| 摘要 |
PURPOSE: Provided is an operating device for providing as cost-effectively as possible a potential-free evaluation of the current through the resonance capacitor for the purpose of disconnecting in the event of filament breakage. CONSTITUTION: A load circuit comprising L31, Lp, C31 and R31 is connected to output terminals(J1,J2). The load circuit is designed as a series circuit of L31, the lamp(Lp) and R31. Only one terminal of the two filaments is used in each case in this series circuit for connection of the lamp(Lp). The C31 is connected in parallel with the lamp via the respective other terminal of the two filaments. The R31 serves to detect the load current. A voltage is tapped at the connecting point between(R31) and the lamp(Lp), and fed to the input(x) of an AC voltage generator(G3). This voltage is proportional to the load current. All the information required for determining the phase of the load current impedance(Z) is therefore available in the AC voltage generator(G3). The phase of the load current impedance(Z) is the difference between the phase of the output voltage at the output terminals(J1,J2) and the phase of the load circuit current. |
