A circuit arrangement for cable checking, cable testing, cable diagnosis and/or cable fault localization with
- a voltage source having a first voltage multiplier for a positive voltage and a second voltage multiplier for a negative voltage,
- current sources that are connected to one another in combination with the voltage multipliers to generate a test voltage over a load impedance of a cable to charge and discharge a load capacitance of the cable,
- a control device interconnected with the voltage source and the current sources, characterized in that
- the control device has a digital signal processor for regulating the test voltage over the load impedance of the cable measured via a voltage divider and for specifying a target value of the voltage source, and that the voltage multipliers are either connected to two main converters or are connected to both a main converter and an auxiliary converter generating a positive auxiliary voltage and a negative auxiliary voltage in such a way that either a positive voltage in accordance with the target-value specification and a constant, unregulated negative voltage, or a negative voltage in accordance with the target value specification and a constant, unregulated positive voltage, exist at the outputs of the voltage multipliers, wherein the respective unregulated voltage is either generated by the respective main converter or by the unregulated auxiliary converter and the voltage multipliers are interconnected to the current sources through a coupling diode in each case, so that a back-feed of the voltage multipliers is prevented, that the current sources connected with one another are connected via at least one protective resistor to the voltage divider and the cable, and that two reference potentials of the voltage multipliers connected with one another are connected via a measurement impedance adaptable to a measuring range to the reference potential of the cable, wherein the reference potentials of the voltage multipliers and the reference potential of the voltage divider are an auxiliary ground.