Abstract: A ballast (10) for powering at least one gas discharge lamp (20) comprises a switching converter (100) and an inverter (900). Switching converter (100) includes a transistor (130) and a control circuit (200) that provides substantially zero voltage switching of the transistor (130) at a very high frequency. Preferably, control circuit (200) includes a drive circuit (300), a turn-on synchronization circuit (400), a current mirror circuit (500), a rail voltage regulator circuit (600), and a lamp current regulator circuit (700). Drive circuit (300) is preferably realized by a circuit arrangement that includes a standard pulse-width modulation integrated circuit (310).

Abstract: A high intensity discharge (HID) assembly comprises ballast circuits which includes a micro-controller, and an HID headlamp. In order to deter theft of the HID assembly from a vehicle, the micro-controller communicates with a vehicle computer, checks the VIN of the vehicle, and if the micro-controller does not recognize the VIN, causes the HID headlamp to operate in a flickering power output mode. The ballast circuits include a power control circuit, a lamp current regulator, a 400v regulator, a current sense circuit, a turn-on synchronization circuit, a shut down circuit, and a pulse width modulator.

Abstract: A circuit for operating a high intensity discharge (HID) lamp includes an H-bridge connected between a common terminal and a power line, and a control circuit connected to the H-bridge. The control circuit includes a transformer having a primary winding connected between the common terminal and a power terminal and a secondary winding connected between the common terminal and the power line, and a current sense resistor connected in series between the secondary winding and the common terminal. The HID lamp is connected to the common terminal and to the second winding so as sense a current across the current sense resistor.

Abstract: A circuit for operating a high intensity discharge (HID) lamp includes an H-bridge connected between a common terminal and a power line, and a control circuit connected to the H-bridge. A boost circuit is connected in parallel with the H-bridge between the power line and the common terminal, where the boost circuit includes a resistor, a Zener diode and a capacitor connected in series.

Abstract: A first vehicle lamp driver circuit for a light emitting diode (LED) array, the LED array having a first string of four LEDs in series and a second string of four LEDs in series. A first LED driver drives the first LED string and a second LED driver drives the second LED string. In a STOP mode of operation, the current to both LED strings is controlled by the LED driver in series with the LED string. In a TAIL mode of operation, the current is provided to only one LED string via a series connected diode and resistor. When there is reduced input voltage, operation of the LED strings is provided by switching circuits that short-out one LED in each LED string. A second vehicle lamp driver circuit comprises a first LED string and a second LED string in series with a control switch having a feedback circuit for maintaining constant current regulation to control the sum of the current in each LED string and reduce switching noise.