Protection device for protecting automation device e.g. field bus coupler, against overvoltage in e.g. vehicle engineering, has limiting units limiting voltage at input of supply unit during exceeding limit value of supply voltage

摘要

The device (1) has a power supply unit (3) supplying voltage to an automation device (4). Voltage monitoring units (2, 2') determine supply voltage at an output of the power supply unit and compare the supply voltage with permissible overvoltage limit values and voltage limiting units (5, 5'). The limiting units are coupled to an input of the power supply unit. The limiting units limit the voltage at the input of the power supply unit when an overvoltage limit value of the supply voltage at the output of the power supply unit exceeds.