Patent application number | Description | Published |
20090279214 | PROTECTION APPARATUS AND METHOD FOR A POWER CONVERTER - A power converter uses a PWM controller to provide a driver output to modulate the duty of the power converter. A protection apparatus and method compare a current sense input of the PWM controller with a reference voltage to assert a signal representing failure, count the number of cycles where the signal representing failure is asserted, and reset an enable signal to inhibit the driver output if the signal representing failure is asserted in several cycles. | 11-12-2009 |
20100315843 | METHOD OF DETECTION FOR OUTPUT SHORT CIRCUIT OF A FLYBACK POWER SUPPLY - Disclosed are methods of detection for output short circuit of a flyback power supply, which detect the current sense signal provided by a current sense resistor serially connected to a power switch of the flyback power supply, and thus quickly identify whether or not the flyback power supply suffers output short circuit. | 12-16-2010 |
20100320989 | PROTECTION APPARATUS AND METHOD FOR AN ISOLATED TYPE POWER SUPPLY - An isolated type power supply includes a transformer, and a power switch and a current sense resistor serially connected to a primary coil of the transformer, and a protection apparatus and method monitor a control signal which is used to switch the power switch in normal operation, and trigger a signal to stop the power from switching when the control signal becomes greater than a threshold. This protection apparatus and method can more quickly detect short circuit of the current sense resistor, and prevent the isolated type power supply from overcurrent impact. | 12-23-2010 |
20110051463 | APPARATUS AND METHOD FOR STANDBY POWER REDUCTION OF A FLYBACK POWER CONVERTER - An apparatus and method for a flyback power converter reduce the standby output voltage of the flyback power converter by switching the reference voltage provided by a shunt regulator of the flyback power converter or the ratio of voltage divider resistors of the shunt regulator, to reduce the standby power consumption by an output feedback circuit of the flyback power converter, the shunt regulator, and the voltage divider resistors, and thereby the power loss of the flyback power converter in standby mode. | 03-03-2011 |
20110249476 | VOLTAGE DETECTOR AND PROTECTION APPARATUS USING THE SAME - A voltage detector includes a zener diode having a cathode connected to a detect terminal of the voltage detector, a junction field effect transistor having an input terminal connected to an anode of the zener diode, and a resistor connected between an output terminal and a control terminal of the junction field effect transistor. When the voltage on the detect terminal is higher than the breakdown voltage of the zener diode, the junction field effect transistor produces a current flowing through the resistor, and thereby a detection signal can be obtained from the voltage across the resistor. | 10-13-2011 |
20120086480 | CIRCUIT AND METHOD FOR SUB-HARMONIC ELIMINATION OF A POWER CONVERTER - A circuit and method are provided for a power converter to select one from a plurality of current limit signals as a final current limit signal according to the present duty ratio of a power switch for the pulse width modulation of the next cycle, so that the duty ratio of the power switch in the next cycle is prevented from acute variation to eliminate sub-harmonic which otherwise may happen. | 04-12-2012 |
20120194162 | PULSE WIDTH MODULATION CONTROLLER AND METHOD FOR OUTPUT RIPPLE REDUCTION OF A JITTERING FREQUENCY SWITCHING POWER SUPPLY - A pulse width modulation controller and method for output ripple reduction of a jittering frequency switching power supply detect the current of a power switch of the switching power supply to generate a current sense signal, and adjust the gain or the level of the current sense signal according to the switching frequency of the power switch to adjust the on time of the power switch, to reduce the output ripple of the switching power supply caused by the jittering frequency of the switching power supply. | 08-02-2012 |
20120194227 | JITTERING FREQUENCY CONTROL CIRCUIT AND METHOD FOR A SWITCHING MODE POWER SUPPLY - A jittering frequency control circuit and method for a switching mode power supply enlarge the uttering frequency range of the switching frequency of the switching mode power supply when the switching mode power supplier enters a frequency reduction mode, to improve the electro-magnetic interference of the switching mode power supply operating with the frequency reduction mode. | 08-02-2012 |