Communications: electrical – Condition responsive indicating system – Specific condition
Patent
1982-12-30
1985-09-03
Rowland, James L.
Communications: electrical
Condition responsive indicating system
Specific condition
340640, 307350, G08B 2100
Patent
active
045395624
ABSTRACT:
Current provided to a generally constant impedance load is monitored to detect a predetermined load current decrease not resulting from normal load voltage fluctuations, such decrease indicating an abnormal increase in load impedance. A latching alarm is actuated when the predetermined load current decrease is detected. The degree of load current decrease tolerable without activating the alarm is determined by a user-adjustable percentage-of-change sensitivity control. A logic gate blocks alarm functions when the load current decreases to an abnormally low level. The disclosed device can be used to monitor the status of a line voltage energized heat trace cable constituted by a plurality of parallel-connected resistance wire heating elements. Multiple monitoring devices can be used in conjunction with a master alarm which can be reset without resetting the particular monitoring device alarm that triggered the master alarm.
REFERENCES:
patent: 2449739 (1948-09-01), Duttera
patent: 2912622 (1959-11-01), Warrington
patent: 3934239 (1976-01-01), Mason et al.
patent: 4203095 (1980-05-01), Wilson, Jr.
patent: 4389640 (1983-06-01), Dawdy
patent: 4421976 (1983-12-01), Jurek
Rowland James L.
The Scott & Fetzer Company
Tumm Brian R.
LandOfFree
Load current monitoring device for detecting predetermined degre does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Load current monitoring device for detecting predetermined degre, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Load current monitoring device for detecting predetermined degre will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-616229