GB2180963A - Wireless control of temperature - Google Patents

Abstract

A temperature control apparatus for a heating or cooling apparatus with a temperature sensor 15, a computer 2 producing a control signal in response to temperature during an operation period and thereafter entering a halt period, a transmitter 21 for sending the control signal to the heating or cooling apparatus and a timer 23 for controlling the computer. The timer 23 is activated by commencement of the operation period to reactivate the computer after a predetermined time. A desired temperature is set at 11. The CPU 3 produces a ramp voltage by circuit 17 for comparison with the measured temperature; a high or low signal is sent from 19 to CPU 3 according to whether the instant temperature is above or below the ramp level. <IMAGE>

Description

SPECIFICATION Wireless remote control apparatus and method of operating The present invention relates to a temperature control apparatusfora heating andlorcooling Sappara- tus, in particular, to a wireless remote control apparatus using a battery as a power supply, and its operating method.

Wireless type remote control apparatus are now usedforcontrolling apparatus such asair10con- ditioners. Conventionallythis control apparatus uses a battery as a power source. Since it is troublesome to frequently change batteries, small power consumption is required of this type of control apparatus.

One known apparatus of this type includes a tem perature sensing circu it for detecting the tem perature in a room, a comparing circuit comparing the detectedtemperaturewith a desired temperature and producing a signal, a transmitting circuit sen ding the signal to the apparatusto be controlled, such as an air conditioner, and a timer. the timer enablesthe remote control apparatus to detect the temperature and to send a regular signal intermittently.

This apparatus has relatively low powerconsumption, butfurther reduction in consumption is desirable. Because the timer is operated irrespective of operation of the circuits described above, it takes longerthan necessary to completely carry out the circuit operations. In other words, in spite of completion of the 30 operations, the circuits are still supplied with useless power bythetimer.

It is an object ofthe present invention to provide an improved wireless type remote control apparatus achieving small powerconsumption.

ltisanotherobjectofthe invention to provide a unique operating method of a wireless type remote control apparatus.

According to one aspect of the present invention there is provided a wireless type control apparatus for controlling a heating or cooling apparatuscomprising: temperature sensing meansforproducing asignal indicating the temperature; computer means having a CPU,for receiving said temperature signal and producing a control signal in response thereto during an operation period and thereafter entering a halt period; transmitting meansfortransmitting said control signal to said heating or cooling apparatus; and timer means for controlling the operation and halt state ofthe CPU, said timer being activated bythe commencement of said operation period and reactivating said computer means after passage of a predetermined time.

According to a second aspect ofthe present invention there is provided a method of operation of a wireless type control apparatus including a temperature sensing means, a microcomputer having a CPU, a transmitting means, and timer means, having a C-Rtimercomprising the steps of:: sensing a temperature and producing from the temperature sensing means a temperature signal corresponding to the sensed temperature; producing a control signal from the CPU in re sponseto said temperature signal; transmitting the control signal from the trans mitting means to an apparatus to be controlled in responsetoatransmitcommandfrom said CPU; producing a given signal from the CPU when the second orthethird step is completed; charging the C-R timer in response to the given signal; producing a signal from the CPU and causing the CPU to enterthe halt state when a voltage ofthe C-R timer has reached a prescribed potential; discharging the voltage of the C-R timer; and shifting from the halt state of the CPU to the operation state when the discharged voltage ofthe C-R timer has fallen to a predetermined potential.

For a better understanding ofthe present invention referencewill nowbemade,bywayofexample,to the accompanying drawings, in which: Figure 7 shows a block diagram of an embodiment of a wireless remote control apparatus according to the present invention usedforan airconditioner; Figure 2 shows a circu it diagra m of a timer circuit of Figure 1; and Figure 3A, 3B and3Cshowtime charts showing re spectivelythe voltage at point A in the circuit diagram of Figure 2, the output of the CPU output port 38 and the operation and halt period ofthe CPU.

An embodimentofthe presentinventionwill now be described in more detail with reference to the accompanying drawings.

Referring to Figure 1,thewireless remote control apparatus includes a battery 1 as a power source, a microcomputer 2 composed of CPU 3, ROM 5 and RAM 7, a re-set circuit 9 for providing a re-set signal to a re-setterminal ofthe CPU priorto the commencement of operation ofthe microcomputer2, and an operation circuit 11 for presetting a desired temperature in a room. The operation circuit 11 is provides with an on and off switch forcontrolling the con- ditioner.Atemperature sensing circuit 13 includes a temperature sensor 15 for sensing the temperature in the room and producing a firsttemperature signal (an analog value corresponding to the sensed temperature), a comparison signal producing circuit 17 for producing a second signal in response to an output of the CPU, and an A-D converter circuit 19 which also compares the first signal with the second signal to produce a third signal (a digital signal). A transmitter 21 sends from the CPU to the apparatus to be controlled a control signal, modulated with light or sound waves, in accordance with the third signal.

Operation ofthe above-described circuits will be described hereinafter. The CPU sends its output sequentially to the comparison signal producing circuit 17, and causes itto produce the second signal ta progressive step function voltage). The second signal and the first signal, corresponding to the detected temperature fed from the temperature sensor 15, are compared intheA-Dconverterandcompara- tor circuit 19. As a result, circuit 19 produces the third signal.When the output (thethird signal) oftheA-D converter 19 changes from L (a low level potential) to H (a high level potential) or from H to L, the CPU det ectsthetemperature atthattime on the basis ofthe output from the CPU to the comparison signal producing circuit 17. then, the CPU converts to the control signal either the detected temperature itself or, for example the difference between the detected temperature and a desired temperature, and sends the control signal to the transmitter 21. The transmitter 21 received the control signal from the CPU, and sends it modulated with either light or sound waves two a receiver inthe airconditioner (notshown). Oper- ations ofthe air conditioner are then carried outaccording to the control signal.A construction of a timer circuit 23 and the CPU which are usable in the embodiment ofthe present invention will now be described.

The wireless type remote control apparatus further includes timer circuit 23, such as e.g., a C-R timer, for determining the halt period of time of the CPU, which is controlled by a fourth signal (a high level potential) fed from the CPU. The CPU produces a fifth signal (a low level potential) and enters the halt state by itself when the timer circuit 23 is charged up.

Figure 2 shows a circuit diagram ofaC-Rtimeras an example of a suitable timercircuit and CPU. A switch 26 in the operation circuit 11 is the on and off switch. One end 26a of the switch 26 is connected to an output port 28 ofthe CPU, whilethe other end 26b is connected to an output port 30 of the CPU through a backward connected diode D1, and is connected to an operation-halt port32through a backward connected diode D2. A power supply voltage VDD is connected to the emitter of a NPN transistor Tr th roug h a resistor R2to a contact a of a switch 36forselecting a temperature sensing mode.

The base oftransistorTr is connected to an output port38 ofthe CPU, andthe emitteris grounded through the C-R timer 23. The C-R timer 23 informed with a parallel connected circuit of a resistor Rt and a capacitor C. A connecting point A between the emitter ofthe transistorTr and the C-R timer 23 is connected to the operation-halt port32 through a contact b of switch 36 and a resistor R3. The switch 36 enables the userto selectthetemperature sensing position (the remote control apparatus side or the apparatus side to be controlled).

When switch 36 is atthe contact a,temperature sensing is carried out at the apparatus side to be controlled. The CPU operates only when the on and off switch 26 is operated and then shifts to the halt state after sending a signal (on or off signal) once.

When the switch 36 isatthecontactb,temperature sensing is executed at the remote control 35 apparatus side. A detailed operation will be described as follows.

When on and off switch 26 is closed, an L output (a low level potential) of the output port 28 is applied to the operation-halt port 32 through the diode D2. The CPU 3 responds to the change from H (a high level potential) to L of the operation halt port 32 and begins operation. When the CPU starts operation, the comparison signal producing circuit 17 and the A-D converter 19 operate and the first signal (the sensed tem- perature) produced by the sensor 15 is converted to thethird signal (a digital signal) and applied to CPU 3.

At this time, ifatransmitcommand is in the CPU, this command iscarried out bythetransmitter21.The conditions producing the transmit command are as follows: 1) When the difference between the latesttemperature and the prior temperature is greater than a prescribed constant value; 2) When a predetermined period of time passes after the priortemperature data has been transmitted; or 3) When the on and off switch is operated.

Then, once one temperature detecting cycle is completed, the CPU outputs the fourth signal (a high level potential) from the output port 38 (time T1 as shown in Figure3B). The fourth signal issenttothe base oftransistorTr, transistorTr is turned on, and power is supplied to C-R timer 23.A chargetherefore builds up on the capacitor C ofthe C-R timer 23, and the voltage at the emitter oftransistortr (point A in Figure 2) gradually rises. Afterthe voltage of the capacitor C has reached a sufficient charged level, (point At, in Figure 3A), CPU 3 produces the fifth signal (a low level potential at time T2 in Figure 3B) and enters the halt state attime R3 in Figure 3C. Atthesame time, since the fifth signal is sent to the base of trans istorTr,transistorTr is turned off, and the C-Rtimer 23 discharges.In other words, the accumulated charge in the capacitor Cflowsto earth throughthe resistance Rt, and the voltage potential of the point A shown in Figure 2 gradually falls (from point A1 in Figure 3A). Atthis time, the CPU stays in the halt state. then, when the voltage potential of point Afalls from point A1 to point A2 (as shown in Figure 3A), at which the voltage potential has fallen to a standard voltage vex used by the CPU to distinguish H (high level potential) and L (a low level potential), the CPU again begins operation at time T4 in Figure 3C. Therefore, the CPU goes through repeated abovedescribed duty cycles.

As described above, according to the embodiment of the present invention,the CPU is operated only for the period oftime of approximately 500 microseconds necessary for detecting the temperature, and afterthat the CPU stays in its halt state for a predetermined period oftime such as e.g. 3 minutes by means ofthe C-R timer. As a result, the power consumption ofthe control apparatus including the CPU by the above-described construction and its operating method is low, so that battery iife which was formerly only some tens of days is extended to some months or a year or longer. Thus, excellent energy saving is obtained. The extended battery life avoids troublesome battery replacements, providing convenience in use. Additionally, it is possible to reduce the battery size and numbersinthewirelesstypere- mote control apparatus, and to make the apparatus more compact.

Various modifications will become apparentfor those skilled in the art having the benefit oftheteachings of the present disclosure without departing from the scope thereof. Thereafter, the claims should be constructed to include such modification.

Claims (9)

1. A wireless type control apparatus for con- trolling a heating or cooling apparatus comprising: temperature sensing means for producing a signal indicating the temperature; computer means having a CPU,for receiving said temperature signal and producing a control signal in response thereto during an operation period and thereafter entering a halt period; transmitting meansfortransmitting said control signal to said heating orcooling apparatus; and timer means for controlling the operation and halt state ofthe CPU, said timer being activated bythe commencement of said operation period and reactivating said computer means after passage of a predetermined time.

2. A wireless type control apparatus according to claim 1, wherein said temperature sensing means includes a comparison signal producing circuitwhich produces a comparison signal in response to an output ofthe CPU and meansforcomparingsaid comparison signal with said temperature signal.

3. Awireless type control apparatus according to claim 2 in which said comparing means include an A-D converter.

4. A wireless type control apparatus according to claim 1, wherein said timer means includes a C-R timer, which begins to charge when said timer means receives a signal from the CPU, and said CPU produces a signal and enters said halt state itself when the C-R timer has reached a prescribed charged level, and which beging to discharge when said timer means receives a signal from the CPU, and said CPU again begins operation when the voltage potential of the C-R timer has fallen to a prescribed level.

5. A method of operation of a wireless type control apparatus including a temperature sensing means, a microcomputer having a CPU, a trans mitting means, and a timer means, having a C-R timer comprising the steps of: sensing a temperature and producing from the temperature sensing means a temperature signal corresponding to the sensed temperature; producing a control signal from the CPU in responseto said temperature signal; transmitting the control signal from the trans mitting means to an apparatus to be controlled in response to a transmit command from said CPU; producing a given signal from the CPU when the second orthethird step is completed; charging the C-Rtimer in responsetothegiven signal;; producing a signal from the CPU and causing the CPU to enterthe halt state when a voltage of the C-R timer has reached a prescribed potential; discharging the voltage of the C-R timer; and shifting from the halt state ofthe CPU to the oper ation state when the discharged voltage ofthe C-R timer has fallen to a predetermined potential.

6. A method as in claim 5, further including the step of producing acomparisonsignalwhenthetem- perature sensing means receives an output from the CPU.

7. A method as in claim 6, further including the step of comparing the temperature signal with the comparison signal.

8. A wireless type control apparatus substantially as hereinbefore described with reference to the accompanying drawings.

9. A method of operation of a wireless type control apparatus substantially as hereinbefore described with reference to the accompanying drawings.