Power limiting device for electrical device operated in explosive region, has input clip pair for applying supply voltage, and thyristor connected in short-circuit line, where thyristor has gate connected with node of bridge circuit

摘要

The device has an input clip pair (1, 2) for applying a supply voltage, and a fuse (F) for limiting current and arranged according to the pair. A Zener diode (Z) is provided for voltage limitation of the supply voltage, and a thyristor (T) is connected in a short-circuit line. The thyristor has a gate that is connected with a node of a bridge circuit such that the thyristor is ignited, when voltage corresponding to maximum allowable current is applied to a resistor or voltage exceeding the Zener voltage is applied to the Zener diode. The bridge circuit is connected in parallel to a load (Rl).