| 摘要 |
The invention relates to a circuit arrangement for operating LEDs (LED1, LED2, LED3) with a pulsating DC voltage. Said circuit arrangement has a constant power source which prevents the brightness of the LEDs following the pulse form of the DC voltage. Said circuit arrangement is also provided with an auxiliary power source which takes over the supply of power to the LEDs when the pulsating DC voltage falls below a predefined minimum value in the interpulse periods and the constant power source is inactive. The pulsating DC voltage is generated from an AC voltage, preferably from an AC power supply system voltage, by means of a bridge rectifier. If the circuit arrangement is intended to be operated with an upstream phase-gating dimmer, the circuit arrangement can additionally be provided with an extinction circuit which, in the event of a drop in the input voltage caused by the interpulse periods, briefly reduces the input resistance of the circuit arrangement to such an extent that a sufficiently high extinction current can flow across the input resistor. |
