Detector circuit

Claim 1

A THRESHOLD CIRCUIT, INCLUDING, A SOURCE OF ALTERNATING SIGNALS, A UNI-JUNCTION TRANSISTOR HAVING A NORMAL HIGH IMPEDANCE CONDITION AND AN OPERATIVE LOW IMPEDANCE CONDITION, THE TRANSISTOR HAVING AN EMITTER, A FIRST BASE AND A SECOND BASE, MEANS OPERATIVELY COUPLED TO THE SOURCE AND RESPONSIVE TO THE ALTERNATING SIGNAL FROM THE SOURCE FOR RECTIFYING THE ALTERNATING SIGNAL, MEANS INCLUDING A PAIR OF RESISTORS CONNECTED BETWEEN THE FIRST AND SECOND BASES OF THE TRANSISTOR AND HAVING A COMMON CONNECTION AT THE EMITTER OF THE TRANSISTOR FOR INTRODUCING THE RECTIFIED VOLTAGE TO THE TRANSISTOR TO BIAS THE TRANSISTOR TO THE HIGH IMPEDANCE CONDITION, MEANS INCLUDING A ZENER DIODE CONNECTED BETWEEN THE FIRST AND SECOND BASES OF THE TRANSISTOR FOR REGULATING THE BIASING POTENTIAL INTRODUCED TO THE TRANSISTOR TO MAINTAIN THE BIASING POTENTIAL CONSTANT REGARDLESS OF CHANGES IN THE AMPLITUDE OF THE ALTERNATING SIGNAL, OPERATING MEANS COUPLED TO THE EMITTER OF THE TRANSISTOR FOR APPLYING THE ALTERNATING SIGNAL FROM THE SOURCE TO THE EMITTER TO OBTAIN AN OPERATION OF THE TRANSISTOR IN THE LOW IMPEDANCE CONDITION FOR ALTERNATING SIGNALS ABOVE A PARTICULAR AMPLITUDE, AND MEANS INCLUDING AN OUTPUT MEMBER RESPONSIVE TO THE OPERATION OF THE TRANSISTOR IN THE LOW IMPEDANCE CONDITION FOR PROVIDING AN OPERATION OF THE OUTPUT MEMBER.