Original Publication Date: 1979-Dec-31
Included in the Prior Art Database: 2004-Apr-02
Xerox Disclosure Journal
The figure shows the circuit diagram for a, relay tester which electronically identifies defective relays. A terminal 11 for receiving a single supply voltage is connected to the non-inverted input (+) of an operational amplifier 12 through a precision resistive voltage divider which is made of resistors 13 and 14. The contacts of the relay to be tested, generally indicated within the envelope 15, are wired in series and the single supply voltage is applied to the relay. The last contact in the series is connected to the inverted input terminal (-1 of the operational amplifier 12 through another precision resistive voltage divider which is made of resistors 16 and 17. Selection of the normally open position or normally closed position for the relay is accomplished by a hand operated switch 18. Switch 18 is connected to the supply voltage, and in closed position it supplies power to a relay coil 19.