GB2434019A

GB2434019A - Temperature alarm with time delay able to warn of open widows or doors

Info

Publication number: GB2434019A
Application number: GB0624754A
Authority: GB
Inventors: Mervyn Porter
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-12-12
Filing date: 2006-12-12
Publication date: 2007-07-11
Anticipated expiration: 2026-12-12
Also published as: GB0624754D0; WO2008071942A1; GB2434019B

Abstract

An indoor living space ambient temperature sensitive alarm system is able to detect relative temperature rise or fall and is arranged so that an alarm signal is only triggered after a delay period has lapsed and the temperature is found to be still dropping or rising. Figure 1 shows an example alarm circuit with thermistor sensor 3 feeding an operational amplifier which differentiates the input signal over a delay period set by RC pair 5, 6. The system may be a stand alone unit (fig 2, not shown) or may comprise remote sensors mounted on doors or windows (figs 3-6, not shown). The system may trigger a door bell sounder to play a particular chime as an alarm. The system may also log occurrences of alarm events.

Description

1 2434019 -1-Temperature Sensitive Alarm System * Fiekiof the Invention

*:: The present invention relates to temperature sensitive alarm systems and in particular to: ....

systems for detecting open entrances and windows in a building. : *: Review of Art known to the Applicant 20.:.

The closest art known to the Applicant is a system which notifies the householder of the arrival of a visitor. The system comprises a Radio Frequency (RF) door-push and RF remote door-sounder. A visitor would depress the RF door-push, which would transmit a RF message to the RF remote door-sounder, which would activate an audible aLarm to attract the householder's attention.

This visitor arrival system does not inform the householder when a door or window is Left open. It does not inform the householder when a door has not been fully closed and becomes ajar. The visitor arrival system does not monitor the air temperature within a room, for temperature fluctuations originating from an open door and br window. The visitor arrival system does not have a dedicated message, or ring tone, for informing the householder that a door and/or window are open and that heat is being lost or gained.

Summary of the Invention

In its broadest independent aspect, the invention provides an indoor living space ambient temperature sensitive alarm system comprising: * means for generating an alarm; * means for detecting a drop or a rise in ambient temperature; * means for delaying the triggering of the generation of said alarm for a period; and * means for triggering the generation of said alarm if at the end of the period the temperature is still dropping or rising. * *

This configuration is particularly advantageous because it senses the temperature of the air * * * in an enclosed environment. The system can determine whether the temperature of the air is rising or fatLing. If the temperature is rising, it is indicative of heat building up within an enclosed area which incorporates closed doors and windows. The closed doors and/or * S * windows prevent any heat from escaping and therefore contribute to the build up of heat within the enclosed area. Heat loss would be due to heat escaping the enclosed area via open doors and/or windows. Furthermore, the advantage of the system's temperature * . **, 5.

sensing delay is that it ignores all the sensed temperature deviations within the temperature sensor's delay period. Therefore, it will not generate a false alarm when it senses a draft, when a person opens and shuts the door behind them, when they enter the enclosed area. A false alarm may also be generated when a user opens a window briefly and shuts it in the enclosed area. The system would generate an alarm, when the temperature is dropping continually faster than a known rate of change, over a period of time. The rate of the temperature drop over a period of time is indicative of a door and/or window being open.

Another advantage of this configuration is that it generates an alarm, which may be audible and/or visual. The alarm wilL inform the system users that a door and/or window is open. The alarm will stop when the user closes the open door and/or window, which stabilises the air temperature in the enclosed area, and stops the air temperature from falling or rising continually. The alarm may also be manually reset. This invention contributes to maintaining efficiency in heating an enclosed area, and also contributing to the security of an enclosed area by preventing unauthorised access, which may be invited by an open door or window.

In a subsidiary aspect in accordance with the invention's broadest independent aspect, said system incorporates an interface which communicates with a door chime equipped with at least one speaker and the means for generating an alarm employ said speaker.

This configuration is particularLy advantageous because the system would interface with a door-chime equipped system which incorporates at least one speaker. This eliminates the requirements for separate systems, one for the door arrival and one for door and/or window open, by integrating the two systems. This reduces the amount of equipment required to generate an audible alarm from at least one speaker. * * a.... *

In a further subsidiary aspect said door chime incorporates a number of different pre-* . : recorded chimes, at least one being predetermined for signalling the dropping or rising of S...' the ambient temperature. S. * * . S * *5

This configuration is particuLarly advantageous because the system wouLd sound a pre-* S recorded chime, which has been predetermined for informing the householder that the *SSS temperature is dropping due to a door and/or a window being open. *, : The system would also sound a pre-recorded chime, which has been predetermined for informing the householder that the temperature is rising, due to a door and/or window being open and losing cold air, which increases the cost for refrigeration and/or air conditioning.

In a further subsidiary aspect, the components are provided in a single walt-mountable unit.

This configuration is particularly advantageous because the system may be incorporated into one unit, which reduces the equipment requirements. This avoids installing separate independent boxes. The system can be utilised without the need for interfacing with other door arrival systems and operating fully in a self-contained unit. The system can be located virtually on any interior wall without the (imitations of transmission range which are inherent within a RF door arrival system.

In a further subsidiary aspect, the components are at Least in part built-in on the inside of a door and/or window.

This configuration is particularly advantageous because the system cannot be identified separately from a door and/or window. This eliminates the need to install independent sensor boxes locally to the intended door and/or window.

This is aLso advantageous because housing the sensor as near as possible to the door and/or window aperture, the temperature sensing response wilt be more sensitive and * * faster in responding to temperature drops and increases, which are caused by an open door * **.

and/or window. * * : * S S. * S. In a further subsidiary aspect, the system incorporates a storage medium which logs the occurrences of alarms, arid means are provided to allow the Logged information to be assessed by a user. * *.*. S...

This configuration is particularly advantageous because the system will be able to notify.* * the householder which doors and/or windows have been left open. This will aid the householder in trying to minimise utility costs, such as heating. If heating costs increase unexplainabty, this may be due to a door and/or window, which may have been left open repeatedly. This invention is also advantageous if the householder is undergoing a security investigation; an alarm activation may be Logged and gives an accurate time to any security infringements, i.e. a forced door and/or smashed window.

In a further subsidiary aspect, the system further comprises means for actuating the closure of a door or window if a predetermined period is exceeded.

This configuration is particularly advantageous because the system will interface with a door and/or window management system. When the system detects that a door and/or window has been left open, for a period greater than the predetermined period, the system will communicate with the and/or window management system to initiate the automatic closure of the open door and/or window.

Brief Description of the Figures

Figure 1 shows the circuit diagram required for a door and/or window open sensor.

Figure 2 shows a front view of an enclosure incorporating a temperature sensor and an audible warning device.

Figure 3 shows the constituent parts of a door and/or window open radio frequency (RF) system. *

Figure 4 shows a temperature sensing and audible warning unit in typicaL operation. * * * ...** Figure 5 shows the constituent parts of a door and/or window open RF system in typical :. . operation. * *.. *

Figure 6 shows an embedded temperature sensor embedded within a door/window frame. * . . 20..

Detailed Description of the Figures

Figure 1 shows a circuit diagram for a temperature sensing device, constructed from analogue electronic components. The circuit comprises an active high pass filter, a 211d order "Bessel" High Pass Filter with unity gain" 1 (already known) and a Voltage Divider 2 (already known). Alternatively, other configurations of active or passive high pass fiLters may be used, a typicaL alternative would be a "Butterworth" active high pass filter.

The Voltage Divider 2 comprises a thermistor 3 and a resistor 4. The thermistor is a temperature-sensing device, which has a resistance that decreases as the temperature rises. These devices are called negative temperature coefficients or NTC thermistors. This is indicated by the -t indicator next to the circuit symbol The Voltage Divider 2 is configured with the thermistor 3 connected to the bottom of resistor 4. This configuration increases the signal voltage at connection node 5 on the diagram when the thermistor 3 senses a temperature drop. If the thermistor senses a temperature increase, the voltage at connection node 5 drops. This Voltage Divider s characteristic is modelled by determining: / Thermistor 3 resistance Vout= ( ) X Vin \mermistor 3 resistance + Resistor 4/ The signal voltage at connection node 5, which is directly proportional to the temperature sen5ecl by the therniistor 3, is applied to the "2nd Order BesseL High Pass Filter with unity gain" 1, which is also connected to connection note 5. The 2 Order BesseL High Pass * Fitter with unity gain 1 comprises two sets of resistor-capacitor pairs. The first resistor-capacitor pair 5 comprises of resistor 6 and capacitor 7. The second resistor-capacitor pair 8 comprises of resistor 9 and capacitor 10. The 2d order filter has an improved frequency:. * role off characteristic of 12 DB/per octave (already known), which improves the filters functional response to a varying signaL voltage (already known). * .** * . . * *

The 2nd Order Filter characteristic is modelled by determining: (Transfer Function Capacitor 7 = ( \ 2rFcoR6 /Transfer Function Capacitor 10 ( 2tFcoR9 Transfer Function = A mathematical statement which details the relationship between the filter input and output.

Fco = The filter's Cut Off Frequency.

The 2' Order Bessel High Pass Filter monitors the voltage levels at the non-inverting input 11 and inverting input 12. The 2nd Order Bessel High Pass Fitter wilt produce an output voltage at connection node 63, when the voltage Level of the non-inverting input 11 differentiates more than a predetermined amount over a set time period. The set time period is determined by resistor -capacitor pair 5 and characterised by: Time period = ______________________ (Resistor 6 X Capacitor 7) The output voltage at connection node 63 will be used to activate further extraneous electronic circuitry to process an alarm signal, which may be transmitted to an audible

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device. This may be typically a full wave rectifier, which will activate a dedicated relay or further secondary circuitry, when the output voltage at connection node 63 drops. The full wave rectifier will also activate a dedicated relay or further secondary circuitry, when the *, Is output voltage at connection node 63 rises. *

For example, if the signal voltage monitored at non inverting input 11 of the operational amplifier 13, differentiates from the inverting input 12 by a predetermined amount, which is directly proportional to a temperature drop of two or more degrees Celsius, at thermistor 3, over a time period determined by resistor -capacitor pair 5. An output voltage at connection node 63 will occur, which will activate further electronic circuitry to produce a temperature drop alarm.

/ Voltage differential I -(Predetermined) \ out (Temperature drop alarm) = __________________________ Set time period / Voltage differential -Vout (Temperature drop alarm) = ( Proportional to >2 C Seconds or / Voltage differential -I Proportional to >4 C Vout (Temperature drop alarm) = _________________________ Seconds Figure 2 shows a single unit embodiment 15. of a living space ambient temperature sensitive alarm system".

This embodiment comprises a rectangular enclosure 16, which incorporates two rectangular front panels. A leftmost front panel 17 and a rightmost front panel 18, which are positioned vertically on the front plane. The leftmost panel 17 is shown to be adjacent to the rightmost panel 18, along its rightmost vertical edge 19. An elliptical temperature sensor 20, typically of a thermistor type, is mounted substantially vertical and centrally in the upper portion of panel 17. A rectangular audible device 21, typically a speaker, is mounted substantially central in the rightmost front panel 18.

The temperature sensor 15 monitors the air temperature about the unit's enclosure 16. If the air temperature deviates by more than a predetermined amount, over a period of time, the electronics contained within the enclosure 16, wiLl activate the audible device 21.

This embodiment is capable of being mounted directly onto a vertical surface, typically an interior waLl or frame.

This embodiment encapsulates all the system components and functionality within one unit.

This embodiment may incorporate a radio frequency (RF) means of communication to an independent receiver / chime unit.

Figure 3 shows a multiple unit embodiment 22, of the "living space ambient temperature sensitive alarm System".

This embodiment comprises a rectangular sensor unit 23. a rectanguLar battery RF receiver/chime unit 24 and mains-powered RF receiver/chime units 25.

The sensor unit 23 incorporates an elLiptical temperature sensor 26, typically of a thermistor type, and is mounted substantially vertical and centrally in the upper portion of the front panel 28. The front panel 28 is positioned vertically on the front plane. A rectangular RF transmitter 27 is mounted substantially vertical and central in the lower portion of panel 28.

The battery powered RF receiver/chime unit 24 incorporates a rectangular front panel 29.

The front panel 29 is positioned vertically on the front plane and substantially central along axis AA. The front panel 29 incorporates a rectangular light emitting diode (LED) 30, which is mounted substantially horizontal and centrally in the upper portion of the front * panel 29. A rectangular audible device 31, typically a speaker, is mounted in the lower * * portion of the front panel 29 and substantially ahgned with the front panel's 29 bottom right corner. S. * * *5

The mains-powered RF receiver/chime units 25 incorporate two front paneLs 32 and 33, which are Located vertically on the front plane. Panel 32 is positioned vertically aligned *...

with paneL 33 along axis BB. The front panel 32 incorporates a substantially vertical, .. : convexed. surface 35 along axis BB. A circular audible device 34, typicalLy a speaker, is mounted substantially central on the front panel 32. Front panel 33 incorporates three rectangular sockets 36, 37 and 38, which are configured to form a mains electricity supply socket. Socket 36 is located vertically in the upper portion of panel 33 and substantially central along axis CC. Sockets 37 and 38 are evenly spaced and located horizontally about the panel's 33 centre, aLong axis CC. The mains-powered RF receiver/chime units 25 incorporates three pins 39 and 40 (third pin not shown) which are mounted perpendicular to the rear panel (not shown). The three pins 39 and 40 (third pin not shown) are mounted in a configuration in which pin 39 is located vertically in the lower portion of the rear panel and substantially central aLong axis CC. Pins 40 (third pin not shown) are evenly spaced and located horizontalLy about the panel's centre, along axis CC.

The sensor unit 23 monitors the air temperature around the unit's enclosure. If the air temperature deviates by more than a predetermined amount, over a period of time, the electronics contained within the enclosure 41, wiLl activate and drive the RF transmitter 27 to transmit a "temperature drop" alarm message to the battery-powered and/or mains-powered receiver/chime units 24 and 25 respectively. The battery-powered and/or mains-powered (RF) receiver/chime units 24 and 25 will receive the "temperature drop" message transmitted from the sensor unit 23. Once the "temperature drop" message has been received, the electronics contained within the battery-powered RF receiver/chime unit 24 will activate and drive the audible device 31.

The mains-powered RF receiver/chime units are powered from mains electricity, via the three mains pins 39 and 41 (third pin not shown). Once the unit is connected into the electricity mains supply the system user may still have access to the mains electricity supply, via the mains socket 36, 37 and 38 which are mounted on the unit's front panel 33.

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Both the battery-powered and mains-powered (Rf) receiver/chime units may be used in conjunction with a temperature sensing unit 23, which increases the functional operation *5*I** range of the system.

The LED 30 located on the battery-powered RF receiver/chime unit, is used to indicate that the battery is powering the unit and/or also to indicate if a "temperature drop" message S...

has been received. : Figure 4 shows a single unit embodiment 42 of the invention, which is located in close proximity to a door aperture 43 and a window aperture 44. The door aperture 43 shows a door 45, which is not closed. The window aperture 44 shows a window 46, which is not closed. The single unit embodiment of the invention 42, will sense temperature deviations within a heated room, caused by a door and/or window which has been recently left open, and will therefore activate a self-contained alarm. The alarm wilt alert users that heat is escaping, a heated area, through an open door and/or window.

Figure 5 shows a multiple unit embodiment of the invention, which incorporates a remote sensor unit 47, a RF signal booster unit 57, battery-powered RF receiver/chime units 55 and mains-powered RF receiver/chime units 56.

The remote sensor unit 47 is located in close proximity to a door aperture 51 and a window aperture 52. The door aperture 51 shows a door 53 which is not closed. The window aperture 52 shows a window 54, which is not closed. The remote sensor 47 wiLl sense temperature deviations within a heated room caused by a door 53 and/or window 54, which has been teft open recently, and will therefore activate an alarm. The alarm activation will generate a "temperature drop" warning message, which will then be transmitted by a RF transmitting device to another independent unit. This unit may be a RF booster unit 57, which would be required, if the sensor unit 47 was out of communication range of a battery-powered and/or mains-powered RF receiver/chime unit 55 and 56 respectively. The booster unit would accomplish this by receiving a temperature drop" warning message at the limit of the temperature sensor's transmission range and then retransmitting the "temperature drop" warning message at full power, which may double the normal operating range of the remote sensor unit 47. The RF booster unit 57 is shown to be boosting the "temperature drop" warning message from a * remote sensor unit 47 to an array of independent, battery-powered or mains-powered. RF receiver/chime units 55 and 56 respectiveLy.

The RF communication range between the temperature sensor unit and the RF receiver/chime units may be substantially increased. This may result with the RF " * *** receiver/chime unit's audible effectiveness being reduced, when the user distances..

themselves from the RF receiver/chime unit. By incorporating more than one RF receiver/chime unit, the audible effectiveness to the user is maintained, by reducing the distance between the user and any one RF receiver / chime unit.

The multiple unit embodiment may incorporate more than one sensor unit. Therefore, if a large area is to be monitored, it may be divided up into individual zones. Each zone will incorporate a dedicated sensor unit, which will give the monitoring system the zone location that has been activated. This enables quick and decisive action in response to any alarm from the system in tracking and closing any open doors and/windows.

Figure 6 shows the top left hand corner of a typical door/window frame 62, which is incorporated in a door or window 58. The frame 62 may incorporate an embedded sensor unit 59, which incorporates an elliptical shaped temperature sensor 60 and RF transmitter 61. The temperature sensor unit 59 is therefore contained within the door/window frame 62 and eLiminates the need for an externally mounted sensor unit. Each frame which incorporates an embedded temperature sensor may be regarded as a zone. Therefore, the system will inform the user which door or window is open by determining which sensor-zone has generated the alarm.

The temperature sensing system may be installed in any heated room like an environmental chamber I room, domestic interior Living space, commercial interior working space, restaurant and other eateries and typically any enclosed heated, space. Therefore monitoring the enclosed air temperature for temperature deviations caused by open doors and/or windows.

The temperature sensing system may be externally installed to any enclosed, chilled, cold and frozen space. Therefore monitoring the outside air temperature for temperature -S..

deviations caused by open doors and windows. * . : * S *****.

The temperature sensor units may be interfaced with a door and/or window management system, which wilt automatically close open doors and/or windows. This may be * S. * accomplished through remote actuators attached to doors and windows. * ** S... S...

The scope of the invention is defined in the following claims. *. :

Claims

CLAIMS

1. An indoor living space ambient temperature sensitive alarm system comprising: * means for generating an alarm; * means for detecting a drop or a rise in ambient temperature; * means for delaying the triggering of the generation of said alarm for a period; and * means for triggering the generation of said alarm if at the end of the period the temperature is still dropping or rising.

I..... * ***

2. A system according to claim 1, wherein said system incorporates an interface * . : which communicates with a door chime equipped with at least one speaker and the means for generating an alarm employ said speaker.

3. A system according to claim 2, wherein said door chime incorporates a number of **** different pre-recorded chimes, at least one being predetermined for signalling the dropping or rising of the ambient temperature.

4. A system according to claim 1, wherein the components are provided in a single

wall-mountable unit.

5. A system according to any of the preceding claims, wherein the components are at least in part built-in on the inside of a door and/or window.

6. A system according to any of the preceding claims, wherein the system incorporates a storage medium which togs the occurrences of alarms and means are provided to allow the logged information to be assessed by a user.

7. A system according to any of the preceding claims, wherein the system further comprises means for actuating the closure of a door or window if a predetermined period is exceeded.

8. An indoor Living space ambient temperature sensitive alarm system substantially as hereinbefore described and/or illustrated with reference to any appropriate combination of the accompanying text and/or figures. * *

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