Abstract: A power converter circuit for a low power illumination device includes a boost converter circuit, a buck converter circuit, and a control circuit. The control circuit configures the boost converter circuit to alternately operate in a current conducting mode and an off mode, to draw different values of the current from an electric transformer in different periods in the current conducting mode, and to stop drawing current from the electric transformer in the off mode. The control circuit further configures the buck converter circuit to generate the required output signals to the low power illumination device according to the output of the boost converter circuit so that the low power illumination device may function normally.

Abstract: A power converter circuit of a low power illumination device includes a boost converter circuit, a buck converter circuit, and a control circuit, for cooperating with a dimmer and an electric transformer. The control circuit configures the boost converter circuit to alternatively operate in a current conducting mode and an off mode, to draw current from the electric transformer in the current conducting mode, and to stop drawing current from the electric transformer in the off mode. The control circuit further configures the buck converter circuit to generate the required output signals to the low power illumination device according to the configuration of the dimmer so that the low power illumination device may perform the required dimming function.

Abstract: The present invention discloses a light emitting device power supply circuit, a light emitting device driver circuit and a control method thereof. The light emitting device driver circuit is coupled to a tri-electrode AC switch (TRIAC) dimmer circuit, and it controls the brightness of a light emitting device circuit according a rectified dimming signal. The light emitting device driver circuit includes a power stage circuit and a light emitting device control circuit. The light emitting device control circuit generates a switch control signal. The power stage circuit operates at least one power switch thereof according to the switch control signal to generate a latching current for firing the TRIAC dimmer circuit, and the latching current is inputted to the light emitting device circuit.

Abstract: The present invention discloses a control circuit and a control method of a light emitting device circuit. When the light emitting device circuit is normally connected in normal operation, an output current is regulated to a predetermined current. When the light emitting device circuit is removed, an output voltage is regulated to a predetermined voltage. When the light emitting device circuit is reconnected, the output current is regulated to the predetermined current. The output voltage is at or above a level when the light emitting device circuit is normally connected in normal operation, and the predetermined voltage is lower than this level.

Abstract: The present invention discloses an active bleeder circuit capable of triggering a tri-electrode AC switch (TRIAC) circuit in all phase. The active bleeder circuit receives a rectified signal having an OFF phase and an ON phase. The active bleeder includes: a detection circuit for generating a detection signal according to the rectified signal and accumulating the detection signal in the OFF phase of the rectified signal; and a current sinker circuit coupled to the detection circuit, for generates a latching current to trigger the TRIAC circuit by operating a switch when the detection signal exceeds a predetermined level. The present invention also discloses a light emitting device power supply circuit and a TRIAC control method using the active bleeder circuit.

Abstract: The present invention discloses a switching regulator and a control circuit and a control method thereof. The switching regulator generates a compensation signal according to a feedback signal, and generates a driving signal according to the compensation signal, to control a power stage for converting an input voltage to an output voltage. The compensation signal is adjusted according to the input voltage, such that when the input voltage is equal to or lower than a predetermined level, the compensation signal is kept at a predetermined value.

Abstract: A gas-discharge lamp controller utilizing a novel preheating phase control mechanism, having: a supply voltage tracking reference voltages generator, biased between a supply voltage and a reference ground, for generating a first reference voltage which is proportional to the supply voltage; and a control unit, for generating a high threshold signal according to the first reference voltage and a saw-tooth signal, the peak value of the saw-tooth signal being proportional to the supply voltage, wherein the control unit has a preheating phase, the high threshold signal is coupled with the first reference voltage during the preheating phase, and the time duration of the preheating phase is set by a predetermined number of periods of the saw-tooth signal.

Abstract: 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.

Abstract: The present invention discloses a light emitting device power supply circuit, a light emitting device driver circuit and a control method thereof. The light emitting device driver circuit is coupled to a tri-electrode AC switch (TRIAC) dimmer circuit, and it controls the brightness of a light emitting device circuit according a rectified dimming signal. The light emitting device driver circuit includes a power stage circuit and a light emitting device control circuit. The light emitting device control circuit generates a switch control signal. The power stage circuit operates at least one power switch thereof according to the switch control signal to generate a latching current for firing the TRIAC dimmer circuit, and the latching current is inputted to the light emitting device circuit.

Abstract: The present invention discloses an electronic ballast with dimming control from power line sensing for a fluorescent lamp, comprising: a control voltage generator, used to generate a control voltage according to a switching count of a power line; an oscillator, used to generate an oscillating signal, wherein the oscillating signal is of a fixed frequency and has a rising voltage portion and a falling voltage portion; and a comparator, used to generate a high side gating signal according to voltage comparison of the oscillating signal and the control voltage.

Abstract: A gas-discharge lamp controller utilizing a novel preheating phase control mechanism, having: a supply voltage tracking reference voltages generator, biased between a supply voltage and a reference ground, for generating a first reference voltage which is proportional to the supply voltage; and a control unit, for generating a high threshold signal according to the first reference voltage and a saw-tooth signal, the peak value of the saw-tooth signal being proportional to the supply voltage, wherein the control unit has a preheating phase, the high threshold signal is coupled with the first reference voltage during the preheating phase, and the time duration of the preheating phase is set by a predetermined number of periods of the saw-tooth signal.

Abstract: The present invention discloses a single chip ballast controller, capable of providing brightness levels overview and brightness setting of a fluorescent lamp during power-on period, having: a switching detection circuit, used to generate a set signal, which changes from an inactive state to an active state when a supply voltage falls below a threshold voltage; a time-varying reference voltage generator, used to generate a time-varying reference voltage varying between a first level and a second level during a power-on period, wherein the time-varying reference voltage can be fixed at a level by the active state of the set signal during the power-on period; and a gating signal generator, used to generate a high side driving signal and a low side driving signal according to an error voltage between the time-varying reference voltage and a current sensing voltage.

Abstract: The present invention discloses an electronic ballast with dimming control from power line sensing for a fluorescent lamp, comprising: a line switching sensing circuit, used to generate a switching sensing signal by performing a voltage comparison operation on a DC voltage, and generate a reset signal according to the off time of the power line; a control voltage generator, used to generate a control voltage according to the count of said switching sensing signal; a voltage controlled oscillator, used to generate an oscillating signal according to the control voltage; and a non-overlapping driver, used to generate a high side driving signal and a low side driving signal according to the oscillating signal.

Abstract: The present invention discloses an electronic ballast with dimming control from power line sensing for a fluorescent lamp, comprising: a line switching sensing circuit, used to generate a switching sensing signal by performing a voltage comparison operation on a DC voltage; an oscillating signal gating unit, used to gate an oscillating signal with a pulse signal to generate a gated oscillating signal, wherein the pulse width of the pulse signal is generated according to the switching sensing signal; and a non-overlapping driver, used to generate a high side driving signal and a low side driving signal according to the gated oscillating signal.

Abstract: The present invention discloses an electronic ballast with dimming control from power line sensing for a fluorescent lamp, comprising: a line switching sensing circuit, used to generate a switching sensing signal by performing a voltage comparison operation on a DC voltage, and generate a reset signal according to the off time of the power line; a dimming voltage generator, used to generate a dimming voltage according to a count of the switching sensing signal; and a phase-controlled non-overlapping driver, used to generate a high side driving signal and a low side driving signal for delivering a lamp current according to the dimming voltage, wherein the dimming voltage is used to generate a phase, and the phase is used to generate the lamp current.

Abstract: The present invention relates a single chip ballast controller for step-dimming of a fluorescent lamp, comprising: a counting circuit, used to generate a switching count by counting the instances where the supply voltage falls below a threshold voltage; a reference voltage generator, used to generate a reference voltage proportional to the switching count; and a gating signal generator, used to generate a high side driving signal and a low side driving signal according to an error voltage between the reference voltage and a current sensing voltage to regulate the current sensing voltage at the reference voltage, wherein the current sensing voltage is proportional to a lamp current flowing through the fluorescent lamp.

Abstract: The present invention discloses an electronic ballast with dimming control from power line sensing for a fluorescent lamp, comprising: a control voltage generator, used to generate a control voltage according to a switching count of a power line; an oscillator, used to generate an oscillating signal, wherein the oscillating signal is of a fixed frequency and has a rising voltage portion and a falling voltage portion; and a comparator, used to generate a high side gating signal according to voltage comparison of the oscillating signal and the control voltage.

Abstract: This patent discloses a differential type level shifter, comprising: a differential pair of transistors, having a pair of gate terminals, a pair of drain terminals and a common source terminal, with the pair of gate terminals coupled to a first clock signal and a second clock signal; a current source, coupled between the common source terminal and a reference ground, used to provide a bias current; and a pair of loading resistors, having a common end and a pair of output ends, with the common end coupled to a power line, the pair of output ends coupled to the pair of drain terminals; wherein the pair of drain terminals are used to generate a set signal and a reset signal in response to the first clock signal and the second clock signal.

Abstract: The present invention discloses an electronic ballast with dimming control from power line sensing for a fluorescent lamp, comprising: a line switching sensing circuit, used to generate a switching sensing signal by performing a voltage comparison operation on a DC voltage, and generate a reset signal according to the off time of the power line; a dimming voltage generator, used to generate a dimming voltage according to a count of the switching sensing signal; and a phase-controlled non-overlapping driver, used to generate a high side driving signal and a low side driving signal for delivering a lamp current according to the dimming voltage, wherein the dimming voltage is used to generate a phase, and the phase is used to generate the lamp current.

Abstract: The present invention discloses an electronic ballast with dimming control from power line sensing for a fluorescent lamp, comprising: a line switching sensing circuit, used to generate a switching sensing signal by performing a voltage comparison operation on a DC voltage; an oscillating signal gating unit, used to gate an oscillating signal with a pulse signal to generate a gated oscillating signal, wherein the pulse width of the pulse signal is generated according to the switching sensing signal; and a non-overlapping driver, used to generate a high side driving signal and a low side driving signal according to the gated oscillating signal.