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:
Jul. 06, 1982
Filed:
Nov. 25, 1980
Gordon F Ehret, Alhambra, CA (US);
William N Rowley, Palos Verdes Estates, CA (US);
Richard E Mullen, Tustin, CA (US);
The Marley-Wylain Company, Mission Woods, KS (US);
Abstract
A liquid level presence detection circuit includes a selectively gatable TRIAC serially connected with a load and triggered into conduction by twin sensitive-gate SCR's connected anode-to-cathode with the gates of the SCR's connected to voltage divider circuits which provide gating current to the SCR's in response to the presence of a conductive liquid bridging the two spaced apart contacts of a liquid presence detecting probe. The circuit is used in wet-niche type lamp assemblies that provide underwater illumination in swimming pools and the like and in which cooling is effected by the surrounding liquid. The detection circuit advantageously interrupts the flow of electrical energy to the lamp when the level of surrounding liquid falls below a predetermined level to prevent over-temperature operation of the lamp and consequent damage thereto and resumes the flow of electrical energy to the lamp when the level of the surrounding liquid increases to a safe level to permit adequate cooling thereof.