A method for operating at least one LED, and at least one fluorescent lamp using a circuit arrangement comprising an input having a first and a second input terminal for connecting an AC supply voltage;
- a main rectifier having a first and a second input terminal and a first and a second output terminal, wherein the first and the second input terminal of the main rectifier are coupled to the first and the second input terminal for connecting the AC supply voltage;
- an auxiliary rectifier having a first and a second input terminal and a first and a second output terminal, wherein the first and the second input terminal of the auxiliary rectifier are coupled to the first and the second input terminal for connecting the AC supply voltage;
- an inverter comprising at least one series circuit formed by a first and a second switch, wherein the series circuit is coupled to the first and the second output terminal of the main rectifier, and the output of said inverter having at least one terminal for connecting the fluorescent lamp, wherein the first and the second switch each have a control electrode, an operating electrode and a reference electrode;
- a starting device having a first and a second terminal, wherein its first terminal is coupled to a control electrode of one of the switches of the inverter;
- a pull-down circuit having a first and a second terminal, wherein its first terminal is coupled to the output of the inverter;
- a starting capacitor for providing energy for the starting device;
- wherein the second terminal of the starting device and the second terminal of the pull-down circuit are directly coupled to the first output terminal of the auxiliary rectifier;
- wherein the starting capacitor is directly coupled between the first and the second output terminal of the auxiliary rectifier;
- and wherein there is arranged in parallel with the starting capacitor a series circuit comprising a first and a second terminal for the at least one LED and an LED switch, wherein the LED switch has a control electrode, an operating electrode and a reference electrode, and a timer having a timer capacitor, wherein the input the timer is directly coupled to at least one of the first and the second input terminal of the input, and the first output terminal of which is directly coupled to the control electrode of the LED switch, and the second output terminal of which is directly coupled to the reference electrode of the LED switch;
- the method comprising:
- after the AC supply voltage has been applied:
- a1) charging the timer capacitor and the starting capacitor;
- a2) coupling the voltage dropped across the timer capacitor to the control electrode of the LED switch;
- a3) coupling the voltage dropped across the starting capacitor to the starting device;
- wherein the following is to be performed depending on the charge state of the starting capacitor:
- b1) if the charge state of the starting capacitor before AC supply voltage was applied was below a predefineable limit value:
- switching on the LED switch and thus switching on the at least one LED without triggering the starting device;
- b2) if the charge state of the starting capacitor before the AC supply voltage was applied was above a predefineable limit value:
- triggering the starting device and thus switching on the fluorescent lamp with LED switch switched off and thus at least one LED switched off.