Control circuit for security fence electrification unit - has capacitor for switching two complementary transistors controlling triac, connected to contact breaker

摘要

The electronic unit is used for the electrification of a security fence around a field. It generates pulses of current without the use of any moving parts. The unit comprises a capacitor. The charge and discharge of the capacitor between two voltage levels switch two complementary transistors and the gate of a triac. The triac is initiated at zero voltage and is supplied by direct current in its passive state. The unit also has a self-checking circuit which trips a contact-breaker if the pulses are longer than a set duration. The circuit comprises another capacitor and a diac. If the duration of current through the diac is longer than the set duration, the diac allows a discharge of the capacitor and cut-off of the supply to the main circuit.