Electrical fault protection circuit for connection to a dc voltage source and a fault-sensitive electronic unit drawing voltage from it with start/stop input

摘要

Electrical fault protection circuit for connection to a voltage source S and a fault-sensitive microcomputer drawing voltage E1 from it with a start/stop input. The circuit has an RC circuit R3, C2 with a capacitor C2, whose voltage E2 is applied to the microcomputer's start/stop input for starting, stopping, and restarting of the microcomputer. In parallel with this capacitor C2 is connected a thyristor Ty, which is controlled by a transistor Tr, which detects variations in the voltage E1 from the voltage source. In event of fault or interruption of this voltage, the thyristor Ty is switched on, so that the capacitor C2 quickly discharges and the voltage E2 across it drops within 1 ms to the level at which the microcomputer is shut off. This eliminates the risk of the information stored in the microcomputer being lost as a result of faults or interruption in the voltage. IMAGE