A circuit 3, wherein {HEAD ~ the alarm circuit} includes {TAIL ~ a light emitting diode} which produces a visible warning of switch failure when the alarm switching transistor is turned on 
A circuit 3 , wherein { HEAD ~ the alarm circuit } includes { TAIL ~ a light emitting diode } which produces a visible warning of switch failure when the alarm switching transistor is turned on
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH