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. 21, 1981
Filed:
Feb. 12, 1980
Stanley E Hinshaw, Ponca City, OK (US);
Charles F Cole, Jr, Ponca City, OK (US);
Conoco, Inc., Ponca City, OK (US);
Abstract
A fluid level indicator circuit is used in cooperation with a probe attached to a long wire where the probe has first and second electrodes for contacting the surface of the fluid and leads communicating to the indicator circuit. The water level indicator has a low current high gain transistor and a power source which has sufficient potential to not only properly reverse bias the transistor when the probes are out of contact with the fluid but also properly forward bias when the probes are in contact with conductive fluid. A meter and current adjusting device are provided in series with a collector and emitter to provide an indicator when the probes are in or out of the water. The circuit also has a light to give a visual indication.