Communications: electrical – Condition responsive indicating system – Specific condition
Patent
1977-09-02
1979-07-31
Caldwell, Sr., John W.
Communications: electrical
Condition responsive indicating system
Specific condition
250381, 340506, G08B 1710
Patent
active
041632265
ABSTRACT:
Alarm condition detecting apparatus in the form of a combustion products detection system for monitoring a zone to detect the occurrence of fire therein. The apparatus has a plurality of detecting units adapted to be interconnected as parallel loads with a control unit. Each detecting unit receives operating power which may be from the control unit and functions to monitor a selected portion of the zone, generating, as appropriate, condition signals indicative of condition normal, impending alarm, alarm or unit malfunction. The impending alarm and unit malfunction signals are preferably pulsed signals of distinctly different frequencies and a light emitting diode (LED) arrangement is included in the detecting units to generate visual ouputs corresponding to the impending alarm, alarm and unit malfunction signals. The condition signals generated by the detecting units may be transmitted to and monitored by the control unit by the method of correspondingly changing the parallel load impedance thereacross to cause changes in a loop current flowing in the control unit. In response to such loop current changes, the control unit is adapted to appropriately indicate that the zone is in a normal state, an impending alarm condition, an alarm state, detecting unit malfunction or system trouble. To indicate alarm condition, the control unit latches in an alarm output state. The control unit has time delay circuitry to prevent latching into the alarm output state until an alarm condition signal of predetermined duration has been received.
REFERENCES:
patent: 3801972 (1974-04-01), Ho Kim et al.
patent: 3906474 (1975-09-01), Lehsten
patent: 4017852 (1977-04-01), Kabat
Caldwell Sr. John W.
Myer Daniel
Statitrol Division Emerson Electric Co.
Wymore Max L.
LandOfFree
Alarm condition detecting apparatus and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Alarm condition detecting apparatus and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Alarm condition detecting apparatus and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-24428