Apparatus including a fire sensor and a non-fire sensor

• US 5,659,292 A
• Filed: 02/21/1995
• Issued: 08/19/1997
• Est. Priority Date: 02/21/1995
• Status: Expired due to Term

• Current Assignee: Pittway Corporation (Honeywell International Inc.)
• Original Assignee: Pittway Corporation (Honeywell International Inc.)
• Inventors: Tice, Lee D.
• Primary Examiner(s): Swarthout, Brent A.
• Assistant Examiner(s): Pope, Daryl C.
• Application Number:
  US08/391,208
• Time in Patent Office: 910 Days
• Field of Search: 340/506, 340/517, 340/577, 340/521, 340/522, 340/523, 340/526, 340/527, 340/532, 340/825.06, 340/825.16, 340/293, 340/286.05
• US Class Current: 340/522
• CPC Class Codes: G08B 29/183 Single detectors using dual technologies G08B13/1672, G08B13/2448, G08B13/2494 take precedence

Abstract

Outputs from a smoke detector and non-fire sensors such as temperature and humidity can be combined to produce a delay in a signal from the smoke sensor indicative of a potential fire condition. The signals can be combined locally and all of the sensors can be carried in a single housing. Alternately, the sensors can be carried in separate housings and combined at a remote control panel. The value output from the humidity and temperature sensor can be used in determining whether or not to produce a delay. Alternately, the rate of change of either or both parameters can be used to determine whether a delay is necessary.

Claims

1. A fire detector comprising:

a housing;

a fire sensor carried by said housing wherein said sensor produces a fire related electrical signal indicative of a sensed fire condition;

another sensor carded by said housing wherein said another sensor produces an electrical output indicative of a different sensed ambient condition;

control circuitry carried by said housing and coupled to said sensors wherein said control circuitry determines a rate of change of said electrical output and blocks said fire related electrical signal for a predetermined period of time when said rate of change exceeds a preset value.

2. A detector as in claim 1 which includes a second sensor different from said another sensor, carried by said housing wherein said second sensor is coupled to said control circuitry and produces a second electrical output indicative of a second sensed ambient condition, wherein said control circuitry determines a rate of change of said second electrical output.

3. A detector as in claim 1 wherein said another sensor includes a humidity sensor.

4. A detector as in claim 2 wherein said second sensor includes a temperature sensor.

5. A fire detection system comprising:

a fire sensor wherein said sensor produces a fire related electrical signal indicative of sensed fire condition;

another sensor wherein said another sensor produces an electrical output indicative of a different sensed ambient condition;

control circuitry coupled to said sensors wherein said control circuitry determines a rate of change of said electrical output and blocks said fire related electrical signal for a predetermined period of time when said rate of change exceeds a preset value.

6. A detection system as in claim 5 wherein said another sensor includes a temperature sensor.

7. A detection system as in claim 5 wherein said another sensor includes a humidity sensor.

8. A detection system as in claim 5 which includes a communications link which extends between said control circuitry and said sensors.