| Entries |
| Document | Title | Date |
|---|
| 20100053998 | SWITCHING POWER SUPPLY DEVICE - A switching power supply device includes: a transformer that has a primary winding and a secondary winding; a switching element connected to the primary winding of the transformer; a control circuit that controls the switching element to be turned on/off in a case where a voltage is inputted to the primary winding of the transformer, and thereby induces a voltage in the secondary winding of the transformer; and a rectifying/smoothing circuit that rectifies and smoothes the voltage induced in the secondary winding of the transformer, and outputs the rectified and smoothed voltage to a load. The control circuit has: a current control unit that controls the switching element to prevent a current flowing through the switching element from being lowered to a fixed value or less in a case where the load is light; and an intermittent control unit that, in the case where the load is light, controls the switching element to perform an intermittent oscillation operation based on a feedback signal corresponding to an output voltage to the load. | 03-04-2010 |
| 20110194309 | METHOD AND APPARATUS TO CONTROL A POWER CONVERTER HAVING A LOW LOOP BANDWIDTH - A power converter controller is disclosed. An example power converter controller includes a feedback sensor circuit coupled to receive a feedback signal representative of an output of the power converter. The controller also includes a feedback sampling signal generator coupled to generate a feedback sampling signal coupled to be received by the feedback sensor circuit. The feedback sensor circuit is coupled to sample the feedback signal in response to the feedback sampling signal. The controller also includes a state machine coupled to the feedback sensor circuit to control switching of a switch of the power converter circuit according to one of a plurality of operating condition states in response to the feedback sensor circuit. The controller also includes a feedback time period signal generator coupled to generate a feedback time period signal coupled to be received by the state machine. A period of a feedback time period signal is substantially greater than a period of the feedback sampling signal. The state machine is coupled to be updated in response to the feedback time period signal. | 08-11-2011 |
| 20100157629 | SEMICONDUCTOR LASER APPARATUS - A switching power supply includes: a blanking period generating circuit for prohibiting a main switching element from being turned on from the time the main switching element is turned on to the time a blanking time elapses; a soft start period generating circuit for generating a soft start period from the start of the oscillation of the main switching element to the lapse of a soft start time; and a blanking time adjusting circuit for generating a signal for shortening the blanking time in the soft start period as compared with after the lapse of the soft start period. | 06-24-2010 |
| 20130077354 | Controller for a Switched Mode Power Supply - A controller ( | 03-28-2013 |
| 20130077355 | 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 coupled to an energy transfer element and an input of the power converter. An output voltage sensor including first and second pulse sampler circuits is coupled to capture first and second peak voltages, respectively, that are representative of a second peak of a ringing voltage of a feedback signal representative of an output of the power converter. The first pulse sampler circuit is coupled to capture the first peak voltage at a first time in the feedback signal. The second pulse sampler circuit is coupled to capture the second peak voltage at a second time in the feedback signal. The drive circuit is coupled to receive a change signal from the output voltage sensor in response to the first and second peak voltages. | 03-28-2013 |
| 20130039097 | POWER CONVERSION APPARATUS - A power conversion apparatus capable of suppressing adverse effects of noise caused by crossing of wiring patterns on a wiring board mounting the apparatus thereon. The apparatus includes a transformer, a switching element connected to the transformer, a feedback rectification circuit, and a control circuit operable to control the switching element in response to a DC voltage from the feedback rectification circuit. A first wiring pattern electrically connecting the feedback rectification circuit and the control circuit is formed in one of two surface regions of the wiring board separated by an imaginary line running through a junction of the first wiring pattern and the feedback rectification circuit and a junction of the first wiring pattern and the control circuit, and a second wiring pattern electrically connecting the control circuit and the switching element is formed outside an area enclosed by the imaginary line and the first wiring pattern. | 02-14-2013 |
| 20080225557 | HIGH VOLTAGE POWER SUPPLY - Provided is a high voltage power supply which includes a controller to provide a PWM signal and a power signal, an input unit to receive the PWM signal provided from the controller, a comparison unit to control output of the power signal supplied from the controller by comparing a signal filtered to a DC voltage by the input unit to a voltage reference signal, a transformation unit to transform the power signal output from the comparison unit, and a rectification unit to rectify the signal output by the transformation unit, wherein the high voltage power supply further includes a power input delay unit to delay the supply of the power signal to the comparison unit by a predetermined time from when the power supplied from the controller for input into the comparison unit. The high voltage power supply can prevent components of a device from being damaged due to sudden voltage surge in an output power output from an output terminal, which can occur when a time at which a PWM signal is transitioned to a HIGH state. The power signal is delayed with respect to a time at which a high voltage driving power 24 [V] is initially supplied. | 09-18-2008 |
| 20080298090 | Digital Constant On-Time Power Supply Control - A switched voltage regulator provides improved regulation at a lower clock rate/sampling frequency (e.g. several orders of magnitude lower than would be required for comparable regulation) while using a low resolution digital pulse width modulator such that limit cycle oscillations occur (and thus of low cost and complexity and small size) by limiting the amplitude of limit cycle oscillations which therefore need not be avoided by more complex arrangements which are not commercially feasible. Limiting of amplitude of limit cycle oscillations is achieved by adding essentially a digitized ripple voltage signal corresponding to the difference between the output of the voltage regulator and an average output of the voltage regulator as an input to the digital pulse width modulator. Performance of this arrangement may be enhanced by adding a ramp signal to the digitized ripple voltage signal and even further enhanced by limiting the ramp signal to a range which corresponds to steady state operation but not transients. | 12-04-2008 |
| 20130027984 | CURRENT-FED ISOLATION CONVERTER - A current-fed isolation converter includes a coil that is connected to a primary side of a transformer, a power source that supplies electric power to the primary side of the transformer, a switching element that controls a first electric current flowing in the coil, a snubber circuit that includes a rectifying element and a capacitive element that is charged by a second electric current flowing in the rectifying element, and a step-down power supply circuit that regenerates electric charge of the capacitive element to the power source. The snubber circuit controls an excess voltage that is generated when the switching element is turned off. The power supply circuit maintains a charging voltage of the capacitive element at a predetermined voltage value. | 01-31-2013 |
| 20130027985 | CONTROL INTEGRATED CIRCUIT OF A SWITCH POWER SUPPLY AND A SWITCH POWER SUPPLY USING THE SAME - A control integrated circuit for controlling a switch power supply, including: a voltage collecting module, configured to collect a feedback voltage based on an output voltage of the switch power supply; an error amplifying module, configured to compare the feedback voltage with a reference voltage and generate an error voltage; a time collecting module, configured to obtain a degaussing time signal based on the feedback voltage; and a constant voltage and current module, configured to collect a peak current feedback signal of a switch transistor, generate a control signal based on the error voltage, the degaussing time signal and the peak current feedback signal, wherein the control signal is for controlling an operating frequency and a duty ratio of the switch transistor, and control the switch transistor according to the control signal. | 01-31-2013 |
| 20130027983 | AC/DC CONVERTER, AND AC POWER ADAPTER AND ELECTRONIC APPARATUS USING THE SAME - The present invention provides an Alternating Current/Direct Current (AC/DC) converter employing measures not only against residual voltage but also to reduce power consumption. The AC/DC converter receives an Alternating Current (AC) voltage through a concentric plug and converts the AC voltage into a Direct Current (DC) voltage. A discharge path is disposed on a path from a discharge terminal to a ground terminal. A detection circuit compares a wave detection voltage with a predetermined threshold voltage, and enables the discharge path to be turned on when the wave detection voltage is continuously lower than the threshold voltage for a predetermined detection time. | 01-31-2013 |
| 20090147544 | MODULATED TRANSFORMER-COUPLED GATE CONTROL SIGNALING METHOD AND APPARATUS - A modulated transformer-coupled gate control signaling method and apparatus provides reduction of circuit complexity and robust design characteristics in switching power circuits having a transformer-coupled gate drive. A modulated control signal at a rate substantially higher than the switching circuit gate control rate is provided from the controller circuit to a demodulator via transformer coupling. Power for the demodulator can be obtained by rectifying the modulated control signal at the demodulator, or from another transformer winding. The modulation scheme is chosen to have a DC average value of zero, eliminating any magnetization current management requirements. The modulated control signal may carry redundant control information and/or may encode additional information to provide a more sophisticated gate drive control, such as oversampled gate control information. | 06-11-2009 |
| 20130070485 | SWITCHING POWER CONVERTER AND CONTROL METHOD THEREOF - A switching power converter with an input terminal configured to receive a first input voltage; an output terminal configured to provide an output current to a load, wherein the output current has a peak value and an average value; a power switch; a first loop coupled to the input terminal, wherein the first loop configured to generate a first output signal based on the first input voltage; a second loop configured to generate a second output signal based on the output current; a multiplier configured to generate a multiplying signal based on multiplying the first output signal with the second output signal; and a driving circuit configured to generate a driving signal based on the multiplying signal to control the power switch, so as to reduce the ratio between the peak value and the average value of the output current. | 03-21-2013 |
| 20130114308 | Switching Regulator and Control Circuit and Control Method Thereof - The present invention discloses a switching regulator and a control circuit and a control method thereof. The control circuit of the switching regulator, which controls rectified power within a predetermined range, detects an input voltage and an input current to generate a voltage detection signal and a current detection signal respectively, and the voltage detection signal and the current detection signal are multiplied by one the other to generate a power index. The control circuit generates an error signal according to the power index and a reference signal. A low-pass-filter filters a high frequency band in the process. A control signal generation circuit of the control circuit generates a control signal according to the error signal. And a driver circuit of the control circuit generates an operation signal according to the control signal, for switching a power switch to convert the rectified power to an output voltage. | 05-09-2013 |
| 20130114307 | SYSTEMS AND METHODS FOR PROTECTING POWER CONVERSION SYSTEMS UNDER OPEN AND/OR SHORT CIRCUIT CONDITIONS - System and method are provided for protecting a power converter. The system includes a first comparator, and an off-time component. The first comparator is configured to receive a sensing signal and a first threshold signal and generate a first comparison signal based on at least information associated with the sensing signal and the first threshold signal, the power converter being associated with a switching frequency and further including a switch configured to affect the primary current. The off-time component is configured to receive the first comparison signal and generate an off-time signal based on at least information associated with the first comparison signal. The off-time component is further configured to, if the first comparison signal indicates the sensing signal to be larger than the first threshold signal in magnitude, generate the off-time signal to keep the switch to be turned off for at least a predetermined period of time. | 05-09-2013 |
| 20130094249 | SECONDARY SIDE SYNCHRONOUS RECTIFICATION CONTROL CIRCUIT AND SWITCHING CONVERTER - A secondary side synchronous rectification control circuit is disclosed. The control circuit includes an inverted amplifier, a first comparator, and a driving unit. The inverted amplifier has an input end for receiving a drain source voltage signal from a synchronous rectification transistor and outputting an inverted amplification signal. The first comparator receives the inverted amplification signal and a first reference voltage for outputting a first comparison signal. The driving unit receives the first comparison signal and generates a driving signal according to the first comparison signal, for controlling the conduction status of the synchronous rectification transistor. The drain source voltage of the synchronous rectification transistor in the present invention is inverted amplified by an inverted amplifier, and it is connected to a comparator for generating the driving signal. The errors and defects of the turn-off timing of the driving signal may be solved and eliminated. | 04-18-2013 |
| 20130100708 | POWER FACTOR IMPROVEMENT CIRCUIT - A power factor improvement circuit includes a low frequency filter unit installed between two electrodes of an output terminal of a rectifier unit for adjusting voltage and current inputted to a PWM control IC in-phase, and first and second compensation circuits installed at a current compensation terminal and a voltage compensation terminal of the PWM control IC respectively, and the first and second compensation circuits are provided for reducing the current gain of the phase adjustment unit to avoid any unnecessary action of the PWM control IC, so as to achieve the effect of controlling a power factor to a level over 0.90 when a full voltage of 90-264V is inputted. | 04-25-2013 |
| 20130114306 | DYNAMIC POWER FACTOR CORRECTION AND DYNAMIC CONTROL FOR CONVERTER IN POWER SUPPLY - A welding or cutting system is provided using an interleaved buck-boost stage which dynamically controls power factor correction and operation of the interleaved buck-boost modules to optimize efficiency and operation of the welding system. | 05-09-2013 |
| 20090010027 | SWITCHING POWER SUPPLY APPARATUS - A switching power supply apparatus which includes a DC power supply, an isolation transformer having primary, secondary and tertiary windings, and a switching element, and in which, by turning the switching element on and off, the high-frequency voltage appearing in the secondary windings of the isolation transformer is rectified to obtain a DC output, power consumption can be decreased during standby (in burst mode) in particular by means of a control circuit which controls the turn-on and turn-off of the element and similar. | 01-08-2009 |
| 20130121035 | ULTRA LOW STANDBY CONSUMPTION IN A HIGH POWER POWER CONVERTER - A power converter includes a dc input having first and second terminals. A main converter is coupled to the first terminal of the dc input. A standby circuit coupled to the second terminal of the dc input and the main converter. The main converter is coupled to control a transfer of energy from the dc input through the standby circuit to a main output of the main converter during a normal operating condition of the power supply. The standby circuit is coupled to decouple the main converter from the second terminal of the dc input during a standby operating condition of the power converter. A standby converter is coupled to the first and second terminals of the dc input to control a transfer of energy from the dc input to a standby output of the standby converter during the standby operating condition of the power converter. | 05-16-2013 |
| 20080239760 | Primary only constant voltage/constant current (CVCC) control in quasi resonant convertor - A power supply apparatus and method of regulating is provided. A converter circuit includes a primary switching element and an auxiliary switching element. The auxiliary switching element is for transferring a reflected voltage signal. A transformer includes a primary and a secondary, the primary is coupled with the converter circuit. The primary and the secondary each comprise a single winding. An output rectifier circuit is coupled with the secondary of the transformer. A resonant circuit is included in the converter circuit and is coupled with the primary. The resonant circuit includes one or more resonance capacitors that are configured for providing a transformer resonance. The transformer resonance comprises the reflected voltage signal, the capacitance of the one or more resonance capacitors and a parasitic capacitance of the transformer. The reflected voltage signal is reflected from the secondary to the primary. A current feedback circuit is coupled between the primary and a controller. A virtual output current feedback loop is provided for regulating an output current using the reflected voltage signal. | 10-02-2008 |
| 20100008106 | SWITCHING CONTROL CIRCUIT, SEMICONDUCTOR DEVICE AND SWITCHING POWER SOURCE APPARATUS - At the starting time and an overload time in which the output voltage of the switching power source apparatus is low, if an overcurrent state, in which the ON period of the switching device becomes short and a current not less than the current limit value of the switching device flows through the switching device, occurs, this overcurrent state is detected. The blanking period of a blanking pulse signal is made shorter than the blanking period that is obtained during steady operation, and the ON period of the switching device is made shorter. Hence, the device current flowing through the switching device can be made small in each pulse for the switching operation, and, at the same time, the device current is suppressed from increasing each time a pulse for the switching operation is generated. | 01-14-2010 |
| 20100124078 | ELECTRONIC DEVICE AND POWER SUPPLY THEREOF - A power supply includes a first convertor, a second convertor, and a transformer. The first convertor generates an alternating current (AC) voltage. The transformer includes a primary winding and a secondary winding. The primary winding is connected to the first convertor and receives the AC voltage. The secondary winding includes a first tap, a second tap, and a third tap disposed between the first tap and the second tap. The second convertor includes a first rectifier circuit connected to the first tap and the second tap, and a second rectifier circuit connected to the third tap. The first rectifier circuit generates a first direct current (DC) voltage. The second rectifier circuit generates a second DC voltage. | 05-20-2010 |
| 20120033450 | MULTIPLE POWER SUPPLIES BALANCE SYSTEM - A multiple power supplies balance system includes a plurality of power supply circuits on a circuit board each having a power output route. Each power supply circuit includes a power supply feedback unit which has a reference level terminal to determine output potential of the power supply circuit. The circuit board also has an output route electrically connected to the power output route to converge current sending to a load. Thus the circuit board contains multiple sets of power supply circuits coupled in parallel. The circuit board also has a proportion distribution circuit to correct output variations of each power supply circuit. The proportion distribution circuit includes a variable impedance element which is electrically connected to the reference level terminals and controllable to proportionally change equivalent impedance connected to each reference level terminal, thus change proportionally output potential of each power supply circuit. | 02-09-2012 |
| 20120294046 | POWER SUPPLY APPARATUS - A second control circuit is configured to switch a pulse signal to a level which turns off a second switching transistor when a coil current that flows through a primary winding reaches a predetermined threshold current. The second control circuit is configured to start a switching operation when a power supply for an electronic device is turned on, to set the threshold current to a first value when an intermediate voltage is higher than a predetermined level, and to set the threshold current to a second value that is lower than the first value when the intermediate voltage is lower than a predetermined level. A first control circuit is configured to start a switching operation upon receiving an instruction from a microcontroller to start operating. | 11-22-2012 |
| 20090190378 | POWER SUPPLY DEVICE OUTPUTTING PULSED ELECTRICAL CURRENT - The power supply device of the present invention which outputs pulsed electrical current includes an inverter which converts an input voltage to high frequency AC, a rectifier which rectifies the output of the inverter and converts it to DC, and an output polarity changeover unit which, via a reactor, alternatingly turns ON and OFF the output at a positive electrode side of the rectifier and the output at a negative electrode side thereof. Moreover, this power supply device includes a current transformer including a closed magnetic circuit or coil, pierced by a first output current line in which the current at the positive electrode flows, and by a second output current line in which the current at the negative electrode flows. The directions of piercing of the output current lines through the current transformer are set so that the directions in the current transformer, in which current flows in the first and second output current lines, are the same. | 07-30-2009 |
| 20120106205 | POWER SUPPLY WITH OPEN-LOOP PROTECTION AND SHORT-CIRCUIT PROTECTION - The power supply according to the present invention comprises a transformer, a power switch, a signal generating circuit, an on-time detection circuit, and a delay circuit. The transformer receives an input voltage and generates an output voltage. The power switch switches the transformer for regulating the output voltage. The signal generating circuit generates a switching signal for controlling switching of the power switch. The on-time detection circuit detects an on-time of the power switch and generates a short-circuit signal. The delay circuit counts to a first delay time or to a second delay time in response to a feedback signal of the power supply and the short-circuit signal to generate a turn off signal for controlling the signal generating circuit to latch the switching signal. | 05-03-2012 |
| 20090290387 | SWITCHING POWER SUPPLY WITH INCREASED EFFICIENCY AT LIGHT LOAD - A switching power supply with the increased efficiency at light load has a switching power circuit, a power monitoring circuit and a light load power supplying circuit. The switching power circuit converts an AC power to a stable DC power and sends the DC power to a load according to voltage variation of the load. When the power monitoring circuit detects the AC power and determines that the load is in a light state, the power monitoring circuit controls the light load power supplying circuit to output a small-power DC to the load. As the DC power provided by the light load power supplying circuit is small, the switching loss ratio is lower in its light load state. Therefore, the operating efficiency at the light load state is higher. | 11-26-2009 |
| 20090168462 | CIRCUIT DEVICE AND METHOD OF PROVIDING FEEDBACK ACROSS AN ISOLATION BARRIER - In an embodiment, a circuit device includes a network interface responsive to a powered network to receive a power supply and data and includes an electrical isolation barrier adapted to define a non-isolated power domain and an isolated power domain. The circuit device further includes a first control circuit associated with the non-isolated power domain. The first control circuit is coupled to a primary winding of a transformer to control current flow via the primary winding. The circuit device also includes a second control circuit associated with the isolated power domain. The second control circuit is coupled to a secondary winding of the transformer and is adapted to detect a power error associated with the secondary winding. The second control circuit transfers a command across the electrical isolation barrier to the first control circuit to adjust a current at the primary winding in response to detecting the power error. | 07-02-2009 |
| 20080316775 | Soft-switching circuit for power supply - A soft-switching circuit for a power supply comprises a bridgeless rectifier circuit and an auxiliary circuit. The auxiliary circuit is connected to the bridgeless rectifier circuit, which comprises at least one filtering inductor, two main switches, two diodes and a capacitor. The filtering inductor is connected to the first diode. The first diode is connected to the second diode. The second diode is connected to the first main switch. The first main switch is connected to the second main switch. The diodes and the main switches are connected in parallel with the capacitor to reduce conducting loss. The auxiliary circuit comprises at least one resonant inductor, an auxiliary switch, at least two diodes and a voltage source circuit. The diodes are connected to the resonant inductor and further connected to the voltage source circuit. The voltage source circuit is connected to the auxiliary switch, whereby the soft-switching circuit can accomplish zero voltage switching and zero current switching to provide low conducting loss and low switching loss. | 12-25-2008 |
| 20100128499 | STEP-DOWN VOLTAGE CONVERTER - A step-down voltage converter ( | 05-27-2010 |
| 20110267843 | METHOD AND APPARATUS TO LIMIT OUTPUT POWER IN A SWITCHING POWER SUPPLY - An example integrated circuit controller for a power supply includes a modulator, a drive signal generator, a comparator, and a variable current limit generator. The modulator generates an enable signal having logic states responsive to a feedback signal. The drive signal generator either enables or skips enabling a switch of the power supply during a switching period in response to the logic state of the enable signal. The comparator asserts an over current signal to disable the switch if current flowing through the switch exceeds a variable current limit. The variable current limit generator sets the variable current limit to a first current limit in response to one logic state of the enable signal during a switching period and sets the variable current limit to a second current limit if the enable signal transitions logic states and the over current signal is asserted during the switching period. | 11-03-2011 |
| 20080278970 | IN-BODY INFORMATION ACQUIRING APPARATUS AND POWER-SUPPLY CIRCUIT - An in-body information acquiring apparatus includes a function executing unit that realizes a predetermined function inside a body of a patient. A power-supply circuit includes a power unit that includes a cell and that outputs a first current and a first voltage; and a converter that converts the first current to a second current, which is a current required to operate the function executing unit for a predetermined time, and converts the first voltage to a second voltage, which is a voltage required to operate the function executing unit. | 11-13-2008 |
| 20080285311 | DC-DC CONVERTER - In a DC-DC converter of the present invention, a converting circuit converts a DC-DC voltage outputted from a DC power supply into an AC voltage, and to output to a series circuit in which a primary winding of a first transformer, a first reactor, and a current resonance capacitor are connected to one another in series. A primary winding of a second transformer, a primary winding of a third transformer, and a second reactor constitute a closed loop. A secondary winding of the second transformer and a secondary winding of the third transformer are connected in series to both ends of a secondary winding of the first transformer. A first rectifying/smoothing circuit rectifies and smoothes a voltage of the secondary winding of the second transformer. A second rectifying/smoothing circuit rectifies and smoothes a voltage of the secondary winding of the third transformer. | 11-20-2008 |
| 20090180302 | SWITCHING POWER SUPPLY APPARATUS AND SEMICONDUCTOR DEVICE USED IN THE SWITCHING POWER SUPPLY APPARATUS - A switching power supply apparatus having a highly accurate overvoltage protection function which is free of erroneous operation is provided. A regulating circuit connected to an auxiliary winding generates an AC voltage proportional to a voltage component in which the ringing component has been removed from the AC voltage induced in the auxiliary winding by the switching operation of a switching element. If the peak value of the AC voltage generated by the regulating circuit is equal to or greater than a prescribed value, an overvoltage detection circuit controls the switching operation of the switching element so as to reduce the output DC voltage. | 07-16-2009 |
| 20090086511 | CONVERTER CIRCUIT WITH PULSE WIDTH FREQUENCY MODULATION AND METHOD THEREOF - A converter circuit is provided herein. In the converter, a voltage converting unit receives an input voltage and outputs an output voltage according to the magnitude of the input voltage by switching operation based on a control clock signal. A comparing circuit generates a power good pulse signal by comparing the output voltage with a reference voltage. A pulse width frequency modulation circuit receives the power good pulse signal and a source clock signal to provide the control clock signal. The pulse width of the source clock signal is varied gradually and the frequency of the source clock signal is also changed during a period that the power good pulse signal remains in the first logic state, and the pulse width frequency modulated source clock signal is output as the control clock signal. | 04-02-2009 |
| 20110228565 | SWITCHMODE POWER SUPPLY FOR DIMMABLE LIGHT EMITTING DIODES - A power supply has a rectifier for producing a supply voltage from an AC source. A transformer includes a primary winding, a secondary winding, and an auxiliary winding, wherein the supply voltage is applied to the primary winding by a first switch. A controller, powered by voltage at a node, pulses the first switch between conductive and non-conductive states. A second rectifier is coupled between the auxiliary winding and the node. A starting resistor applies voltage derived from the supply voltage to the node. A second switch, in series with the starting resistor, is rendered non-conductive by a delay circuit a defined time period after a given voltage occurs at the node. When the power supply initially activates, the starting resistor supplies voltage to the node, soon thereafter voltage is supplied from the secondary winding. When the defined time period elapses, the delay circuit operationally disconnects the starting resistor. | 09-22-2011 |
| 20120127760 | SWITCHING POWER SUPPLY AND ELECTRONIC DEVICE USING THE SAME - A switching power supply includes: transformer 60 which includes a primary winding and a secondary winding and outputs, through the secondary winding, an AC voltage based on the current supplied to the primary winding; switching element 61 which controls current supply to the primary winding; rectifying/smoothing circuit 65 which converts the AC voltage output from the secondary winding into a DC voltage; voltage detecting circuit 62 which detects the DC voltage converted by rectifying/smoothing circuit 65; feedback amplifier 63 which is supplied with the DC voltage detected by voltage detecting circuit 62 as one input and which is supplied with a reference voltage as the other input, so as to output a difference between the input voltage values; and control circuit 64 which controls switching element 61, so as to eliminate the difference detected at feedback amplifier 63. Upon receipt of an instruction signal from the outside, voltage detecting circuit 62 supplies to feedback amplifier 63, a voltage higher than the voltage output before receipt of the instruction signal. | 05-24-2012 |
| 20120195075 | DIRECT CURRENT/DIRECT CURRENT CONVERTER, AND POWER SUPPLY APPARATUS AND ELECTRONIC DEVICE USING THE SAME - A direct current (DC)/DC converter capable of lowering power consumption and capable of being started in a short time is provided. A voltage generated at a second output capacitor is input to a power supply terminal. An input voltage is input to a high voltage terminal. A charging transistor is a N-channel Metal Oxide Semiconductor Field Effect Transistor disposed between the high voltage terminal and the power supply terminal and applied with a bias so that the charging transistor is normally on. In a first state, in which the voltage of the power supply terminal is lower than a specified first threshold voltage, a current limiting circuit limits a charging current flowing from the high voltage terminal to the power supply terminal, and in a second state in which the voltage is higher than a second threshold voltage, the current limiting circuit lowers the charging current substantially to zero. | 08-02-2012 |
| 20080232141 | Power System with Power Converters Having an Adaptive Controller - A power system having a power converter with an adaptive controller. In one embodiment, a power converter coupled to a load includes a power switch configured to conduct for a duty cycle to provide an output characteristic at an output thereof. The power converter also includes a power converter controller configured to receive a signal from the load indicating a system operational state of the load and enable a power converter topological state as a function of the signal. | 09-25-2008 |
| 20080232140 | System for transferring an alternating voltage into a direct voltage - A system for transferring an alternating voltage into a direct voltage includes a rectifier, a filter, a transformer, a switch, a switch control circuit and a voltage feedback circuit. The rectifier connects to a main power supply device and rectifies the alternating voltage into a transient direct voltage. The filter filters out a noise from the transient direct voltage and produces a filtering direct voltage. The transformer transfers the filtering direct voltage into a working direct voltage. The switch which has a turn-on status and a cutoff status is used to control the current which goes through the transformer. The switch control circuit is used to control the switch be in the turn-on status or the cutoff status. The voltage feedback circuit drives the switch controlling circuit in accordance with the transformer's voltage and diminishes a switching loss from the switch. | 09-25-2008 |
| 20100238688 | POWER SUPPLY APPARATUS - The DC power supply apparatus includes a switching operation control part that is provided between a current detection part to detect a current flowing through a primary coil of a transformer and a control part to control the operation of a switching part and controls the operation of the switching part according to an output voltage so that consumption power in a low-load state can be further reduced. | 09-23-2010 |
| 20100128500 | SWITCHING POWER CONVERSION CIRCUIT - A switching power conversion circuit includes a power circuit, a feedback circuit and a control circuit. The power circuit includes a switching circuit and a first magnetic element. The first magnetic element generates a magnetic flux change by alternately conducting or shutting off the switching circuit, so that an input voltage is converted into the output voltage by the power circuit. The feedback circuit generates a feedback signal according to the output voltage. The control circuit is used for controlling an on duration and an off duration of the switching circuit, thereby maintaining the output voltage at a rated voltage. The off duration of the switching circuit is maintained at a constant interval under control of the control circuit. The on duration of the switching circuit is adjusted to be a specified interval smaller than a maximum on duration according to the magnitude of the input voltage. | 05-27-2010 |
| 20090040791 | ENHANCEMENT OF POWER CONVERSION EFFICIENCY USING DYNAMIC LOAD DETECTING AND TRACKING - A switching mode power converter may include a modulation circuit to dynamically control a variable switching frequency of the power converter based on an error voltage of the power converter. The power converter may also include a control circuit connected to the modulation circuit and arranged to dynamically limit an inductor current in the power converter while the switching frequency of the power converter changes. A variable limit on the inductor current may be based on the error voltage of the power converter, a load current of the power converter, or information from a power manager of a system in which the power converter resides. In some implementations, the power converter may also include a disabling circuit to control the modulation circuit to disable the variable switching frequency when a sufficiently large load transient is detected. | 02-12-2009 |
| 20110032730 | SAMPLING CIRCUIT AND CONTROL METHOD - An embodiment provides a sampling circuit, which has a sampling capacitor and a voltage compensation circuit. The voltage compensation circuit has a reference capacitor and a compensation circuit. The sampling capacitor samples a voltage signal and memorizes the signal as a sampling signal. The reference capacitor memorizes a reference signal with a predetermined value. The compensation circuit changes the reference signal with a recovery amount to recover the reference signal to the predetermined value, and simultaneously changes the sampling signal with an adjustment amount. | 02-10-2011 |
| 20100302812 | ADAPTER POWER SUPPLY - The present invention relates to an adapter power supply, which includes a switching unit for switching a DC voltage; a transformer which has a primary winding connected to the switching unit, a secondary winding electromagnetically coupled to the primary winding, and an auxiliary winding electromagnetically coupled to the primary winding; a rectifier for rectifying a voltage outputted from the transformer; and a controller for controlling the switching unit to operate according to the PWM scheme in a normal operation mode, and to operate according to a quasi-resonant scheme in a standby mode, by detecting information of a load connected to the rectifier. | 12-02-2010 |
| 20100302814 | CONTROLLER FOR SWITCHING POWER SUPPLY - A switching power supply has an inductor that includes a coil. A chopper circuit chops the primary current drawn through the coil, for the inductor to output an induced current. A multifunction junction of the power supply has a multifunction voltage that is a function of a primary voltage that drives the coil. A first circuit suspends the chopping in response to a first sensed voltage crossing a first threshold, the first sensed voltage being a function of the multifunction voltage. A second circuit suspends the chopping in response to a second sensed voltage crossing a second threshold, the second threshold being a function of the multifunction voltage. | 12-02-2010 |
| 20100302813 | DUAL-MODE CONSTANT LOAD CONTROL CIRCUITS AND ASSOCIATED METHODS - Dual-mode AC/DC power converters and associated methods of operation are disclosed herein. In one embodiment, the AC/DC converter includes a primary winding, a switching transistor coupled to the primary winding, the switching transistor configured to carry a drain-source current, and a feedback voltage port configured to carry a feedback voltage. The feedback voltage port is coupled to the switching transistor to switch off the switching transistor when the drain-source current reaches a peak current limit. The peak current limit increases with increasing feedback voltage if and only if the feedback voltage satisfies an ordered relationship with a threshold. | 12-02-2010 |
| 20090034301 | Switching Power Converter Controlled by a Winding Voltage Sampler - This invention discloses a switching power converter controlled by a winding voltage sampler, including an input circuit with an input end, an output circuit with an output end, one or more switches, a controller to regulate on/off of the switch, a winding voltage sampler, and a transformer including a primary-side coil assembly connecting the switch and the winding voltage sampler, and a secondary-side coil assembly. The output circuit connects the secondary-side coil assembly; the winding voltage sampler detects preset reference voltage of the primary-side coil assembly for the controller to regulate output voltage | 02-05-2009 |
| 20120243265 | CONTROL DEVICE FOR DC/DC CONVERTER - Disclosed herein is a control device for a DC/DC converter, in which FB control and FF control are combined to estimate an output voltage of a nonlinear dynamic system while guaranteeing stability. The control device includes a FB controller which generates a first time value for switch-off timing as the amount of feedback control, a machine learning controller which generates a second time value for switch-off timing as the amount of FF control, and a difference time calculator which obtains a difference between the first time value and the second time value and transmits a difference signal to the drive circuit. The machine learning controller calculates a second time value by multiplying the deviation between the target value of the machine learning control and the estimation value from leaning history in certain sampling by α=A·e×p(−λ×n) (A: a factor (except for zero) for suppressing the first undershoot, λ: a factor (constant except for zero) for suppressing the second undershoot, and n: an integer indicating the nth sampling). | 09-27-2012 |
| 20100053999 | Switching Mode Power Supply And The Driving Method Thereof - The present invention relates to a switching mode power supply and a driving method thereof. In the present invention, a supply voltage is generated by using a start voltage that corresponds to input power, and a switching operation frequency of a power switch is changed according to an increase/decrease of the supply voltage. | 03-04-2010 |
| 20100135048 | SWITCHING POWER SUPPLY DEVICE AND METHOD OF STARTING THE SAME - To reduce power loss during standby. | 06-03-2010 |
| 20110075449 | Compact Power Transformer Components, Devices, Systems and Methods - Disclosed herein are various embodiments of compact coil power transformers configured to provide high voltage isolation and high voltage breakdown performance characteristics in small packages. Compact coil transformers are provided across which power may be transmitted and received by primary and secondary coils disposed on opposing sides of a substrate without high voltage breakdowns occurring therebetween. At least portions of the compact coil transformer are formed of an electrically insulating, non-metallic, non-semiconductor, low dielectric loss material. The compact coil transformers may be formed in small packages using, by way of example, printed circuit boards, flex circuits, lead frames, CMOS and other fabrication and packaging processes. | 03-31-2011 |
| 20100302811 | SINGLE-STAGE POWER SUPPLY WITH POWER FACTOR CORRECTION AND CONSTANT CURRENT OUTPUT - An example controller includes first, second and third inputs, a delayed ramp generator and a drive signal generator. The first, second and third inputs are coupled to receive an input voltage sense signal, an output voltage sense signal, and an input current sense signal, respectively. The drive signal generator is coupled to receive an input charge control signal generated by an input charge control signal generator and a delayed ramp signal generated by a delayed ramp generator. The input charge control signal is generated responsive to an integral of the input current sense signal multiplied by a ratio of the input voltage sense signal to the output voltage sense signal, where the drive signal generator produces a drive signal responsive to the input charge control signal and the delayed ramp signal, the drive signal to be coupled to control a switch of a power supply to regulate an output of the power supply. | 12-02-2010 |
| 20100309690 | SWITCHING POWER SUPPLY APPARATUS AND SEMICONDUCTOR DEVICE - The switching power supply apparatus according to the present invention includes: a transformer including a primary winding, a secondary winding, and an auxiliary winding; a switching device connected to the primary winding; an output voltage generation circuit which is connected to the secondary winding and generates an output voltage; an auxiliary power voltage generation circuit which is connected to the auxiliary winding and generates an auxiliary power voltage; and a control circuit which operates using the auxiliary power voltage and controls a driver circuit so that an intermittent oscillation is performed when the output voltage is higher than a first output voltage and controls a peak of a current flowing through a switching device is lower than a peak in a normal mode, when the auxiliary power voltage is lower than a first auxiliary power voltage in the intermittent oscillation. | 12-09-2010 |
| 20080219032 | METHOD AND SYSTEM FOR OPERATING A POWER CONVERTER - A method and system for operating a power converter having an electrical component and a switch coupled to a voltage source are provided. A signal is received that is representative of a desired current flow through the electrical component. A signal is generated that is representative of a difference between the desired current flow and an actual current flow through the electrical component. A duty cycle for the switch is calculated based on the signal representative of the difference and a voltage generated by the voltage source. | 09-11-2008 |
| 20080219031 | Apparatus and methods for improving the transient response capability of a switching power supply - The transient response of a switching power supply is improved by providing one or more supplemental power sources connected to the output terminal of the power supply. In one embodiment additional current is provided when a sudden increase in load current causes a corresponding decrease in output voltage. In one embodiment current is discharged when a sudden decrease in load current causes a corresponding increase in output voltage. The supplemental power sources provide a fixed current for a fixed duration. In one embodiment the current provided from the power sources is variable according to the increase or decrease in load current. In some embodiments the supplemental current is provided for a time period approximating the time required for the switching power converter coil current to equal the new load current. | 09-11-2008 |
| 20100165667 | Power System with Power Converters Having an Adaptive Controller - A power system having a power converter with an adaptive controller. The power system is coupled to a load and includes a power system controller that receives a signal indicating a system operational state of the load and selects a power converter operational state as a function thereof. The power system also includes a power converter with a power switch that conducts for a duty cycle to provide a regulated output characteristic at an output thereof. The power converter also includes a controller that receives a command from the power system controller to enter the power converter operational state and provides a signal to control the duty cycle of the power switch as a function of the output characteristic and in accordance with the command, thereby regulating an internal operating characteristic of the power converter to improve an operating efficiency thereof as a function of the system operational state. | 07-01-2010 |
| 20100165666 | PRIMARY-SIDE FEEDBACK CONTROL DEVICE AND RELATED METHOD FOR A POWER CONVERTER - A primary-side feedback control device for a power converter includes a control unit for generating a pulse signal according to a feedback signal for controlling on and off states of a switching transistor of the power converter, a comparator coupled to an auxiliary winding of a primary side of the power converter for generating at least one control signal according to a voltage on the auxiliary winding and a reference voltage, a sample-and-hold unit coupled to the auxiliary winding, the comparator, and the control unit for generating the feedback signal according to the voltage on the auxiliary winding and the at least one control signal, and a voltage generator coupled to the control unit, the comparator, and the sample-and-hold unit for generating the reference voltage according to the feedback signal. | 07-01-2010 |
| 20100067259 | FORWARD-FLYBACK CONVERTER WITH ACTIVE-CLAMP CIRCUIT - The present invention discloses a forward-flyback converter with active-clamp circuit. The secondary side of the proposed converter is of center-tapped configuration to integrate a forward circuit and a flyback circuit. The flyback sub-circuit operating continuous conduction mode is employed to directly transfer the reset energy of the transformer to the output load. The forward sub-circuit operating discontinuous conduction mode can correspondingly adjust the duty ratio with the output load change. Under the heavy load condition, the mechanism of active-clamp flyback sub-circuit can provide sufficient resonant current to facilitate the parasitic capacitance of the switches to be discharged to zero. Under the light load condition, the time interval in which the resonant current turns from negative into positive is prolonged to ensure zero voltage switching function. Meanwhile, the flyback sub-circuit wherein the rectifier diode is reverse biased is inactive in order to further reduce the power losses. | 03-18-2010 |
| 20090175055 | Power supplying device - A power supplying device includes: an output transformer including first and second output coils for generating first intermediate voltages from an input voltage; a voltage adjusting transformer including primary and secondary coils; a first rectifying-and-filtering circuit connected to the first output coil for generating a first output voltage from the first intermediate voltage obtained from the first output coil; the primary coil being connected in parallel to the first output coil, the secondary coil being connected in series to the second output coil and being coupled to the primary coil for generating a second intermediate voltage from the first intermediate voltage obtained from the first output coil; and a second rectifying-and-filtering circuit connected to the secondary coil for generating a second output voltage from a combined voltage combining the second intermediate voltage obtained from the secondary coil with the first intermediate voltage obtained from the second output coil. | 07-09-2009 |
| 20120307530 | POWER SUPPLY DEVICE AND METHOD FOR CONTROLLING SAME - In a normal operation, a switch control circuit in a control IC for switching power supply operates to control an opening and closing operation of a switching element. When a remote control receiving circuit issues an instruction to perform a standby operation, an energy saving switch is opened in a period elapsed until an output voltage of a rectification/smoothing circuit for secondary output winding falls below a predetermined value. Thus, an operation of a switch control circuit in the control IC for switching power supply is stopped such that the opening and closing operation of the switching element is not performed. In this case, the remote control receiving circuit and a timer microcomputer are operable with electric power based on a voltage at a smoothing capacitor in the rectification/smoothing circuit for secondary output winding. | 12-06-2012 |
| 20110305043 | ISOLATED SWITCHING POWER SUPPLY APPARATUS - A control IC including a full-bridge circuit is disposed on a primary side and a secondary side. Bidirectional communication is performed between the primary side and the secondary side in a state in which they are isolated. A control signal output from the primary side or the secondary side earlier is preferentially processed. As a result, the authority to control a switching element can be freely given to a primary-side control IC or a secondary-side control IC, and any control processing can be performed with software. | 12-15-2011 |
| 20110317451 | REVERSE CURRENT LIMIT PROTECTION FOR ACTIVE CLAMP CONVERTERS - DC-to-DC converters are protected from damage by, among other things, monitoring and controlling forward and reverse currents in their transformer primary windings. The currents are discontinued if their values fall outside a predetermined range or if they flow during a portion of the switching cycle in a manner that would result in cross-conduction. Power switches in these converters are also protected from damage by adjusting the maximum duty cycles of these converters to vary with their input voltages. In this way, the maximum voltage across the power switches is kept within a relatively narrow range. These protective features can be combined in any number of ways to fit the application at hand. | 12-29-2011 |
| 20100195354 | FULL-RANGE-DUTY PWM SIGNAL GENERATION METHOD, APPARATUS, AND SYSTEM USING SAME - The present invention discloses a full-range-duty PWM signal generation method for an AC-to-DC power conversion, comprising the steps of: generating a saw-tooth signal with a predetermined valley voltage; generating a reference signal according to at least one of a current feedback signal and a voltage feedback signal; and generating a PWM signal according to voltage comparison of the saw-tooth signal and the reference signal. Furthermore, the present invention also provides a full-range-duty PWM signal generation apparatus for an AC-to-DC power conversion, and a system using the full-range-duty PWM signal generation apparatus. | 08-05-2010 |
| 20100254165 | POWER SUPPLY - A switching “power ( | 10-07-2010 |
| 20120113685 | POWER SUPPLY SYSTEM AND IMAGE FORMING APPARATUS - A power supply system includes: a switching power supply; and a control device, wherein the switching power supply includes: a transformer; a semiconductor switching element; a switch control unit; and a rectifying/smoothing circuit, the switch control unit is supplied with power from the main power supply, starts to control the switching of the semiconductor switching element, and oscillates a primary side of the transformer to induce a voltage on the secondary side of the transformer, the control device outputs a control pulse signal to the switch control unit to stop the oscillation of the transformer, thereby changing the mode of the switching power supply to an output stop mode, in an output mode in which the switching power supply smoothes the voltage induced on the secondary side and outputs the smoothed voltage. | 05-10-2012 |
| 20120113684 | Compensation Circuit for Constant Current Regulation of Power Supply and Method Thereof - A compensation circuit and method for constant current regulation of switching mode power supply are disclosed. The ringing waveform of a feedback signal, indicative of the output current of the power supply, causes error. To eliminate the error, a current source charges a capacitor in response to a demagnetizing oscillation signal indicative of the error caused by the ringing waveform of the feedback signal. The voltage across the capacitor is compared to a reference signal to generate a more accurate signal indicative of the conductive time of a secondary diode in a secondary winding of the switching mode power supply. This more accurate signal is inputted to a logic circuit to generate a constant current control signal to control a power switch of the power supply. | 05-10-2012 |
| 20090147545 | HISTORY-INDEPENDENT NOISE-IMMUNE MODULATED TRANSFORMER-COUPLED GATE CONTROL SIGNALING METHOD AND APPARATUS - A history-independent and noise-immune modulated transformer-coupled gate control signaling method and apparatus provides robust design characteristics in switching power circuits having a transformer-coupled gate drive. A modulated control signal at a rate substantially higher than the switching circuit gate control rate is provided from the controller circuit to a demodulator via transformer coupling. Codes specified by relative timing of transitions in multiple periods of the modulated control are assigned to gate-on and gate-off timing events that control the switching transistor gate(s) and unassigned patterns are decoded as gate-off events, reducing the possibility that a switching transistor will be erroneously activated due to noise. The modulated signal is constructed so that signal history is not required for decoding, eliminating any requirement of a reference clock. Blanking may be employed to conserve power between codes and to avoid mis-triggering due to noise events during power switching. | 06-11-2009 |
| 20110090716 | DC-DC CONVERTER WITH SNUBBER CIRCUIT - In order to achieve an object to reduce a surge voltage and suppress noise generation, the present invention provides a DC-DC converter with a snubber circuit, which boosts a voltage Vi of a DC power supply. The snubber circuit includes: a series circuit connected to both ends of a smoothing capacitor Co and including a snubber capacitor Cs and a snubber resistor Rs; a snubber diode Ds | 04-21-2011 |
| 20120120685 | CONTROL METHOD AND CONTROL MODULE FOR CONTROLLING AN ASYMMETRIC DC-DC CONVERTER - A control method is provided for controlling an asymmetric DC-DC converter including first and second power switches that are driven respectively by first and second control signals, and a voltage-converting circuit that is operatively associated with the first and second power switches for generating an output signal. The voltage-converting circuit includes a primary coil unit and a secondary coil unit operatively associated therewith for voltage conversion, and including first and second coils that have a turn ratio not equal to one. The control method includes: sampling the output signal to obtain a sample signal corresponding thereto; and generating the first and second control signals, which correspond respectively to first and second duty cycles having a sum of one, based on a comparison between the sample signal and a reference signal such that the first and second power switches are driven in an alternating manner. | 05-17-2012 |
| 20100091524 | Electronic Power Protection Circuit And Applications Thereof - An electric power protection circuit connected in series to a secondary side circuit of a transformer in a switch mode power supply includes a voltage/current limiting device to get an electric power signal output from the secondary side circuit of the transformer that goes through current and voltage limitation before being output and a constant current/voltage controller to get the electric power signal which has the current and voltage limited by the voltage/current limiting device. The electric power signal further is undergone constant voltage/current control to achieve voltage overshoot protection. | 04-15-2010 |
| 20120314454 | SWITCHING POWER SUPPLY APPARATUS - In a switching power supply apparatus, a first switching element is controlled by a driving voltage output from a switching control IC. A second switching control circuit controls the on-time of a second switching element so that the time ratio of the on-time of the second switching element to the on-time of the first switching element becomes almost constant with respect to a change in a load current. In a normal load state, since a square wave output from a frequency setting unit within the switching control IC is output with no change, a converter operates in a current-continuous mode. In a light load state, a driving signal generation unit within the switching control IC is subjected to blanking with the period of a signal output from a maximum frequency setting unit and an oscillation frequency is reduced. Accordingly, the converter operates in a current-discontinuous mode. | 12-13-2012 |
| 20120314453 | ELECTRONIC CIRCUIT CONTROL ELEMENT WITH TAP ELEMENT - An example control element for use in a power supply includes a high-voltage transistor and a control circuit to control switching of the high-voltage transistor. The high-voltage transistor includes a drain region, source region, tap region, drift region, and tap drift region, all of a first conductivity type. The transistor also includes a body region of a second conductivity type. An insulated gate is included in the transistor such that when the insulated gate is biased a channel is formed across the body region to form a conduction path between the source region and the drift region. A voltage at the tap region with respect to the source region is substantially constant and less than a voltage at the drain region with respect to the source region in response to the voltage at the drain region exceeding a pinch off voltage. | 12-13-2012 |
| 20100067260 | POWER SUPPLY - In a switched mode power supply, and in accordance with a method for operating a switched mode power supply, the magnitude of each occurrence of a current flowing during operation of a power output switch is sensed for negative feedback control. A sense voltage is generated proportional to the primary supply voltage. Whenever the sense voltage exceeds a threshold, output power of the power supply is limited by increasing the sensed magnitude of each occurrence of the flowing currents by adding to each sensed magnitude a voltage proportional to the sense voltage. Threshold voltages can be selected by using Zener diodes having different breakdown voltages. Respective ranges within the overall range of the primary supply voltage in which supplemental power limiting occurs and does not occur can thus be controlled. | 03-18-2010 |
| 20120212978 | Low Power Switch Mode Power Supply - A device and a method for operating a low power switch mode power supply, where OC input power is converted to AC power by an oscillator, which AC power is transformed to an AC voltage and AC current, which output power is converted into DC power, where the DC voltage is used as a feedback signal for controlling the oscillator. It is the object of the invention to reduce a standby power consumption of power consuming devices. The oscillator comprises a first and a second current loop, which first current loop generates an activation current for the second current loop, where the primary coil of a transformer is part of the second current loop, and where the second loop comprises a current/voltage measuring system and generates increasing current in the second current loop and closes the current flow in the second current loop. | 08-23-2012 |
| 20120176816 | STARTING UP A DC/DC CONVERTER HAVING A HIGH-FREQUENCY TRANSFORMER - During startup of a DC/DC converter having a high-frequency transformer whose primary winding is supplied with current from an input-side DC link via an inverter bridge having pulsed switches and whose secondary winding is used to charge an output-side DC link via a rectifier bridge. The switches of the inverter bridge are operated to load the output-side DC link, in a manner that deviates from a normal operation of the switches in order to limit the currents that flow in the DC/DC converter during startup of the DC/DC converter. Particularly, the switches of the inverter bridge are operated during startup of the DC/DC converter at a pulse width that is fixed during each of a limited number of stages of the startup, and have a duty cycle that is not more than 5 percent during each of the stages of the startup. | 07-12-2012 |
| 20120188796 | POWER COUPLING SYSTEM AND METHOD - Systems and methods for the coupling of power through an isolation transformer. The systems generally include a primary side electrically connectable to the primary winding of an isolation transformer, a secondary side electrically connectable to the secondary winding of the isolation transformer, a primary side switch sending power pulses to the secondary side, and a secondary side feedback circuit sending a feedback signal to the primary side. A pulse detector sends power pulses to the secondary side in response to the feedback signal, while a watchdog timer sends a power pulse to the secondary side if a feedback signal is not detected within a predetermined period of time. Secondary side circuits including a slow-start circuit and a wake circuit portion manage initialization and low-load operating power requirements, respectively. | 07-26-2012 |
| 20120230062 | DC-DC CONVERTER - A DC-DC converter includes a series circuit including a primary transformer coil and a main switch element connected between a power input terminal and a ground terminal. A secondary transformer coil is connected to a rectifying/smoothing circuit including rectification-side and commutation-side synchronous rectifiers, a smoothing capacitor, and a choke coil. The output voltage from the rectifying/smoothing circuit is supplied to a load connected to a power output terminal. An input voltage detection circuit detects the voltage between the power input terminal and the ground terminal, and supplies a detection signal to a VIN terminal of a switching control circuit. The switching control circuit performs PWM control to maintain a constant output voltage output to the load, reduces the switching frequency when the input voltage input to the VIN terminal is low, and increases the switching frequency in accordance with an increase in the input voltage. | 09-13-2012 |
| 20080298092 | Control circuit and method for controlling switching power supply - Control circuit and method for controlling a switching power supply, which regulates its output voltage using pulse-width modulation (PWM) that switches on and off a main switch with a PWM signal (VCONT) at an adjusted ON-period ratio of the main switch. The control circuit includes an error signal amplifier circuit that compares the output voltage with a reference voltage and outputs an error signal VE based on the comparison. The control circuit also includes an ON-period adjusting circuit that starts generating a PWM signal (VCONT) in every cycle based on a pulse VPULSE, the period thereof being fixed, and adjusts the HIGH-period of the PWM signal (VCONT) based on the output voltage of the error signal VE. As a result, the control circuit widens the HIGH-period ratio range or the LOW-period ratio range of the PWM signal greatly. | 12-04-2008 |
| 20080298089 | Converter Circuit with Forward and Backward Control - The present invention relates to a converter circuit and a conversion method for converting an input signal of a first value to an output signal of a second value based on a switched operating mode, wherein an output feedback loop ( | 12-04-2008 |
| 20120320634 | METHOD AND APPARATUS FOR A CONTROL CIRCUIT WITH MULTIPLE OPERATING MODES - An example controller for use in a power converter includes an oscillator that is to be coupled to a switch of the power converter to determine a switching cycle period of the switch. The controller also includes means for controlling a duty cycle of the switch to regulate an output of the power converter and for maintaining a substantially constant rate of change of the duty cycle with respect to changes in a magnitude of a feedback signal as the controller transitions between duty cycle control modes such that a control loop gain of the power converter is substantially constant during the transition. | 12-20-2012 |
| 20120320633 | VARIABLE FREQUENCY PWM SYNCHRONOUS RECTIFIER POWER SUPPLY - The present invention discloses a variable frequency PWM synchronous rectifier power supply comprising: a transformer, a PWM control circuit and a synchronous rectification switch circuit. The transformer has a primary side and a secondary side, and an isolation circuit is provided for separating the primary side and the secondary side, and the primary side uses a transmit/receive switch circuit to drive the transformer, and the secondary side uses a filter circuit to output different voltages to an external load. The PWM control circuit is situated on the secondary side and coupled to the isolation circuit and filter circuit, for generating a control signal to the isolation circuit to drive the transmit/receive switch circuit. The synchronous rectification switch circuit is situated on the secondary side and coupled to the PWM control circuit for receiving a timing delay control signal provided by the PWM control circuit. | 12-20-2012 |
| 20110273910 | METHOD AND APPARATUS FOR A CONTROL CIRCUIT WITH MULTIPLE OPERATING MODES - An example controller for use in a power converter includes an oscillator and a logic circuit. The oscillator is to be coupled to a switch of the power converter and determines a switching cycle period of the switch. The logic circuit is also to be coupled to the switch to control a duty cycle of the switch in response to a magnitude of a feedback signal to regulate an output of the power converter. The logic circuit controls the duty cycle of the switch such that a control loop gain of the power converter is substantially constant during a transition of the controller between duty cycle control modes. | 11-10-2011 |
| 20120327691 | SWITCHED MODE POWER SUPPLY - A power supply has over power protection based on the same signal as used by the feedback path for controlling the switching of the power supply. This means that no additional signal needs to be supplied to the control circuit to implement mains over protection. | 12-27-2012 |
| 20120287679 | SWITCHING TECHNIQUES TO REDUCE CURRENT OVERSHOOT IN A DC TO DC CONVERTER - A DC/DC converter system includes gate control circuitry, a transformer, a second stage, and soft start control circuitry. The gate control circuitry is configured to generate a first and a second gate control signal configured to open and close first and second switches of an inverter circuitry, respectively, to generate an AC signal from a DC input signal. The transformer transforms the AC signal and the second stage rectifies the AC signal to a DC output signal. The soft start control circuitry generates a signal to delay a closing of the first switch during an initial portion (Td) of a first cycle of the first switch. A method of soft-starting a DC/DC converter includes generating first and second gate control signals and delaying closing of the first switch during Td. | 11-15-2012 |
