Electrical circuit arrangements

Details Electrical circuit arrangements Electrical circuit arrangements

1984-10-30

1986-12-09

Rowland, James L.

Communications: electrical

Condition responsive indicating system

Specific condition

374184, 374170, G08B 1706, G01K 700

Patent

active

046283013

ABSTRACT:
A fire detecting arrangement has a longitudinal fire detector having conductors separated by a substance whose resistance decreases with temperature and whose charge acceptance capability increases with temperature. The detector is supplied with a rectangular waveform swinging between +5 and -5 volts through resistors, one of which is high compared with the other. High temperature will therefore cause a greater volt drop across the detector during positive waveform portions than during negative waveform portion, the potential division effect of the unequal resistors being enhanced by the increased charging current. Contamination or damage merely decreases the resistance of the detector and the lack of charging current means that the inequality of the voltage drops during positive and negative portions of the drive waveform is not so marked. A comparator compares the voltage across the detector with different reference levels at predetermined time instants synchronised with the drive waveform to produce digital signals which are fed to shift registers to cause a "fire" or "fault" warning to be produced.

REFERENCES:
patent: 3540041 (1970-11-01), Payne
patent: 4247848 (1981-01-01), Kitta et al.

Affiliated with

Also associated with

Rating

Electrical circuit arrangements does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Electrical circuit arrangements, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electrical circuit arrangements will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1387551