Patent ID: 6381551
Filing Date: 2002-04-30
Classification: H05B,Y02B

Abstract:
Method for providing an output signal (Ua) having a desired value of a characteristic quantity (Uarms) at an output of a switched-mode power supply unit, where at least one low-voltage lamp is connected to the output of the switched-mode power supply unit, a load current (IL) corresponds to a sum of the currents (I1, I2) flowing through all the low-voltage lamps, on an input side the switched-mode power supply unit is driven by an input signal (Uel, Ue2) having at least one variable characteristic quantity (PW), and the switched-mode power supply unit is connected to an operating voltage (UB), having the following steps:a. in a calibration operation: a1. determination of the dependence of the characteristic quantity (Uarms) of the output signal (Ua) on the operating voltage (UB), the load current (IL) and at least one variable characteristic quantity (PW) of the input signal (Ue1, Ue2); a2. storage of the dependence determined in step a1) in a memory; b. during operation: b1. determination of characteristic quantities of the load current (IL) and of the operating voltage (UB); b2. reading of a value or values of the at least one variable characteristic quantity (PW) of the input signal (Ue1, Ue2) in dependence on the values of load current (IL)and operating voltage (UB) determined in step b1) from the memory, which correspond to the desired value of the characteristic quantity (Uarms) of the output signal (Ua); and b3. varying of the at least one variable characteristic quantity (PW) of the input signal (Ue1, Ue2) to the value(s) read from the memory in step b2).