Patent ID: 7057358
Filing Date: 2006-06-06
Classification: H05B,Y02B

Abstract:
1. An electronic ballast, comprising: a DC voltage converter having a timing switch, for generating a regulated output DC voltage, and which can be fed from a DC voltage source; an inverter arranged to be fed from the output DC voltage of the DC voltage converter; and a regulation circuit to which are delivered a nominal value signal and an actual value signal corresponding to the output DC voltage of the DC converter, and which generates, as setting value signal, switch-on pulses for the timing switch, wherein the regulation circuit includes a first counter and a second counter, the first counter having a bit width at least equal to the bit width of the second counter, the first counter is one with reversible count direction, which counts in either direction in dependence upon whether the actual value signal is greater or smaller than the nominal value signal, a comparator is arranged to compare output signals of the two counters for obtaining the setting value signal, and a pulse width of the switch-on pulses for the timing switch is determined by a time period between a switch-on signal for the timing switch and a temporally following attainment of equality of count stages compared with one another, whereby at a switch-on time point of the timing switch the second counter carries out a new count procedure.