Liquid level detection circuit for control of liquid level responsive device
US4338546A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 25, 1980 |
| Grant date | Jul 6, 1982 |
| Priority date | — |
| Expiry date | Nov 25, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S367/908
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.