Power line signal system having a relay controlled indicator at the receiver

Claim 1

A RECEIVER FOR UTILIZING HIGH FREQUENCY SIGNALS RECEIVED OVER A NORMALLY LOW FREQUENCY WIRING SYSTEM WHICH COMPRISES: CONNECTING MEANS ADAPTED TO CONNECT SAID RECEIVER TO SAID WIRING SYSTEM; A PRIMARY WINDING IN ELECTRICAL SERIES RELATIONSHIP WITH SAID CONNECTING MEANS TO BE ENERGIZED THEREFROM; A BLOCKING CAPACITOR IN ELECTRICAL SERIES RELATIONSHIP WITH BOTH OF SAID CONNECTING MEANS AND SAID PRIMARY WINDING THE PASS SAID HIGH FREQUENCY SIGNALS AND BLOCK PASSAGE OF LOW FREQUENCY CURRENT; A SECONDARY WINDING A FLUX-LINKING RELATIONSHIP WITH SAID PRIMARY WINDING; A VOLTAGE DOUBLING CIRCUIT ENERGIZED BY SAID SECONDARY WINDING AND ADATPED TO PROVIDE A RECTIFIED OUTPUT VOLTAGE EXCEEDING THE EFFECTIVE VOLTAGE FROM SAID SECONDARY WINDING; AN AMPLIFIER IN AMPLIFYING RELATIONSHIP TO SAID RECTIFIED OUTPUT VOLTAGE TO PRODUCE AN AMPLIFIED VOLTAGE THEREFROM; A FIRST RELAY COIL IN ENERGIZABLE RELATIONSHIP FROM SAID AMPLIFIED VOLTAGE, FIRST RELAY CONTACTS ADAPTED TO CLOSE UPON ENERGIZATION OF SAID FIRST RELAY COIL; A SECOND RELAY COIL IN SERIES WITH SAID FIRST CONTACTS AND ADAPTED TO BE ENERGIZED FROM SAID LOW FREQUENCY WIRING SYSTEM; SECOND RELAY CONTACTS ADAPTED TO CLOSE UPON ENERGIZATION OF SAID SECOND RELAY COIL; AND INDICATING MEANS IN SERIES WITH SAID SECOND CONTACTS AND ADAPTED TO BE ENERGIZED FROM SAID LOW FREQUENCY WIRING SYSTEM.