Easy to install temperature alarm system

• US 5,917,416 A
• Filed: 03/11/1997
• Issued: 06/29/1999
• Est. Priority Date: 03/11/1997
• Status: Expired due to Fees

• Current Assignee: Robert Michael Read
• Original Assignee: Robert Michael Read
• Inventors: Read, Robert Michael
• Primary Examiner(s): Hofsass, Jeffery A.
• Assistant Examiner(s): TRIEU, VAN THANH
• Application Number:
  US08/821,967
• Time in Patent Office: 840 Days
• Field of Search: 340/585, 340/588, 340/589, 340/691, 340/584, 165/48.1, 165/254, 137/78.3, 137/624.11, 320/2, 320/39
• US Class Current: 340/584
• CPC Class Codes: G01K 3/005 Circuits arrangements for indicating a predetermined temperature fire detection G08B17/00

Abstract

A temperature alarm system includes a temperature sensing module and an alarm circuit that are powered by a photocell and a battery that is charged by the photocell. The photocell normally provides enough power to operate the system and charge the battery. When the temperature sensing module senses a temperature that exceeds a predetermined alarm limit, it generates an alarm signal which activates an alarm circuit that generates a visual and/or audible alarm either immediately after the alarm signal is generated, or after the alarm signal has been generated for a period of time. The generation of the alarm signal and/or the alarm causes the system power consumption to increase, so the system begins to draw power from the battery. After the alarm condition is corrected, the system returns to normal power consumption, and the photocell provides enough power to operate the system and charge the battery.

Claims

1. An easy-to-install temperature alarm system comprising:

a temperature sensing module that generates an alarm signal when it senses a predetermined temperature;

a temperature sensing device coupled to the temperature sensing module through a cable, whereby the temperature sensing device can be positioned in a monitored space remote from the temperature sensing module;

an alarm coupled to the temperature sensing module for receiving the alarm signal, the alarm generating a warning responsive to the alarm signal;

a photocell coupled to the temperature sensing module for providing electric power to the module;

a housing;

a first battery coupled to the temperature sensing module to provide a first power supply voltage to the temperature sensing module; and

a second battery connected in series with the first battery, and coupled to the alarm to provide a second power supply voltage to the alarm;

wherein the temperature sensing module, the alarm, and the photocell are disposed within the housing to provide a compact, self-contained unit that can be mounted in a convenient, occupied location, thereby eliminating power supply wiring and simplifying installation.

2. An easy-to-install temperature alarm system comprising:

a temperature sensing module that generates an alarm signal when it senses a predetermined temperature;

a temperature sensing device coupled to the temperature sensing module through a cable, whereby the temperature sensing device can be positioned in a monitored space remote from the temperature sensing module;

an alarm coupled to the temperature sensing module for receiving the alarm signal, the alarm generating a warning responsive to the alarm signal;

a photocell coupled to the temperature sensing module for providing electric power to the module; and

a housing;

wherein the temperature sensing module, the alarm, and the photocell are disposed within the housing to provide a compact, self-contained unit that can be mounted in a convenient, occupied location, thereby eliminating power supply wiring and simplifying installation;

wherein the system has a charge rate of power consumption and an alarm rate of power consumption that is higher than the charge rate of power consumption, and the photocell has a power generating capacity sufficient to provide at least the charge rate of power consumption; and

wherein the alarm includes an indicator for generating the warning and support circuitry for the indicator, and the alarm is adapted such that the indicator and its support circuitry are only enabled when the alarm signal is generated, thereby reducing power consumption when the alarm signal is not generated.

3. A system according to claim 2 wherein the support circuitry includes a counter.

4. A system according to claim 2 wherein the indicator is a visual indicator.

5. A system according to claim 2 wherein the indicator is an audible indicator.

6. An easy-to-install temperature alarm system comprising:

a temperature sensing module having an output terminal, the temperature sensing module generating an alarm signal at the output terminal when a predetermined temperature is sensed;

a temperature sensing device coupled to the temperature sensing module through a cable, whereby the temperature sensing device can be positioned in a monitored space remote from the temperature sensing module;

an alarm having an input terminal connected to the output terminal of the temperature sensing module, the alarm generating a warning responsive to the alarm signal;

a first battery coupled to the temperature sensing module to provide a first power supply voltage to the temperature sensing module;

a second battery connected in series with the first battery, and coupled to the alarm to provide a second power supply voltage to the alarm;

a photocell connected to the batteries to charge the batteries; and

a housing;

wherein the temperature sensing module, the alarm, the batteries, and the photocell are disposed within the housing to provide a compact, self-contained unit that can be mounted in a convenient, occupied location, thereby eliminating power supply wiring and simplifying installation.

7. A method of monitoring a temperature in an enclosed space comprising the steps of:

providing a temperature sensing module, an alarm, and a photocell in a housing as a compact, self-contained unit;

mounting the housing in an occupied location remote from the enclosed space;

mounting a temperature sensing device in the enclosed space;

coupling the temperature sensing device to the temperature sensing module through a cable;

converting ambient light into electric power using the photocell;

storing the electric power in a first battery and a second battery connected in series with the first battery;

supplying electric power from the first battery to the temperature sensing module;

detecting the temperature using the temperature sensing module; and

generating a warning with an alarm circuit at the occupied location if the detected temperature violates a temperature threshold;

wherein generating a warning includes supplying electric power from the second battery to the alarm circuit if the detected temperature violates the temperature threshold.