The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 29, 1983
Filed:
Jun. 21, 1982
C Mills Edgar, Marietta, GA (US);
Solid State Systems, Inc., Marietta, GA (US);
Abstract
A bistable switch for controlling a latching relay for connecting and disconnecting an air conditioning load, operable over a telephone line by the application of a short burst of one of a pair of determined frequencies. The switch includes a power supply capacitor (35) charged directly from the telephone line (32, 33). A pair of narrow band filters (39, 40) each respond to one of the pair of frequencies. The output of each filter drives an FET amplifier (60) which in turn drives a charge pump (68, 69). When a sufficient amount of charge is received, the charge pump will provide a firing pulse to one of a pair of SCRs (77). The SCRs are each connected in one leg of a bridge circuit which includes one of a pair of diodes (79). The remaining legs of the bridge are formed by a pair of transistors (80) with the coil (46) of a bistable relay (47) attached across the bridge. The selective firing of one of the pairs of SCRs causes current to flow in one of the two possible directions (86, 87) through the coil either setting or resetting the relay.