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:
Mar. 22, 1983
Filed:
Feb. 26, 1981
David R Thompson, Ladybank, GB;
Pico Electronics Limited, Glenrothes, GB;
Abstract
The switching circuit couples an appliance (1) to a power main (LN) via remotely controllable switching means (2) and is operable to change the state of the switching means (2) in response to a manual double switching of the appliance power switch so that the appliance can be manually switched ON after it has been remotely switched OFF. A capacitor (CAP1) generates from the mains voltage an alternating current signal of a phase differing from that of the mains voltage by an amount dependent on the external impedance across the output. The switching circuit monitors this phase difference and changes the state of the switching means (2) if it detects two phase difference changes exceeding a predetermined value in opposite senses within a predetermined time period, this being indicative of a manual double switching of the appliance power switch. The switching circuit does not operate spuriously for thermostatically controlled appliances nor in response to noise spikes.