Power supply circuit for car headlight discharge bulb - has micro-programmable unidirectional quasi-resonant switch with high voltage transformer producing smoothed output voltage

摘要

The supply circuit is connected to a car battery (1). The input is supplied to a transformer (3) in parallel with a quasi-resonant voltage switch (2). The switch (K1) is connected to a diode (D1) and a capacitor (C) and a command electrode (13) which are controlled by a pre-programmed microprocessor command circuit (10). The output current (11) in the discharge lamp circuit (9) is compared with the input current (14) in the microprocessor to smooth the current response, by adjusting the quasi-resonant voltage switch and main transformer switch (K2) operation. ADVANTAGE - Uses less primary current and avoids damaging transient phase current parasitics which can shorten component life.