Testing circuit for vibration sensors in surveillance system - has system interrupting connection to symmetrical coupling and applying test voltage

摘要

The test circuit is used to check the working of one or more vibration sensors, used in an anti-intruder surveillance system, for stores factories etc. Each of the sensors (1) is connected via an electronic switch (2) and a symmetrical coupling (3) to an input amplifier (4), connected via a further switch (5) to an evaluating circuit (6). The test circuit (7,8) interrupts the connection between each sensor (1) and the symmetrical coupling (3) and delivers a test voltage to the sensor, with the connection between the sensor (1) and the coupling (3) then re-established. The subsequent induced voltages are then evaluated by the evaluation circuit (6).