Communications: electrical – Condition responsive indicating system – Specific condition
Patent
1996-12-18
1998-11-17
Hofsass, Jeffery A.
Communications: electrical
Condition responsive indicating system
Specific condition
73304C, 324658, 324663, G08B 2100
Patent
active
058382410
ABSTRACT:
A level detector circuit for detecting a level of immersion of an elongated probe within a liquid. The level detection circuit includes a first set of transistors. One of these transistors charges an elongated probe and a second charges a capacitor. A reference current source provides a reference current based on the charging current provided to the elongated probe by the first transistor and an additional transistor which also charges the probe at a rate such that the voltage on the capacitor and the probe are maintained the same. A monitoring circuit develops an analog level signal based on the current provided by the reference current source. This analog level signal is converted by the combination of an analog to digital circuit and a microprocessor for providing a pulse frequency modulated communications signal corresponding to the analog level signal which in turn is related to the length of the probe immersed within the liquid.
REFERENCES:
patent: 4145619 (1979-03-01), Tseng
patent: 4224606 (1980-09-01), Bartles
patent: 4676100 (1987-06-01), Eichberger
patent: 5042299 (1991-08-01), Wells
patent: 5073757 (1991-12-01), George
patent: 5121632 (1992-06-01), Keeler et al.
patent: 5406843 (1995-04-01), Hannan et al.
patent: 5446444 (1995-08-01), Lease
patent: 5463378 (1995-10-01), Gibb
Lease Benjamin N.
Pierson Otis P.
Hofsass Jeffery A.
Robertshaw Controls Company
Tweel , Jr. John
LandOfFree
Liquid level transmitter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Liquid level transmitter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Liquid level transmitter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-888227