Alarm systems

• US 3,388,389 A
• Filed: 06/09/1964
• Issued: 06/11/1968
• Est. Priority Date: 06/09/1964
• Status: Expired due to Term

• Current Assignee: Lance L. Henriques
• Original Assignee: Lance L. Henriques
• Inventors: Henriques, Lance L.
• Application Number:
  US04/373,728
• Time in Patent Office: 1,463 Days
• US Class Current: 340/530
• CPC Class Codes: G08B 25/06 using power transmission lines

Claims

1. A CARRIER-CURRENT ALARM SYSTEM FOR COOPERATION WITH A SOURCE OF ALTERNATING CURRENT AND WITH AN ELECTRICALPOWER TRANSMISSION LINE, SAID SYSTEM COMPRISING:

AT LEAST ONE LAMP CONNECTED IN CIRCUIT WITH SAID SOURCE AND HAVING A NORMALLY ILLUMINATED STATE CASTING A BEAM INTERRUPTABLE TO INITIATE AN ALARM;

A RECTIFYING CIRCUIT HAVING AN INPUT CONNECTED IN SERIES WITH SAID LAMP AND SAID SOURCE AND ENERGIZABLE BY THE LATTER, SAID RECTIFYING CIRCUIT FURTHER HAVING A DIRECT-CURRENT OUTPUT;

A SOLID-STATE CONTROLLED RECTIFIER IN SERIES WITH SAID OUTPUT OF SAID RECTIFYING CIRCUIT WHEREBY BURNOUT OF SAID LAMP RENDERS SAID CONTROLLED RECTIFIER NONCONDUCTIVE SAID CONTROLLED RECTIFIER HAVING A GATE, AN ANODE AND A CATHODE;

A PHOTOELECTRIC CELL IN THE PATH OF SAID BEAM HAVING A RELATIVELY CONDUCTIVE STATE UPON ILLUMINATION THEREBY, SAID PHOTOELECTRIC CELL BEING CONNECTED IN SERIES WITH SAID GATE AND BETWEEN SAID GATE AND SAID ANODE WHEREBY SAID GATE IS DISCONNECTED FROM SAID ANODE UPON INTERRUPTION OF SAID BEAM TO RENDER SAID CONTROLLED RECTIFIER CONDUCTIVE;

RESETTING-SWITCH MEANS CONNECTED ACROSS SAID ANODE AND SAID CATHODE OF SAID CONTROLLED RECTIFER FOR QUENCHING SAME AFTER IMPINGMENT OF SAID BEAM UPON SAID PHOTOELECTRIC CELL HAS BEEN RESTORED;