Protection circuit for intrinsically safe electro-magnetic actuators and a protection circuit for intrinsically safe energy underground supply systems

摘要

The circuit has two short circuit units that are arranged separate from each other and are switched parallel to a coil of an electromagnetic actuator for short circuiting the coil during potential reversion of coil voltage. One of the unit has a short-circuit semiconductor switch (16) and a detecting circuit (30) to detect the potential reversion, where the switch is activated with the detecting circuit.