| 摘要 |
<p>An electronic ballast includes a triggered boost circuit (Q1, Q2), a driven inverter (Q5, Q6, and a low voltage signal generator (71) in a half-bridge, push-pull, series resonant, parallel loaded configuration. The boost circuit is triggered by a voltage (A) from the inverter and the inverter is controlled by the signal generator. The boost circuit includes a low voltage output (B) for powering the signal generator. In the event of a fault, the operation of the signal generator is interrupted, thereby shutting off the boost circuit and the inverter. A DC blocking capacitor (95) is in series with the lamps and a resistor (101) is connected in parallel with the DC blocking capacitor. The ballast is started by a pulse of displacement current through the lamp filaments to the boost circuit. Since the lamp filaments must be intact, the ballast does not begin a lamp starting sequence until lamps are connected to the ballast.</p> |
