Circuit arrangement for the DC supply of a load

摘要

A circuit arrangement is described for the DC supply of a load from an AC network. In the case of a circuit arrangement for the DC supply of a load in which the pulsating DC voltage at the output of a network rectifier circuit can fluctuate within wide limits, in order to achieve a constant load voltage and continuous absorption of a sinusoidal current from the network by using the current absorbed from the network as a control variable, with simple circuit and control complexity, it is provided that a first input (D), to which a variable which is proportional to the input voltage of a blocking converter is applied, of a control circuit (9) is connected via a first logic circuit (13-15) for forming the nominal value of the input current of the blocking converter, to a first input of a comparator circuit (17) to whose second input a variable is applied which is derived especially from the actual value of the input current of the blocking converter, and whose output (C) is connected to a control circuit (19) for the controlled switching stage (5) of the blocking converter, the second input (B), to which a variable which is proportional to the actual value of the output voltage is applied, of the control device (9) being connected to a first input of a second logic circuit (12) to which the nominal value of the output voltage is applied at a second input, and which second logic circuit (12) forms a correction variable which is dependent on the difference value and is supplied to the first logic circuit (13-15) in order to form the nominal value of the input current, the nominal current value being changed as a function of the correction variable in the sense of reducing the error in the output voltage. <IMAGE>