the power supply arrangement is designed such that during operation the current is distributed with high utilization of the power pack but without the power pack being overloaded as shown in fig1 the control units st 1 st 2 st n are connected to a common connection line 7 at intermediate potential for convenience a resistor 8 is connected between the lines 1 and 7 each control unit st 1 st 2 st n comprises among other things control means 9 such as a microcomputer microprocessor or an electronic evaluator as well as two controlled current sources 10 and 11 which are connected in parallel between the lines 2 and 7 and can consist of controlled transistors in addition each control unit is provided with a current measuring device 12 which measures the effectively consumed current of the associated control unit including any connected electric loads a control link between the device 12 and the current source 10 serves to adjust the latter as a function of a measured actual current value in the associated control unit the current measuring device 12 consequently adjusts the associated current source 10 to a current iq1 corresponding or proportional to the actual current in the supply line 1 a parameter which is representative of the effectively consumed currents in the control units st 1 st 2 st n therefore appears as a variable voltage on the common line 7 as the source parameters current and voltage of the constant voltage source are known and the common line 7 carries a load dependent voltage potential it is possible to determine the still available power of the constant voltage source.