Patent ID: 6291947
Filing Date: 2001-09-18
Classification: H05B,Y10S

Abstract:
Circuit arrangement for operating at least one discharge lamp, the circuit arrangement having the following features:a half-bridge inverter (T1, T2, A) having a drive apparatus (A) and having a downstream load circuit (LD, CR, j1, j2),at least one half-bridge capacitor (CK) connected to the load circuit and to the half-bridge inverter,the load circuit (LD, CR, j1, j2) having electrical connections (j1, j2) for at least one discharge lamp (LP), andmeans for monitoring the voltage drop across the at least one half-bridge capacitor (CK),characterized in that the means for monitoring the voltage drop across the half-bridge capacitor (CK):have a first RC element (R1, C1) and a second RC element (R2, C2), which are connected to one another by a threshold switch (DC),the first RC element (R1, C1) being connected to the center tap (M) of the half-bridge inverter (T1, T2, A), andthe second RC element (R2, C2) being connected to the half-bridge capacitor (CK), andhave means for detecting the switching state of the threshold switch (DC).