| 摘要 |
Connected to a mains rectifier is a return mains (6) for adjustment of the lamp current, and for feeding it back to the feed side. The rectifier comprises a rectifying part and a smoothing part (5), to which the return mains is coupled. The return mains comprises a diode-capacitor network (D5-D8, C6, C7, C9, C10). The alternating rectifier comprises two transistors connected in series between the outputs of the mains rectifier, which conduct alternately and via the connecting point of which the lamp is fed with current. - With the base emitter circuit of each transistor is connected in parallel a series circuit of a coil and a parallel circuit of a capacitor, a resistor and a series circuit of a second coil, a diode and a resistor. The coils constitute secondary coils in a transformer, the primary coil of which is fed by the lamp current. A start unit is connected to the mains rectifier, and comprises two series-coupled resistors, from the connecting point of which an ignition voltage pulse is taken via a diode. A diode-thyristor is coupled between the base of a transistor and the connecting point between the series circuit capacitor and a resistor. |
