Grenergy Opto Inc.

Au Optronics Corporation

Jian-Shen Li

Yen-Ping Wang

Pei-Yuan Chen

Chia-Chieh Hung

Wei-Chuan Su

Ko-Ming Lin

Ya-Yun Yu

Yueh-bao Lee

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.

Electronic ballast with dimming control from power line sensing

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.

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.

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.

The present invention provides a DC to DC conversion circuit, comprising a DC power supply, a DC to DC converter, a power management IC and a load, wherein the load may be a backlight source of a liquid crystal display. The power management IC controls the DC to DC converter to convert a DC voltage supplied by the DC power supply to an output voltage of the DC to DC converter, which is supplied to the load. The power management IC is capable of controlling the DC to DC converter to adjust the output voltage to a minimum voltage actually needed by the load according to the variation of the minimum voltage which is actually needed by the load.

Growing community of inventors

Hsin-Chu, Taiwan

Jian-Shen Li