Signal light control and function monitoring circuit - uses test voltage applied across transducer supplying signal lamp function monitor.

摘要

The control and function monitoring circuit uses a controlled switch (S2) associated with the individual signal lamps (SL1) for each signal light for short-circuiting the primary winding of an isolating transformer (T2), with a second controlled switch (S3) applying a test voltage (UPR) across the primary of a transducer (W) inserted in the lamp current circuit. The transducer provides an operating voltage for a signal lamp function monitor, with a fuse in the lamp circuit responding to an overcurrent for irreversible disconnection of the circuit. Pref. the test voltage (UPR) is obtained from the secondary winding (W1.3) of a supply transformer (T1) supplying the isolating transformer. USE/ADVANTAGE - For light signals controlled from remote central point. No special switching unit required.