| 摘要 |
An electronic ballast for at least one low-pressure discharge lamp contains an inverter which is connected to a direct-voltage source (UBUS), a load circuit which is connected to the inverter and contains the lamp (LA) and a series resonant circuit, and an evaluating circuit arrangement (M1) which reacts to different operating states of the lamp (LA) and in the case of a defect or removal of the lamp (LA) generates corresponding signals for switching off the inverter. A heating transformer, for heating the coils (W1, W2), the primary winding (Tp) of which is connected in series with a switch (S3) to the output of the inverter and in any case is connected to the direct-voltage source (UBUS) if the inverter is switched off on account of the heating-coil defect or the removal of the lamp (LA), with the switch (S3) being clocked in this off-phase. |
