion system. An example system controller includes: a signal generator configured to receive a converted signal and a first compensation signal and generate a second compensation signal based at least in part on the converted signal and the first compensation signal, the converted signal being associated with an input signal for a power conversion system; a modulation component configured to receive the second compensation signal and a ramping signal and generate a modulation signal based at least in part on the second compensation signal and the ramping signal; and a drive component configured to receive the modulation signal and output a drive signal based at least in part on the modulation signal to a switch to affect the first current, the drive signal being associated with an on-time period, the switch being closed during the on-time period. | 11-26-2015 |
20150372602 | VOLTAGE CONVERTING CONTROLLER, VOLTAGE CONVERTING CIRCUIT, AND CONTROL METHOD FOR VOLTAGE CONVERTING - A voltage converting controller, in which when an output current increases from a first current value to a second current value, the voltage converting controller temporarily sets a control frequency to a maximum frequency value; and after a period of time, sets the control frequency to a target control frequency corresponding to the second current value. In addition, when the output current increases from the first current value to the second current value, the voltage converting controller temporarily sets a secondary-side output voltage to an transient output value; and after a period of time, sets a steady state value of the secondary-side output voltage to an output voltage steady state value corresponding to the second current value. | 12-24-2015 |
20160006358 | CONTROL CIRCUIT - A control circuit is adapted for controlling a converter. The converter includes a transformer and a power switch. The control circuit includes a current sensing unit, a current emulating unit, and a control unit. The current sensing unit senses a current flowing through the power switch coupled to a primary winding of the transformer. The current emulating unit determines a propagation delay period according to a voltage transient time of an auxiliary winding of the transformer and a turn-off time of the power switch, and retrieves several sampling times in a conduction period of the power switch according to the propagation delay period. The current emulating unit obtains a peak current and a valley current according to the sampling voltages corresponding to the sampling times. The control unit generates a control signal configured to control the power switch according to the peak current and the valley current. | 01-07-2016 |
20160020700 | CONTROL METHOD AND CONTROL CIRCUIT FOR IMPROVING DYNAMIC RESPONSE OF SWITCHING POWER SUPPLY - A method of controlling an isolated converter can include: (i) sampling and holding an output voltage of the isolated converter during a present switching cycle to generate a reference voltage signal that is proportional to the output voltage; (ii) comparing, in a predetermined time interval before a next switching cycle, the output voltage against the reference voltage signal, and activating a wake-up signal when the output voltage is less than the reference voltage signal, in order to control a voltage at a secondary winding to represent a variation of the output voltage; (iii) detecting a voltage of the primary winding or the secondary winding, and generating a voltage detection signal; and (iv) controlling the power switch according to the voltage detection signal, in order to maintain the output voltage as an expected voltage. | 01-21-2016 |
20160065078 | CONTROLLER WITH LEAKAGE CURRENT PROTECTION OF A DIODE AND OPERATION METHOD THEREOF - A controller with leakage current protection of a diode includes a comparison unit, a reference voltage generation unit, a time out signal generation unit, and a gate signal generation unit, wherein the diode is applied to a secondary side of a power converter. The comparison unit outputs a corresponding selection signal according to a compensation voltage and a threshold. The reference voltage generation unit outputs a corresponding reference voltage range according to the corresponding selection signal. The time out signal generation unit determines a corresponding time out according to the corresponding selection signal, and generates a corresponding time out signal when a voltage corresponding to an auxiliary winding has no peak to cross an upper limit of the corresponding reference voltage range during the corresponding time out. The gate signal generation unit enters the leakage current protection or a quasi-resonant mode according to the corresponding time out signal. | 03-03-2016 |
20160111962 | CONTROLLER SUPPLY TERMINAL BOOSTING - A power conversion device includes a power switch a first main terminal coupled to a higher potential portion, a second main terminal coupled to a lower potential portion, and a tap coupled to the first main terminal to provide a current for charging a supply terminal capacitor. A controller is coupled to a control terminal of the power switch to control switching of the power switch to produce a regulated output. A supply terminal is to be coupled to a supply terminal capacitor to store a charge for supplying power to at least some of the components of the controller. A voltage regulator is coupled to regulate the charge stored and a potential on the supply terminal capacitor. The current for charging the supply terminal capacitor is selectively drawn from the tap of the power switch in response to the supply terminal capacitor being below a threshold. | 04-21-2016 |
20160164397 | ADAPTIVE BJT DRIVER FOR SWITCHING POWER CONVERTER - A flyback converter is provided that includes a base driver for driving a base current into a base of a BJT power switch. The base driver is controlled so as to adaptively vary the base current across at least some of the pulses. | 06-09-2016 |
20160164419 | PROGRAMMING OF A TWO TERMINAL DEVICE - A two-terminal device that is configured to respond to a voltage modulation of an input signal received through the two terminals by triggering an action. The two-terminal device is further configured to verify a result of the triggered action by modulating a current driven through the two termi+6nals. | 06-09-2016 |
20160164420 | ADAPTIVE REFERENCE VOLTAGE FOR SWITCHING POWER CONVERTERS - A switching power converter is provided that detects an activity signal generated in response to load activity using an adaptively-declining threshold. | 06-09-2016 |
20160164421 | REGULATION OF THE POWER SUPPLY VOLTAGE FOR A FLYBACK CONVERTER CONTROLLER - A switching power converter is provided that includes a detector to detect whether a controller power supply voltage has fallen below a threshold voltage during a dormant period in which a power switch is no longer cycling to deliver power to a load. In response to a detection of such a threshold crossing by the detector, a controller powered by the controller power supply voltage is configured to cycle the power switch to replenish the controller power supply voltage. | 06-09-2016 |
20160164422 | MAGNETIC SENSING TECHNIQUE FOR POWER SUPPLY SYSTEMS - One embodiment includes a power supply system including a transformer comprising a primary, secondary, and auxiliary winding that are magnetically coupled. The system also includes a switch stage that generates a current through the primary winding in response to activation of a switch based on a control signal that is generated based on a feedback voltage associated with the auxiliary winding. The current can be induced in the secondary winding. The system also includes an output stage coupled to the secondary winding and that generates an output voltage based on the current induced in the secondary winding. The system further includes a feedback stage coupled to the auxiliary winding and comprising a discriminator configured to determine a zero-current condition associated with the current induced in the auxiliary winding based on monitoring a change in slope of the feedback voltage and to measure the feedback voltage during the zero-current condition. | 06-09-2016 |
20160172964 | FAST STARTUP CONTROL CIRCUIT FOR SWITCH MODE POWER SUPPLY | 06-16-2016 |
20160172985 | INSULATED DC POWER SUPPLY AND A METHOD OF CONTROLLING SAME | 06-16-2016 |
20160190937 | SYSTEMS AND METHODS FOR VOLTAGE REGULATION OF PRIMARY SIDE REGULATED POWER CONVERSION SYSTEMS WITH COMPENSATION MECHANISMS - Systems and methods are provided for voltage regulation of power conversion systems. An example system controller includes: a first sampling component configured to sample a sensing signal and determine a compensation signal based on at least in part on the sensing signal, the sensing signal being associated with a first current flowing through a primary winding of a power conversion system; a signal processing component configured to receive a feedback signal and the compensation signal and generate a first signal based at least in part on the feedback signal and the compensation signal, the feedback signal being associated with an auxiliary winding coupled with a secondary winding of the power conversion system; an error amplifier configured to receive the first signal and a reference signal and generate an amplified signal based at least in part on the first signal and the reference signal. | 06-30-2016 |
20160204706 | CIRCUITS AND METHODS FOR REDUCING OUTPUT VOLTAGE OVERSHOOT OF SWITCH MODE POWER SUPPLY | 07-14-2016 |
20160254753 | DETECTING OPEN CONNECTION OF AUXILIARY WINDING IN A SWITCHING MODE POWER SUPPLY | 09-01-2016 |