Power supply with integrated choke for generating and monitoring the ABB i-bus® system voltage. Bus connection via bus connection terminal. Up to 2 batteries can be connected to buffer the power supply in the event of a power failure. The battery is charged by the power supply during normal operation. With potential-free contact for fault reporting. The power supply has a wide-range input for the supply voltage in the range 85.265 V AC, 50/60 Hz.