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:
Feb. 08, 1977
Filed:
Dec. 29, 1975
Michael D Hollabaugh, San Jose, CA (US);
Clemar Manufacturing Corporation, Azusa, CA (US);
Abstract
Apparatus for the control of a number of remotely located irrigation or sprinkler valves from a central location by means of control signals encoded onto a single pair of power transmission lines linking a central encoder and a number of remote decoders. The encoder includes a multiplexer for selecting on/off signals supplied by a controller, an address generator to drive the multiplexer and to generate decoder addresses for transmission, and coupling circuitry to encode the generated decoder addresses and on/off signals onto an alternating-current power signal, by clipping half-portions of the signal to represent zero values. Each decoder includes a bridge rectifier, from which clock pulses and a serial data stream are derived. The data stream is continually shifted through a shift register, and a comparator compares a decoder address field in the register with the conditions of a set of manual switches indicative of the decoder address. When the comparator finds a match, the on/off signal is gated into a flip-flop and utilized to generate a valve control signal.