Abstract: A power factor correction device comprises a power stage circuit converting input alternating current voltage into input current according to a pulse width modulation signal and outputs the input current to a load generating output voltage on the load, and sampling the input current outputting a correcting current; a current compensating circuit receiving and comparing the correcting current with a reference current signal generating a compensating current signal; a voltage compensating circuit receiving and comparing the output voltage with a reference voltage generating a compensating voltage signal; a multiplication amplifier receiving the compensating current signal and the compensating voltage signal generating an updated reference current signal by multiplying the compensating current signal with the compensating voltage signal; and a pulse width modulation converter receiving the compensating current signal and the compensating voltage signal generating the pulse width modulation signal to synchronize

Abstract: In an interleaving power factor corrector, a control device interleavingly drives first and second converting circuits such that the power factor corrector generates a voltage output (Vo), and includes first and second control modules generating respectively first and second driving signals (Q_master, Q_slave) that correspond respectively to first and second control signals for controlling operations of power switches of the first and second converting circuits. A phase modulating module generates a reset signal (S_PTCL) based on an inverted first driving signal (Qn_master) and a feedback compensation signal (Vcomp) outputted by the first control module, and a reset signal (S_syn) outputted by the second control module. When one of the reset signals (S_syn, S_PTCL) has a predetermined level, the second driving signal (Q_slave) has a level for switching the power switch of the second converting circuit to an OFF-mode.

Abstract: In an interleaving power factor corrector, a control device interleavingly drives first and second converting circuits such that the power factor corrector generates a voltage output (Vo), and includes first and second control modules generating respectively first and second driving signals (Q_master, Q_slave) that correspond respectively to first and second control signals for controlling operations of power switches of the first and second converting circuits. A phase modulating module generates a reset signal (S_PTCL) based on an inverted first driving signal (Qn_master) and a feedback compensation signal (Vcomp) outputted by the first control module, and a reset signal (S_syn) outputted by the second control module. When one of the reset signals (S_syn, S_PTCL) has a predetermined level, the second driving signal (Q_slave) has a level for switching the power switch of the second converting circuit to an OFF-mode.

Abstract: A single-stage power factor correction circuit includes a first rectifier, a second rectifier, a full bridge rectifier, a capacitor, a fly back transformer, and a switch. Unlike conventional single-stage power factor correction circuits, the present invention just needs to pass through two rectifiers at positive and negative half cycles, so as to reduce the conduction loss, lower the temperature of the power supply, and control the voltage of the control energy storage capacitor, and stabilize voltage output.

Abstract: A preheat control device for modulating the voltage of a gas-discharge lamp is disclosed, which comprises: a pulse-width modulation (PWM) circuit, for controlling the voltage of the gas-discharge lamp while it is operating at a preheat state; a pulse frequency modulation (PFM) circuit, for controlling the frequency of the gas-discharge lamp while it is operating at a steady state so as to stabilize the current flowing through the lamp; and a timing unit, for determining a preheat period of the gas-discharge lamp.

Abstract: An active clamp switching circuit includes a transformer having a primary winding and a secondary winding, a first switch, a capacitor, an impedance device, a second switch and a rectifier. The capacitor, the impedance device and the second switch form a reset loop for the primary winding so that the impedance device lowers the electric current going through the second switch, preventing burnout of the second switch.

Abstract: A single-stage power factor correction circuit includes a first rectifier, a second rectifier, a full bridge rectifier, a capacitor, a fly back transformer, and a switch. Unlike conventional single-stage power factor correction circuits, the present invention just needs to pass through two rectifiers at positive and negative half cycles, so as to reduce the conduction loss, lower the temperature of the power supply, and control the voltage of the control energy storage capacitor, and stabilize voltage output.

Abstract: A preheat control device for modulating the voltage of a gas-discharge lamp is disclosed, which comprises: a pulse-width modulation (PWM) circuit, for controlling the voltage of the gas-discharge lamp while it is operating at a preheat state; a pulse frequency modulation (PFM) circuit, for controlling the frequency of the gas-discharge lamp while it is operating at a steady state so as to stabilize the current flowing through the lamp; and a timing unit, for determining a preheat period of the gas-discharge lamp.

Abstract: A LED illuminating module is provided. A plurality of LEDs are directly disposed on a circuit board to thin out the whole module and minimize its volume. A problem that the circuit board of the conventional LED illuminating module and a board provided with the LEDs are separate is resolved.