| 摘要 |
An ignition circuit for a high intensity discharge (HID) lamp, comprising: first and second series coupled switching transistors connected across upper and lower voltage buses to which a source of DC voltage is connectable, the first switching transistor being connected from the second switching transistor at a common node to the upper voltage bus and the second switching transistor being connected from the common node to the lower voltage bus; a first capacitor connected, at one end, to the common node of the series coupled pair of switching transistors; a first diode having an anode connected to an opposite end of the first capacitor, and a cathode; a second capacitor coupled from the cathode of the first diode to the lower voltage bus; a second diode having an anode coupled to the upper voltage bus, and a cathode connected to the cathode of the first capacitor and the anode of the first diode; a spark gap having opposing ends and being coupled, at one end, to the cathode of the first diode; a pulse transformer having a primary winding coupled from the opposite end of the spark gap to the lower voltage bus and a secondary winding for connecting across the HID lamp; and a control circuit operable to alternatively turn on and off the first and second switching transistors, such that the spark gap is operable to deliver the pulse of current to the primary winding of the pulse transformer in synchronism with the turn on of the first switching transistor.
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