An arrangement includes a conductor, forming the primary side of a transformer, the secondary side being connected to a rectifier circuit. The rectifier output is connected to a voltage stabilizing circuit for an electronic unit and to a first series circuit formed by a first switching component and a first resistor. In the event of a first voltage value being reached at the first input of the voltage stabilizing circuit, the first switching component is switched to be conductive. The secondary current of the transformer flows via the first resistor to drop an electrical voltage across the first resistor. The electric current of conductor is determinable from the voltage. The use of just one transformer used both for energy generation and for current measurement makes it possible to realize a very compact and small design of a current measuring device having a simple construction.