| SYSTEM GENERAL CORPORATION Patent applications |
| Patent application number | Title | Published |
|---|
| 20120113551 | Method and Apparatus of Providing Over-Temperature Protection for Power Converters - The present invention provides a power converter. The power converter includes a transformer, a power switch and a controller. The transformer has a primary winding, a secondary winding and an auxiliary winding. The power switch is coupled to the primary winding of the transformer to regulate the power converter. The controller has an output terminal for generating a driving signal to switch the power switch in response to a switching signal. A thermal resistor is coupled to the output terminal of the controller. The driving signal is adjusted across the thermal resistor during an off-period of the switching signal. | 05-10-2012 |
| 20120081084 | Controller with Valley Switching and Limited Maximum Frequency for Quasi-Resonant Power Converters - A controller for a power converter is provided. The controller includes a PWM circuit, a detection circuit, a signal generation circuit and an oscillation circuit. The PWM circuit generates a switching signal coupled to switch a transformer of the power converter. A feedback signal is coupled to the PWM circuit to disable the switching signal. The detection circuit is coupled to the transformer via a resistor for generating a valley signal in response to a signal waveform of the transformer. The signal generation circuit is coupled to receive the feedback signal and the valley signal for generating an enabling signal. The oscillation circuit generates a maximum frequency signal. The maximum frequency signal associates with the enabling signal to generate a pulse signal. The feedback signal is correlated to an output load of the power converter. The maximum frequency of the pulse signal is limited. | 04-05-2012 |
| 20120069611 | Correction Circuit of a Switching-Current Sample for Power Converters in Both CCM and DCM Operation - The present invention provides a correction circuit for a power converter. The correction circuit includes a sampling circuit, a demagnetizing-time circuit, a duty circuit, and a compensation circuit. The sampling circuit generates an average-current signal in response to a switching current of the power converter. The demagnetizing-time circuit generates a discharging-time signal in response to a switching signal and an input-voltage signal. The duty circuit generates a duty signal in response to the discharging-time signal, an on-time of the switching signal, and a switching period of the switching signal. The compensation circuit is coupled to receive the average-current signal and the duty signal for generating a corrected signal. The switching signal is utilized to switch a magnetic device for regulating an output voltage of the power converter. The corrected signal is coupled to generate the switching signal. | 03-22-2012 |
| 20120043843 | MOTOR ROTOR AND MOTOR HAVING THE MOTOR ROTOR - A motor rotor includes an annular body and a positioning protrusion installed on an inner lateral surface of the annular body. A magnetic body may be positioned by propping its lateral surface against the positioning protrusion, without the use of additional jigs. Therefore, the time needed to assemble the magnetic body to the annular body is saved, and the manufacturing cost of the whole motor is reduced. | 02-23-2012 |
| 20120033460 | High-Side Synchronous Rectifier Circuits and Control Circuits for Power Converters - A control circuit for a switching power converter is provided. The control circuit is installed between a secondary side and an output of the power converter and coupled to control a switching device. The control circuit includes a linear predict circuit, a reset circuit, a charge/discharge circuit, and a PWM circuit. The linear predict circuit is coupled to receive a linear predict signal from the secondary side for generating a charging signal. The reset circuit is couple to receive a resetting signal for generating a discharging signal. The charge/discharge circuit is coupled to receive the charging signal and the discharging signal for generating a ramp signal. The PWM circuit is coupled to receive the linear predict signal for enabling a switching signal and receive the ramp signal for resetting the switching signal. | 02-09-2012 |
| 20120025655 | MOTOR ROTOR AND MOTOR HAVING THE MOTOR ROTOR - A motor rotor includes an annular body and a magnetic body installed on an inner lateral surface of the annular body. The magnetic body has a first curved surface and a second curved surface opposing the first curved surface. The magnetic body props against the inner lateral surface of the annular body via the first curved surface. The first curved surface has a first curvature less than a second curvature of the second curved surface. Because the magnetic body of the motor rotor has an uneven thickness, and an air gap interval formed between the motor rotor and the stator also has an uneven width, forces applied to a region where the magnetic forces change directions are smooth. Therefore, the vibration of the whole motor is reduced, and the noises are suppressed effectively. | 02-02-2012 |
| 20110305053 | Switching Control Circuits with Valley Lock for Power Converters - A switching control circuit for a switching power converter is provided. The switching control circuit is coupled to a switching device and an auxiliary winding of a transformer. The switching control circuit includes a valley detecting circuit, a valley lock circuit, and a PWM circuit. The valley detecting circuit is coupled to receive a reflected voltage signal from the auxiliary winding of the transformer for outputting a control signal in response to the reflected voltage signal. The valley lock circuit is coupled to receive the control signal for outputting a judging signal in response to the control signal during a first period and a second period following the first period. The PWM circuit outputs a switching signal in response to the judging signal. | 12-15-2011 |
| 20110292702 | METHOD AND APPARATUS TO IMPROVE DYNAMIC RESPONSE OF THE SYNCHRONOUS RECTIFYING FOR RESONANT POWER CONVERTERS - A synchronous rectifying circuit for a switching power converter is provided. The synchronous rectifying circuit includes a power transistor, a diode, and a control circuit. The power transistor and the diode are coupled to a transformer and an output of the power converter for rectification. The control circuit generates a drive signal to switch on the power transistor once the diode is forward biased. The control circuit includes a monitor circuit. The monitor circuit generates a monitor signal an off signal to switch off the power transistor in response to a pulse width of the drive signal for generating an off signal to switch off the power transistor. The monitor circuit further reduces the pulse width of the drive signal in response to a change of a feedback signal. The feedback signal is correlated to an output load of the power converter. | 12-01-2011 |
| 20110267850 | Method and Apparatus of Operating a Primary-Side-Regulation Power Converter at Both Continuous Current Mode and Discontinuous Current Mode - A method and an apparatus of operating a primary-side-regulation power converter at both continuous current mode and discontinuous current mode are provided. The apparatus includes a switching circuit, a signal generator, a correlation circuit, and a feedback modulator. The signal generator generates a half signal and a second sampling pulse in response to a switching signal. The correlation circuit receives the half signal, the second sampling pulse and a switching-current signal for generating a modulating current. The feedback modulator modulates a feedback signal in response to the modulating current, a detection signal and the switching signal. The detection signal obtained from a transformer is correlated to an output voltage of the primary-side-regulation power converter. An on-period of the half signal is half of an on-period of the switching signal. The switching-current signal is sampled at a falling-edge of the half signal. | 11-03-2011 |
| 20110255309 | High-Speed Reflected Signal Detection for Primary-Side Controlled Power Converters - A controller for a power converter includes a clamping circuit, a switching circuit and a pulse generator. The clamping circuit is coupled to an input terminal of the controller for detecting a detection signal from a transformer. The switching circuit generates a switching signal to switch the transformer in response to the detection signal for regulating the power converter. A maximum level of the detection signal is clamped to be under a level of a threshold voltage during an off-period of the switching signal. Since the maximum level of the detection signal is clamped and the oscillating energy of the reflected signal is discharged, the speed of detecting the detection signal is increased. Therefore, the regulation of the primary-side controlled power converter can be improved accordingly. | 10-20-2011 |
| 20110254498 | Constant-Speed Control Circuit for BLDC Motors - A speed-control circuit for a BLDC motor is provided. The speed-control circuit includes a pulse generator, a current source circuit, a filter circuit, an error amplification circuit and a PWM circuit. The pulse generator detects a speed signal of the BLDC motor to generate a pulse signal. The filter circuit is coupled to the current source circuit to generate an average signal. The error amplification circuit receives the average signal and a speed-reference signal for generating a speed-control signal. The PWM circuit generates a switching signal to drive the BLDC motor in response to the speed-control signal. A pulse width of the switching signal is determined by the speed-control signal. | 10-20-2011 |
| 20110038183 | SWITCHING REGULATOR HAVING TERMINAL FOR FEEDBACK SIGNAL INPUTTING AND PEAK SWITCHING CURRENT PROGRAMMING - A switching regulator of a power converter is provided and includes a feedback-input circuit, a programming circuit, and a peak-current-threshold circuit. The feedback-input circuit is coupled to a terminal of the switching regulator for receiving a feedback signal. The feedback-input circuit is operated in a first range of a terminal signal. The programming circuit is coupled to the terminal for generating a programming signal. The programming signal is operated in a second range of the feedback signal. The peak-current-threshold circuit generates a threshold signal in accordance with the programming signal. The feedback signal is coupled to regulate the output of the power converter, and the threshold signal is coupled to limit a peak switching current of the power converter. | 02-17-2011 |
| 20110037443 | PARALLEL CONNECTED PFC CONVERTER - A parallel PFC converter comprises a first PFC circuit, a second PFC circuit, and a voltage divider. The second PFC circuit is connected in parallel with the first PFC circuit for generating an output voltage of the parallel PFC converter. The voltage divider is coupled to receive the output voltage for generating a first feedback signal and a second feedback signal. The first feedback signal is higher than the second feedback signal. The first PFC circuit and the second PFC circuit respectively comprises a first switching control circuit and a second switching control circuit for regulating the output voltage. It is an object of the present invention to reduce the power loss for improving the efficiency of the PFC converter. | 02-17-2011 |
| 20100309645 | MOUNTING STRUCTURE FOR AN ELECTRONIC ELEMENT - A mounting structure for fixing an electronic element on a heat dissipation unit is provided. The mounting structure includes a heat dissipation unit, a fixing member, electronic elements and elastic elements. The fixing member is fixed on the heat dissipation unit. The elastic elements are sandwiched between the electronic elements and the fixing member, wherein the fixing member and the elastic elements press the electronic elements to make the electronic elements tightly contact the heat dissipation unit. | 12-09-2010 |
| 20100232182 | DUAL-SWITCHES FLYBACK POWER CONVERTER WITH SELF-EXCITED SUPPLY TO POWER THE HIGH-SIDE DRIVER - An exemplary embodiment of a flyback power converter includes a transformer for power transfer, a high-side transistor, a low-side transistor, two diodes, a control circuit, and a high-side drive circuit. The high-side transistor and the low-side transistor are coupled to switch the transformer. The two diodes are coupled to said transformer to circulate energy of leakage inductance of the transformer to an input power rail of the power converter. The control circuit generates a switching signal coupled to control the high-side transistor and the low-side transistor. The high-side drive circuit is coupled to receive the switching signal for driving the high-side transistor. The transformer has an auxiliary winding generating a floating power to provide power supply for said high-side drive circuit. | 09-16-2010 |
| 20100230749 | SEMICONDUCTOR DEVICES AND FORMATION METHODS THEREOF - A semiconductor device is provided and includes a substrate of a first conductivity type, a deep well of a second conductivity type, and a first high-side device. The deep well is formed on the substrate. The first high-side device is disposed within the deep well and includes an insulation layer of the second conductivity type, a well of the first conductivity type, first and second regions of the second conductivity type, and a first poly-silicon material. The insulation layer is formed on the substrate. The well is formed within the deep well. The first and second regions are formed within the well. The first poly-silicon material is disposed between the first region and the second region and on the deep well. | 09-16-2010 |
| 20100202163 | FLYBACK POWER CONVERTERS - A dual-switch flyback power converter includes a control circuit to generate a switching signal. A high-side driving circuit includes a pulse generation circuit. The pulse generation circuit generates a pulse-on signal and a pulse-off signal to control two transistors in response to the switching signal. The two transistors further respectively provide a level-shift-on signal and a level-shift-off signal to a comparison circuit to enable/disable a high-side driving signal. Without using a charge pump circuit to power the high-side driving circuit, a floating winding of a transformer is utilized to provide a floating voltage to power the high-side driving circuit, which reduces the cost of the dual-switch flyback power converter and ensures a sufficient high-side driving capability of the high-side driving circuit. | 08-12-2010 |
| 20100202162 | ASYMMETRICAL RESONANT POWER CONVERTERS - A resonant power converter is provided and includes a capacitor, an inductive device, a first transistor, a second transistor, and a control circuit. The capacitor and the inductive device develop a resonant tank. The first transistor and the second transistor are coupled to switch the resonant tank. The control circuit generates a first signal and a second signal to control the first transistor and the second transistor respectively. Frequencies of the first signal and the second signal are changed for regulating output of the resonant power converter. The control circuit is further coupled to detect an input voltage of the resonant power converter. A pulse width of the second signal is modulated in response to change of the input voltage. | 08-12-2010 |
| 20100201334 | SYNCHRONOUS RECTIFIER HAVING PHASE LOCK CIRCUIT COUPLED TO FEEDBACK LOOP FOR RESONANT POWER CONVERTERS - A synchronous rectifier for a switching power converter is provided and includes a power transistor, a diode, and a control circuit. The power transistor and the diode are coupled to a transformer and an output of the power converter for the rectification. The control circuit generates a drive signal to switch on the power transistor once the diode is forward biased. The control circuit includes a phase-lock circuit. The phase-lock circuit generates an off signal to switch off the power transistor in response to a pulse width of the drive signal. The pulse width of the drive signal is shorter than a turned-on period of the diode. The phase-lock circuit further reduces the pulse width of the drive signal in response to a feedback signal. The feedback signal is correlated to an output load of the power converter. | 08-12-2010 |
| 20100182804 | SWITCHING CIRCUIT FOR PRIMARY-SIDE REGULATED RESONANT POWER CONVERTERS - The present invention provides a switching circuit to regulate an output voltage and a maximum output current at the primary side of a resonant power converter. The switching circuit includes a pair of switching devices and a controller. The controller is coupled to a transformer to sample a voltage signal thereof and generates switching signals to control the switching devices. The switching frequency of the switching signals is increased in response to the decrease of the output voltage. The increase of the switching frequency of the switching signals decreases the power delivered to the output of the resonant power converter. The output current is therefore regulated. | 07-22-2010 |
| 20100172156 | OFFLINE SYNCHRONOUS RECTIFIER CIRCUIT WITH TURNED-ON ARBITER AND PHASE-LOCK FOR SWITCHING POWER CONVERTERS - A synchronous rectifier circuit of a switching power converter is provided and includes first and second power transistors and first and second diodes connected to a transformer and an output of the power converter for rectifying. An arbiter circuit generates a lock signal to prevent the second power transistor from being turned on when the first diode the first power transistor is turned on. A controller generates a drive signal to control the first power transistor according to an on signal and an off signal. A phase-lock circuit generates the off signal according to the on signal. The on signal is enabled once the first diode is forward biased. The one signal enables the drive signal for turning on the first power transistor. The off signal disables the drive signal for turning off the first power transistor. The off signal is enabled before the disabling of the on signal. | 07-08-2010 |
| 20100123563 | POWER MANAGEMENT INTERFACE - A power management interface is provided and includes a switch, a transmitting circuit, and a receiving circuit. The switch is coupled to an AC power line for controlling a power line signal to a load. The transmitting circuit generates a switching signal to control the switch and achieve a phase modulation to the power line signal in response to a transmitting-data. The receiving circuit is coupled to receive the power line signal for detecting a phase of the power line signal and generating a receiving-data to control power of the load. The receiving-data is generated in accordance with the phase detection of the power line signal and correlated to the transmitting-data. | 05-20-2010 |
| 20100109465 | MOTOR STRUCTURE AND FAN - A motor structure and a fan are provided. The motor structure includes a shaft, a motor control panel, a stator, a rotor and a motor housing. The motor control panel has a first fastening portion and is engageable with the shaft. The stator has a second fastening portion coupled to the first fastening portion so as to fasten the motor control panel to the stator, thereby reducing the overall size and saving costs of materials. The rotor corresponds in position to the stator and is pivotally connected to the shaft. The motor housing is pivotally connected to the shaft and encloses the shaft, the motor control panel, the stator, and the rotor. The fan includes the motor structure and a fan blade element. | 05-06-2010 |
| 20100007317 | BUCK-BOOST PFC CONVERTERS - A buck-boost PFC converter is provided and includes an inductor, first and second transistors, a first diode, and a control circuit. The inductor has a first terminal and a second terminal. The first transistor is coupled to a positive-power rail and the first terminal of the inductor. The second transistor is coupled to the second terminal of the inductor and a negative-power rail. The first diode is connected from the second terminal of the inductor to an output of the buck-boost PFC converter. The control circuit generates a first signal and a second signal coupled to control the first transistor and the second transistor respectively. The first signal is utilized to turn on the first transistor for conducting the positive-power rail to the inductor. The second signal is utilized to turn on the second transistor for conducting the inductor to the negative-power rail. | 01-14-2010 |
| 20100007295 | OVER-TORQUE CONTROL CIRCUIT FOR BLDC MOTORS - A BLDC (brushless direct current) motor system of the present invention includes a control circuit, a sequencer, a driving circuit, and a BLDC motor. The control circuit determines the maximum torque and the maximum speed of the BLDC motor. The control circuit includes an over-current detection circuit to generate a reset signal in response to a switching current of the BLDC motor. The reset signal is generated when the switching current of the BLDC motor exceeds a threshold. A pulse width of the PWM signal is correlated to the level of a speed-control signal and the level of the torque-control signal. The pulse width of the PWM signal is also controlled by the reset signal generated by the over-current detection circuit. | 01-14-2010 |
| 20090310388 | METHOD AND APPARATUS FOR MEASURING THE SWITCHING CURRENT OF POWER CONVERTER OPERATED AT CONTINUOUS CURRENT MODE - An apparatus for detecting a switching current of the power converter, wherein the apparatus includes a signal generation circuit, a sample-and-hold circuit, and a calculating circuit. The signal generation circuit generates a sample signal in accordance with the pulse width of a switching signal. The sample-and-hold circuit is coupled to receive the sample signal and switching current signal for generating a first current signal and a second current signal. The calculating circuit is coupled to receive the first current signal and the second current signal for generating output signals. The switching signal is used for switching the magnetic device of the power converter, and the switching current signal is correlated to the switching current of the power converter; the output signals are correlated to the value of the switching current of the power converter. | 12-17-2009 |
| 20090309526 | CONTROL CIRCUIT WITH DUAL PROGRAMMABLE FEEDBACK LOOPS FOR BLDC MOTORS - A BLDC (brushless direct current) motor system of the present invention includes a control circuit, a sequencer, a driving circuit, and a BLDC motor. The control circuit comprises a speed-feedback loop and a torque-feedback loop to control the maximum speed and the maximum torque of the BLDC motor in parallel configuration. The speed-feedback loop generates a speed-control signal. The torque-feedback loop generates a torque-control signal. A PWM circuit receives the speed-control signal and the torque-control signal to generate a PWM signal. A pulse width of the PWM signal is correlated to the level of the speed-control signal and/or the level of the torque-control signal. | 12-17-2009 |
| 20090309448 | END COVER AND MOTOR ROTOR HAVING THE END COVER - An end cover adapted to engage with an end surface of a spindle of a motor rotor is proposed for securely coupling to the spindle with a plurality of permanent magnets disposed around the peripheral wall of the spindle. The end cover has a first surface facing an end surface of the spindle and an second surface opposing to the first surface, which is formed with a plurality of inserting slots indentedly disposed around the rim thereof and corresponding to the permanent magnets for coupling the ends of the permanent magnets, thereby securely fastening each of the permanent magnets to the spindle of the motor rotor. Further, the present invention further provides a motor rotor having the end covers described above. | 12-17-2009 |
| 20090309441 | SENSOR FASTENING METHOD AND SENSOR FASTENING FRAME FOR USE THEREWITH - A sensor fastening method and a sensor fastening frame for use therewith are provided. The sensor fastening frame is coupled to a motor stator of a brushless motor having distributed coils and extends over the distributed coils to allow the sensor fastening frame to rotate about the axle of a motor rotor, without interference with the distributed coils. At least a sensor is fastened in position to the sensor fastening frame proximate to one end of the axle of the motor stator for positioning the sensor to detect magnetic field variations of the motor rotor. | 12-17-2009 |
| 20090213626 | SWITCHING CONTROLLER CAPABLE OF REDUCING ACOUSTIC NOISE FOR POWER CONVERTERS - The present invention provides a switching controller capable of reducing acoustic noise of a transformer for a power converter. The switching controller includes a switching circuit, a comparison circuit, an activation circuit, and an acoustic-noise eliminating circuit. The acoustic-noise eliminating circuit comprises a first-check circuit, a second-check circuit, a pulse-shrinking circuit, and a limit circuit. The first-check circuit receives a switching-current signal which is correlated to a switching current of the power converter and a PWM signal to generate a trigger signal. The second-check circuit receives the trigger signal to generate a control signal. When the frequency of the trigger signal falls into audio band, the control signal will be enabled to limit the switching current. Therefore, the acoustic noise of the transformer can be eliminated. | 08-27-2009 |
| 20090213623 | METHOD AND APPARATUS OF PROVIDING SYNCHRONOUS REGULATION CIRCUIT FOR OFFLINE POWER CONVERTER - A synchronous regulation circuit is provided. A secondary-side switching circuit is coupled to the output of the power converter to generate a synchronous signal and a pulse signal in response to an oscillation signal and a feedback signal. An isolation device transfers the synchronous signal from the secondary side to the primary side of the power converter. A primary-side switching circuit receives the synchronous signal to generate a switching signal for soft switching a transformer. The pulse signal is utilized to control a synchronous switch for rectifying and regulating the power converter. The synchronous switch includes a power switch and a control circuit. The control circuit receives the pulse signal for turning on or off the power switch. The power switch is connected between the transformer and the output of the power converter. A flyback switch is operated as a synchronous rectifier to freewheel the inductor current of the power converter. The flyback switch is turned on in response to the off state of the power switch. The turn-on period of flyback switch is correlated to the turn-on period of the power switch. | 08-27-2009 |
| 20090195101 | MOTOR ROTOR - A motor rotor is provided. The motor rotor includes a plurality of magnetic members circumferentially disposed on a peripheral wall surface of a turning axle of the motor rotor, and both end surfaces of the turning axle are coupled with fastening members respectively; each of the magnetic members has a first fastening portion formed at each of its two ends; and the fastening member is provided with a plurality of second fastening portions corresponding in position to the first fastening portions, such that each of the magnetic members are firmly fixed in position to the turning axle. | 08-06-2009 |
| 20090109715 | SYNCHRONOUS RECTIFYING FOR SOFT SWITCHING POWER CONVERTERS - An synchronous rectifying apparatus or synchronous rectifying circuit of a soft switching power converter is provided to improve the efficiency. The integrated synchronous rectifying circuit includes: a power transistor connected from a transformer to the output of the power converter for rectifying; a controller having a latch circuit generates a drive signal to control the power transistor in response to a switching signal generated by a winding of the transformer in response to the switching of the transformer. The controller turns off the power transistor when the switching signal is lower than a low-threshold. The power transistor is turned on when the switching signal is higher than a high-threshold. Furthermore, a maximum-on-time circuit provided in the controller is applied to generate a maximum-on-time signal for limiting the maximum on time of the power transistor. | 04-30-2009 |
| 20090091960 | METHOD AND APPARATUS FOR SYNCHRONOUS RECTIFYING OF SOFT SWITCHING POWER CONVERTERS - An apparatus for synchronous rectifying of a soft switching power converter is provided. An integrated synchronous rectifier includes a power transistor coupled between a transformer and the output of the soft switching power converter, and a controller receiving a pulse signal to switch on/off the power transistor. A switching control circuit generates the pulse signal in response to a current signal, and generates drive signals to switch the transformer in response to a switching signal. An isolation device is coupled to transfer the pulse signal between the switching control circuit and the integrated synchronous rectifier. The switching signal is used for regulating the power converter and the current signal is correlated to the switching current of the transformer. | 04-09-2009 |
| 20090091304 | CONTROL CIRCUIT FOR MULTI-PHASE, MULTI-CHANNELS PFC CONVERTER WITH VARIABLE SWITCHING FREQUENCY - A switching control circuit for multi-phases PFC converters is provided. It includes a PFC-control circuit coupled to receive a first-inductor signal and a feedback signal for generating a first-switching signal. The first-switching signal is utilized to switch the first inductor for power factor correction. A phase-detection circuit detects the first-switching signal and a second-inductor signal for generating a start signal and a phase-lock signal. The start signal is developed to enable a second-switching signal. The second-switching signal is coupled to switch a second inductor. An on-time-adjust circuit is coupled to adjust the on time of the second-switching signal in accordance with the phase-lock signal. The phase-lock signal is correlated to the period between the end of the second-inductor signal and the start of the second-switching signal. | 04-09-2009 |
| 20080291701 | POWER CONVERTER FOR COMPENSATING MAXIMUM OUTPUT POWER AND PWM CONTROLLER FOR THE SAME - A PWM controller compensates a maximum output power of a power converter, and includes a PWM unit and a compensation circuit. The PWM unit generates a PWM signal for controlling a power switch to switch a power transformer, which has a primary winding connected to the power switch and is supplied with an input voltage of the power converter. A pulse width of the PWM signal is correlated to an amplitude of the input voltage. The compensation circuit generates a current boost signal in response to the PWM signal by pushing up a peak value of a current-sense signal generated by a current-sense device in response to a primary-side switching current of the power transformer. A peak value of the current boost signal is adjusted by the pulse width of the PWM signal for compensating a difference of the maximum output power caused by the amplitude of the input voltage. | 11-27-2008 |
| 20080291700 | POWER CONVERTER HAVING PWM CONTROLLER FOR MAXIMUM OUTPUT POWER COMPENSATION - A PWM controller compensates a maximum output power of a power converter having a power switch. The PWM controller includes an oscillator for generating a saw signal and a pulse signal, a power limiter coupled to the oscillator for generating a saw-limited signal in response to the saw signal, and a PWM unit coupled to the power limiter and the oscillator to generate a PWM signal for controlling the power switch in response to the saw-limited signal and the pulse signal. The saw-limited signal has a level being flattened during a period of time before an output voltage is generated, and is then transformed to a saw-limited waveform after the period of time. | 11-27-2008 |
| 20080198636 | SWITCHING CONTROLLER FOR PARALLEL POWER SUPPLY - A switching controller for a parallel power supply is disclosed. The switching controller includes an input circuit coupled to an input terminal to receive an input signal for generating a phase-shift signal, a first integration circuit coupled to the input circuit to generate a first integration signal in response to a pulse width of the input signal, and a control circuit coupled to the first integration circuit to generate a switching signal for switching the power supply, the switching signal being enabled in response to the phase-shift signal, a pulse width of the switching signal being determined in accordance with the first integration signal. | 08-21-2008 |
| 20080197708 | SWITCHING CONTROLLER FOR POWER SHARING OF PARALLEL POWER SUPPLIES - A switching controller for power sharing of power supplies is disclosed. The switching controller includes an input circuit coupled to an input terminal to receive an input signal for generating a phase-shift signal, a first integration circuit coupled to the input circuit to generate a first integration signal in response to a pulse width of the input signal, and a control circuit coupled to the first integration circuit to generate a switching signal for switching the power supply, wherein the switching signal is enabled in response to the phase-shift signal, and a pulse width of the switching signal is determined in accordance with the first integration signal. | 08-21-2008 |
