Communications: electrical – Continuously variable indicating – With meter reading
Patent
1989-11-24
1991-02-26
Yusko, Donald J.
Communications: electrical
Continuously variable indicating
With meter reading
3408253, 34082572, 361172, H04Q 100, G06F 1520
Patent
active
049965255
ABSTRACT:
An electronics lockout circuit including an antenna adapted to receive ra frequency signals from a transmitter, and a radio frequency detector circuit which converts the radio frequency signals into a first direct current voltage indicative of the relative strength of the field resulting from the radio frequency signals. The first direct current voltage is supplied to a trigger circuit which compares this direct current voltage to an adjustable direct current reference voltage and provides a second direct current voltage at the output thereof whenever the amplitude of the first direct current voltage exceeds the amplitude of the reference voltage. The second direct current voltage provided by the comparator circuit is supplied to a disconnect relay circuit which upon receiving a signal from the electronic control unit of an electronic combination lock during the time period the second direct current voltage is present isolates the door strike coil of a security door from the electronic control unit. This prevents signals falsely generated by the electronic control unit because of radio frequency signals in the vicinity of the electronic control unit from energizing the door strike coil and thereby accidentally opening a security door.
REFERENCES:
patent: 2787731 (1957-04-01), Wetzger
patent: 2909769 (1959-10-01), Spaulding
patent: 3564501 (1971-02-01), Flook, Jr.
patent: 3621335 (1971-11-01), Coleman
patent: 3671816 (1972-06-01), Ritzow
patent: 3851227 (1974-11-01), Hedin
patent: 4196347 (1980-05-01), Hadley
patent: 4408251 (1983-10-01), Kaplan
patent: 4621258 (1986-11-01), Campman
patent: 4744021 (1988-05-01), Kristy
Becker, Jr. Earl M.
Miller Allen
Holloway III Edwin C.
Kalmbaugh David S.
The United States of America as represented by the Secretary of
Yusko Donald J.
LandOfFree
R. F. lockout circuit for electronic locking system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with R. F. lockout circuit for electronic locking system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and R. F. lockout circuit for electronic locking system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-295986