JPS5924764B2 - electronic thermostat - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a thermostat for providing a control signal to a heating and cooling device for maintaining the temperature of a controlled object, such as a room, at a certain desired level. It concerns a precise, electronically operated thermostat.

Thermostats are used to maintain the temperature of a controlled object at a certain desired level. For example, a typical home thermostat is placed in a room and controls the operation of a heater or air conditioner to maintain the temperature of the room at a certain desired level. Typically, a thermostat consists of a bimetallic piece that deforms when the ambient temperature changes and a mercury switch attached to it. When the ambient temperature changes by a few degrees Fahrenheit from the desired level, the pi-metal piece deforms and the mercury in the attached mercury switch moves and bridges the contacts.
This then causes the thermostat to operate the heating and cooling equipment until the bimetallic strip releases the mercury bridging between the contacts. Although this type of thermostat has been widely used in homes and factories, it has several drawbacks, as described below. That is, since the heart of the electro-mechanical thermostat as described above is the mercury switch, dead points and control errors will occur unless the azimuth is specially measured and installed.

Therefore, this type of thermostat is equipped with a lead gauge to prevent control errors from occurring. This results in wasted time and increased costs. The biggest problem with such conventional thermostats is that the amount of deformation D per unit temperature of the bimetal piece varies depending on the temperature.

Therefore, it is difficult to provide such a thermostat with uniform accuracy over its entire operating range.
Furthermore, if you frequently change the reference setting temperature of your thermostat, the actual temperature will eventually change from the set temperature. A discrepancy occurs in the controlled temperature, and this remains forever. Also, since such thermostats are electro-mechanical devices, for example, if an arc is created between the contacts when the circuit is opened,
1. Also, the device must be readjusted for it to work properly. It has the following drawbacks. The object of the invention is to provide an electronically operated thermostat which eliminates the above-mentioned disadvantages.

Another object is to provide an electronic thermostat with uniform and high accuracy over its entire operating range.

This invention can be installed in any direction,
This electronic thermostat has a new structure that guarantees its accuracy regardless of the mounting method.

That is, the thermostat or temperature control device constructed based on the present invention has a thermal relationship with a controlled object, and has a voltage level pattern in binary coded decimal format that represents the temperature of the controlled object. digital temperature signal generating means for generating a temperature signal formed by a signal; and a digital reference for generating a reference temperature signal formed by a voltage level pattern signal in binary coded decimal format representing a desired temperature of the controlled object. temperature signal generating means; a temperature signal formed by a voltage level pattern signal in binary coded decimal format from the digital temperature signal generating means; and a voltage in binary coded decimal format from the digital reference temperature signal generating means. digital comparison means for generating a signal for operating the air-conditioning equipment in response to only one of two types of differences that occur when the voltage level pattern is not equal to the reference temperature signal formed by the level pattern signal; It is configured.

If a failure were to occur in a conventional thermostat using a bimetallic piece, the heating and cooling equipment would operate continuously.

And if this situation were to occur while the householder was away, and the thermostat was controlling the furnace, there would be irreparable damage to the household property. In order to prevent this from happening, the electronic thermostat of the present invention:
The digital temperature signal generating means may be provided with an overheating/supercooling detection comparator or an alarm detector for detecting extreme temperatures and generating an alarm signal.

Other features of the invention will become clear from the following description based on the drawings.

The electronic thermostat according to the present invention is designated by the reference numeral 10 in FIG. 1 and is applied to control a heating and cooling device. The electronic thermostat of the present invention is essentially a device that operates digitally, and includes a temperature signal generator 12 that generates a temperature signal of a controlled object in a binary coded decimal format; By comparing the reference temperature signal generating section 14 which generates a signal of a reference temperature or a desired temperature level in a decimal format signal with the binary coded decimal format signal from the temperature signal generating section and the reference temperature signal generating section. , and a comparator 16 for generating a signal to operate the air conditioner/heater when these two signals in binary coded decimal format are not equal. The electronic thermostat then issues a signal to the air conditioner/heater connected to it to heat or cool the controlled object until the temperature of the controlled object reaches a reference temperature or a desired temperature level. More specifically, the temperature signal generator 12 includes a temperature-to-frequency converter 18 whose frequency changes in proportion to changes in the temperature of the object to be monitored.

The temperature-frequency converter 18 has a thermistor 20 that is thermally related to the controlled object. That is, for example, if the temperature of a room is to be maintained at a desired level, the thermistor 20 would be placed within the room. The output end of the temperature-to-frequency converter 18 is connected by a lead wire 22 to the input end of a decimal counter 24 that counts the 10's digit. It is connected to a counter 28 for counting. Both the decimal counter 24 and the decimal counter 28 are ordinary counters. They count the frequency of the temperature-frequency converter 18, and the sum is sent to the output lines 30A-30D of the decimal counter 24 and the decimal counter 28. A signal formed by a voltage level pattern in a binary coded decimal format, which is a binary code signal, is applied to the output lines 32A-32D.
outputs a signal represented by a voltage sequence of 0 and 1 levels).

These two counters 24, 28 are controlled by a conventional clock oscillator 34 as described below. That is, the output end of the clock oscillator 34 is connected to the lead wires 36, 3.
8 is connected to the decimal counters 24, 28, and while the pulse of the 1-clock oscillator 34 is output to the lead wire 36 (hereinafter, the pulse output to the lead wire 36 is referred to as a set pulse), the counters 24, 28 are connected to the decimal counters 24, 28. performs counting, but when a pulse is output to the lead wire 38, the counter 24,
28 is reset and its contents become zero. For example, when the temperature is O'P (-17.78°C), the temperature frequency converter 18 oscillates at 5000Hz, and when the temperature is 1'F (0
．． If the temperature is configured such that the frequency changes by 10 Hz when the temperature changes (56° C.), when the room temperature is 751=' (23.89° C.), the temperature-frequency converter 18 oscillates at a frequency of 5750 Hz. As will be explained later, the time width of the set pulse is 0.
．． Since the time is 1 second, the counters 24 and 28 have the effect of functioning as 1/10 arithmetic units. As a result, the counters 24 and 28 count the frequency from the temperature-frequency converter 18 using 10 Hz as a unit;
Since 4 and 28 are decimal counters, only the 10 and 100 digits of the frequency of the temperature-frequency converter are counted. That is, the counter 28 is a temperature-frequency converter 1.
The counter 24 counts the 10's digit of the frequency 8, and the counter 24 counts the 100's digit. As mentioned above, when the temperature changes by 1'F (0.56°C), the frequency of the temperature-frequency converter 18 changes by 10Hz, so the content of the counter 28 is the one place of the room temperature, and the content of the counter 24 is the one place of the room temperature. The content of will indicate the tens place of room temperature. Therefore, the signal on leads 30A-30D is 2 times the tens place at room temperature.
In evolved decimal format, the signals on leads 32A-32D represent the ones place number at room temperature in binary evolved decimal format. The aforementioned clock oscillator 34 is connected to a 60 Hz commercial 60 Hz power supply (not shown) via a lead wire 42.
A square wave oscillator 40 receiving a signal and counters 44 and 46
It is composed of.

The counter 44 connected to the square wave oscillator 40 has 6
For each pulse inputted, only one pulse with a time width of 0.1 seconds (hereinafter, a pulse with a time width of 0.1 seconds will be referred to as a 0.1 second pulse) is output. That is, the function is to divide the frequency of the 60 Hz rectangular wave signal output from the rectangular wave oscillator 40 by six. counter 44
The counter 46 connected to the output side of the counter 4
0.1 in response to the leading edge of the 0.1 second pulse that is the output of
The second pulse is output to the underlined lines 36, 38, and 48. This counter 46 receives one 0.1 second pulse (hereinafter referred to as a set pulse) for operating the counters 24 and 28 on the lead line 36 to which the first two pulses are input to the input terminal. When the next pulse is input, a 0.1 second pulse (hereinafter referred to as a latch pulse) is output to the lead wire 48, and when the next pulse is input, a 0.1 second pulse is output to the lead wire 38. It operates to output one 0.1 second pulse (reset pulse). This operation is repeated periodically under the control of a 60 Hz signal from a commercial 60 Hz power supply, so that set pulses, latch pulses, and reset pulses are generated cyclically. The latch pulse is input via lead 48 to display devices 50 and 52.

The display device 50 is connected to the lead wires 32A-32D, and the display device 52 is connected to the lead wires 30A-30D. These display devices are normal ones, and are devices for converting the voltage level pattern signals in binary coded decimal format outputted to the lead wires 30A-30D and 32A-32D into decimal numbers and displaying the converted numbers. It is. That is, the temperature-to-frequency converter 18 is converted into a voltage level pattern signal in binary coded decimal format by the counters 24 and 28.
This is to convert the frequency of the room temperature into a decimal number and visually display it, and the tens digit of the room temperature is shown on the display device 52, and the one digit is shown on the display device 50 in the decimal number. This display is then successively updated to indicate the current temperature by latch pulses applied to lead 48, and the displayed contents are held for one cycle of clock oscillator 34. The two display devices 50 and 52 are actually arranged side by side in order to make it easier to read the temperature display. The reference temperature signal generation section 14 includes two reference temperature setting devices 54 and 62 that convert a decimal number into a voltage level pattern signal in a binary coded decimal format and output the signal. These reference temperature setting devices 54, 62 each have a setting dial 56, 64 and a display section 58, 66 that displays a decimal number, and when the setting dial 56, 64 is turned, the display section 58, The display contents of 66 are changed. Then, the reference temperature setting device 54 converts the decimal number displayed on the display unit 58 into a voltage level pattern signal in a binary coded decimal format and outputs it to the lead wires 60A-60D.
The reference temperature setting device 62 is set to 1 displayed on the display section 66.
The decimal number is converted into a voltage level pattern signal in binary coded decimal format and output to lead wires 68A-68D. The reference temperature setting devices 54 and 62 are arranged in parallel, and one reference temperature setting device 62 sets the tens place of the desired room temperature, and the reference temperature setting device 54 sets the one place of the desired room temperature.

The comparison unit 16 is manufactured by Texas Instruments Inc. It consists of conventional comparators 70, 72, such as the model 7485 manufactured and sold by.

These comparators 70 and 72 compare the magnitudes of the two binary signals input to their respective input terminals, and
It outputs output accordingly. More specifically, one input end of the comparator 70 is connected to the lead wire 32A-
32D, and the other input end is connected to lead wire 60A-
60D connected to D1 and reference numbers 74, 76,
It has three output terminals indicated by 78.

Then, the comparator 70 receives a signal in which the 1's digit of the room temperature input through the lead wires 32A-32D is converted into a binary coded decimal format, and a signal of the 1's digit of the desired room temperature input through the lead wires 60A-60D. The digits are compared with the signal whose digits have been converted into a binary coded decimal format, and the one digit of the room temperature (hereinafter referred to as A temperature) is greater than the one digit of the desired room temperature (hereinafter referred to as R temperature). In this case, a logic value “1” signal is output to the output terminal 74 (A>R terminal), and “O” is output in other cases.
If the one place of temperature is equal to the one place of R temperature, output terminal 7
A logic value "1" signal is output to 6 (A = R terminal), and "0" is output otherwise. If the 1 digit of the A temperature is smaller than the 1 digit of the R temperature, the It operates so as to output a logic value "1" signal to the R terminal), and "0" at other times. Similarly, comparator 72 compares the tens of temperatures.

That is, one input end of the comparator 72 is connected to the lead wire 30.
A-30D, and the other input end is connected to lead wire 68.
Connected to A-68D. If the tens place of the A temperature is larger than the tens place of the R temperature, a logic value "1" signal is output to the output terminal 80 (A>R terminal), otherwise "O" is output. If the tens place of the A temperature is equal to the tens place of the R temperature, a logic value "1" signal is output to the output terminal 82 (A = R terminal), otherwise "0" is output, and the tens place of the A temperature is the same as the R temperature. If it is smaller than the tens place, the output terminal 84 (A
The comparators 70 and 72 operate to output a logic value "1" signal to the R terminal), and output a logic value "0" at other times.A dynamic fixed form inverter is connected to the output terminals of the comparators 70 and 72.

This operation mode reversing device is a device for correctly operating the air conditioner/heater controlled by the thermostat 10 when the A temperature and the R temperature are not equal. That is,
This device operates the heater when the A temperature is lower than the R temperature, and operates the air conditioner when the A temperature is higher than the R temperature. This operation mode reversing device is constructed as follows.

That is, output terminals 80 and 84 of the comparator 72 are connected to terminals 86A and 86B of a two-pole, double-throw switch 86. Then, the terminal 86A and the terminal 86D are connected again to the terminal 86A and the terminal 86D.
6B and the terminal 86C are connected to the terminal D1, and the terminals 86E and 86F are respectively connected to the switch tooth 86G.
and 86H, and the switch teeth 86G and 86H are integrally inserted into either the terminals 86A, 86B side or the terminals 86C, 86D side. The input terminal of the inverter amplifier 90 is connected to the terminal 86 of the switch 86 by a lead wire 88.
E, and its output terminal is connected to one input terminal of a NAND gate N1.

The other input terminal of the NAND gate N1 is connected to a switch tooth 94A of a single pole double throw switch 94 by a lead wire 92. The terminal 94B of this single pole double throw switch 94 is connected to the comparator 7.
0 and the terminal 94C is connected to the output terminal 74 of the comparator 70. The switch 86 and the switch 94 are interlocked as shown by the dotted line 96. Therefore, the switch teeth 86G, 86H of the switch 86
When the terminals 86C and 86D are applied, the switch tooth 94A of the switch 94 becomes tangential to the terminal 94C. Due to the functions of these two switches 86 and 94, the thermostat of the present invention can be used to control both a heating machine and a cooling machine.

The switch positions shown in FIG. 1 are for increasing the temperature of the room to the desired temperature level. To lower the room temperature to the desired temperature level, simply connect each switch to the opposite side. The input terminal of the inverter amplifier 98 is a NAND gate N1
The other output terminal is connected to the input terminal of AND gate A1.

The input terminal of AND gate A2 is terminal 86F of switch 86.
is connected with lead wire 100, and the output of this and AN
The output of D gate A1 is connected to the input terminal of NOR gate NR1. The output terminal of the NOR gate NRl is connected to the input terminal of an inverter amplifier 102, and the output terminal of the inverter amplifier 102 is connected to the connection point 1 between the input terminal of the delay device 108 and one input terminal of the AND gate A3.
04 through a lead wire 106. The output terminal of the delay device 108 is connected to the other input terminal of the AND gate A3. The output signal of the AND gate A3 is sent to a controlled device such as an air conditioner or heater through a lead wire 110, and for example, when the temperature in a room is to be raised, a heater is operated. The delay device 108 connects the lead wire 11
This is to ensure that each counter circuit of the thermostat reaches an equilibrium state by the time a signal is output at It is set slightly larger. That is, the delay device 108 is a device for preventing a signal from being output to the lead wire 110 while each counter circuit of the thermostat is performing a counting operation. Next, the operation of the above-mentioned electronic thermostat will be explained.

First, a case where the switches 86 and 94 are connected as shown in FIG. 1, that is, a case where this electronic thermostat is used in a heating device will be explained. Now, the desired room temperature (R temperature) is set to 7 by the reference temperature setting devices 54 and 62.
2'P (22.22℃), and the current room temperature (A temperature) is 70'F (21.1℃), which is 2'P (1.12℃) lower than that. . Room temperature is 701
:' (21.1℃), so temperature-frequency converter 18
outputs a 5700Hz signal.

Then, when the clock oscillator 34 outputs a set pulse to the lead wire 36, the decimal counter 24 outputs "7" in binary coded decimal format, and the decimal counter 28 outputs "7" in binary coded decimal format.
Instantly memorize "0" in decimal format. Next, when clock oscillator 34 outputs a latch pulse to lead 48,
A decimal number "7" is visually displayed on the display device 52, and a decimal number "0" is visually displayed on the display device 50, indicating to the operator that the current room pollution is 70'F' (21.1°C). let them know that it is. The reference temperature setting device 62 and the counter 24 are
The decimal number "7" is converted into a voltage level pattern signal in binary coded decimal format and inputted to each input terminal of the comparator 72. Upon receiving this, the comparator 72 outputs the signal to the output terminal 82 (A=R terminal). Outputs a logic value “1” signal only to the terminal, and outputs a “0” signal to the other terminals.
(This is because the tens place of the R temperature and the tens place of the A temperature are both "7" and there is no difference between them.

) However, on the other hand, the voltage level pattern signal in binary coded decimal format of the R temperature input to the comparator 70 is
, the comparator 70 outputs the output terminal 78 (
A logic value "1" signal is output to the A<R terminal), and a logic value "O" signal is output to the other terminals (because the R temperature is 1
The digit is "2", but that of temperature A is "0".
). The logical value “1” output to the output terminal 78 of the comparator 70
” signal is input to the NAND gate N1 through the lead wire 92, while the logic value “0” signal outputted to the output terminal 80 of the comparator 70 is inverted by the inverter amplifier 90 to the logic value “1”. It becomes a signal and is similarly input to the NAND-gate N1.

As a result, the NAND gate N1 outputs a logic value "0" signal. This logic value "0" signal is inverted by the inverter amplifier, becomes a logic value "1" signal, and passes through the gate A1 to the NOR gate NRl. is input. On the other hand, the logic value "0" signal at the output terminal 84 of the comparator 72 also passes through the gate A2.
Since the signal is input to the OR gate NRl, the NOR gate NRl outputs a logic value "0" signal. This logical value “0”
” signal is inverted by the inverter amplifier 102 to have a logical value “
1'' signal and is input to the connection point 104. and,
A logic value "1" signal is output from the delay device 108 after a delay of the set delay time T, and as a result, the NAD gate A3 outputs a logic value "1" signal to the lead wire 110 to operate the heater. The lead wire 110 is connected to, for example, an instantaneous closing/slow-opening relay having an opening delay time longer than the clock cycle of the clock oscillator 34, so that the logic value "1" is maintained for a period longer than the clock cycle of the clock oscillator 34. The relay contacts are opened only when no signal is output to the lead wire 110.

That is, this prevents the contacts of the relays from being opened during the counting operation of each counter circuit of the thermostat. When the temperature in the room is increased by the heater and the A temperature becomes equal to the R temperature, the logic "1" signal at the output terminal 78 of the comparator 70 changes to a logic "0" signal.

Then, the NAND gate N1 outputs a logic value "1" signal. This logic value "1" signal is inverted by the inverter amplifier 98 and becomes a logic value "o" signal, which is input to the AND gate A1. Therefore, since the logic value "O" signal is inputted to the NOR gate NRl from the gate A1 and the gate A2, the NOR gate NRl outputs the logic value "1" signal. This logic value “1” signal is applied to the inverter amplifier 102.
Since the signal is inverted to a logic value "O" signal by , no signal is output to the read line 110. Similarly, when the A temperature is higher than the R temperature, no signal is output to the lead wire 110.

For example, if the room temperature rises slightly above the desired temperature (R temperature), the tenth place of the A temperature is equal to the tenth place of the R temperature, but the one place of the A temperature is the one place of the R temperature. Even if it becomes larger, the D lead wire 92 still has a logical value "
0'' signal is output, so no signal is output to the lead wire 110 as in the case described above. On the other hand, if the temperature in the room becomes so high compared to the set desired temperature that the tens place of the A temperature becomes greater than the tens place of the R temperature, a logic value is output to the output terminal 80 of the comparator 72. A "1" signal is output and is input to the inverter amplifier 90 through the lead wire 88, so that a logical "0" signal is input to one input terminal of the NAND gate N1.
Therefore, regardless of the logic value of the signal input to the other input terminal of NAND gate N1, this NAND gate N1 always outputs a logic value "1" signal. Comparator 72
Since a logic value "0" signal is output to the output terminal 84 (A<R terminal) of the gate A2, a logic value "0" signal is input to the gate A2 through the lead wire 100. Therefore, N
Since the logic value "O" signal is input to the OR gate NRl from the gate A1 and the gate A2, the NOR gate NRl
In this case, no signal is output to the lead wire 110, either, if it is selected to output a logic value "1" signal. On the other hand, when the temperature in the room drops so much that the tens place of the R temperature becomes larger than the tens place of the A temperature, a logic value "1" signal is sent to the output terminal 84 of the comparator 72 (A<R terminal). is output.

This logic value "1" signal is inputted to one terminal of the NOR gate NRl through the lead wire 100 and the gate A2. Therefore, regardless of the logic values of the signals input to the other input terminals, the NOR gate NRl always takes the logic value "
0" signal will be output. As described above, this logic "0" signal passes through the inverter amplifier 102 to the node 104, causing the BlAND gate A3 to output a signal to the lead 110 to operate the heater. As is clear from the above, when a logic value "1" signal is input to the gate A2, the NAND signal is output from the lead wire 92.
A signal is output to the lead wire 110 regardless of the logic value of the signal input to the gate N1. In many cases, it is desirable to be alerted when the temperature in a room reaches an extreme value.

In other words, a severe condition occurs due to a malfunction of the heater or the heater, and the temperature of the portion is in the 901:' range (31 to 37
It is conceivable that the temperature could even reach ℃). And if such a situation were to occur in the absence of the householder, the household property would be severely damaged. In order to prevent this from occurring, the present invention provides an output terminal 30A- of the counter 24 that counts the tenths of the room temperature of the thermostat.
One input end of the superheat/supercool detection comparator 112 is set to 30D, and a decimal number is set to the other input end of this superheat/supercool detection comparator. A device (not shown) for converting into a signal and outputting the signal is connected. Assume that the decimal number "9" is set to this. Now the temperature in the room is rising and it's 901? Stands (31~
37°C), the output terminal 3 of the counter 24
From 0A-30D, a signal in binary coded decimal format corresponding to the decimal number "9" is sent to this overheating/supercooling detection comparison device 11.
2, this superheating/supercooling detection comparison device 11
2 generates an alarm signal on the output line 114 and stops the function of the heater connected to it. Ru. next,
The case where the thermostat of this invention is used in a cooling device will be explained.

Insert the switch teeth 86G and 86H of the switch 86 to the side opposite to that shown in FIG.
Connect 6F and terminal 86D. Therefore, switch 9
The fourth switch tooth 94A will be connected to the terminal 94C. In this state, a signal is output to the lead wire 110 only when the room temperature (A temperature) is higher than the desired temperature (R temperature). That is, if the R temperature is now set at 72"F (22.22°C) and the A temperature is 781:' (25.56°C), the comparator 7
A logic value "1" signal is output to the 0 output terminal (A>R terminal). Since the terminal 86B of the switch 86 is connected to the lead wire 88, the output terminal 84 of the comparator 72
The logic value “0” signal of (A<R) is the NAND gate N1
The signal is input to an inverter amplifier 90 whose output side is connected to one input terminal of the inverter amplifier 90. Similarly, a logic value "1" signal is input to the other input terminal of the NA-AND gate N1 through the lead wire 92. That is, two logic value "1" signals are input to the NAND gate N1. Therefore, the NAND gate N1 outputs a logic value "0" signal. This logical value “
The "0" signal is inverted by the inverter amplifier 98 and inputted to the NOR gate NRl as a logic "1" signal. On the other hand, the logical value of the output terminal 80 (A>R terminal) of the comparator 72 "
0” signal also passes through lead wire 100 and gate A2 to NOR
It is input to gate NRl. Therefore, the NOR gate NRl outputs a logic value "0" signal, which is converted into a logic value "1" signal by the inverter amplifier 102, so that the AND
A signal for operating the air conditioner is output from the gate A3 to the lead wire 110. Also, the room temperature rose to 80
'F range (27 to 32 degrees Celsius), this changes the output of the output terminal 80 (A>R terminal) of the comparator 72 from the logic value "0" to the logic value "1". , a logic value "1" signal is input to the gate A2 through the lead wire 100. Therefore, for the same reason as in the heater described above, a signal is output from the AND gate A3 to the lead wire 110. On the other hand, the room temperature is 601
:' range (15~20℃), the comparator 72
The output terminal 80 (A>R terminal) of outputs a logic value "0" signal,
Furthermore, since the output terminal 84 (A<R terminal) outputs a logic value "1" signal, a logic value "0" signal is input to the gate A2, and a logic value "O" signal is input to the NAND gate N1. Therefore, this NAND gate N1 outputs a logic value "1" signal regardless of the logic value of the output of the output terminal 74 of the comparator 70.

Therefore, the NOR gate NRl has two logical values “O
] signal is input, the NOR gate NRl
outputs a logic value "1" signal, so a signal for operating the air conditioner is no longer output to the lead wire 110. When applying the electronic thermostat of this invention to an air conditioner,
A device (not shown) for converting a decimal number into a binary coded decimal format signal connected to the overheating/supercooling detection comparator 112 described above, for example, by setting the decimal number "5". When a person dies, the air conditioner lowers the temperature of the room to around 50'F (1
When the temperature has dropped to 0 to 15° C.), the overheating/supercooling detection comparator 112 outputs an alarm signal to the lead wire 114, making the cooling equipment malfunction. As described above, the electronic thermostat of the present invention has a simple structure, reliable operation, and high precision over the entire operating range.

In many cases, it is desirable to provide a certain degree of temperature difference between the temperature of the room and the reference temperature before outputting a signal to the lead wire 110 to operate the air conditioner.

This is because the difference between room temperature and reference temperature is 1'F (0.56
If the air conditioner is activated when there is a difference in temperature (°C), the number of times the air conditioner will be activated per unit time will be extremely large. Therefore, a difference of 3'F, for example, is provided between the room temperature and the reference temperature, and a difference of 3'F is set between the room temperature and the reference temperature.
It is best to prevent the air conditioner from operating unless a temperature difference of 1.68°C or more occurs. FIG. 2 shows a temperature difference signal generating device for setting a temperature difference between the room temperature and the reference temperature.

This temperature difference signal generator is used in conjunction with the electronic thermostat shown in FIG.
It is possible to generate a temperature difference signal within the range of . In FIG. 2, the temperature difference signal generation circuit includes an adder 118, a differential incrementer 120, a comparator 126, and a flip-flop FFl.
It is composed of etc. The input terminal of the adder 118 is the first
The lead wire 3 is connected to the output end of the decimal counter 28 for the one digit in the figure.
Connected by 2A-32D. The differential incrementer 120 is
It has a numerical value setting mechanism similar to the reference temperature setting device 54 in FIG.
Converts to a voltage level pattern signal in decimal format and outputs it. Now, for example, in the numerical value setting mechanism of the differential incrementer, the decimal number "
3], the differential incrementer converts this 3 to 2.
Lead wires 122A-122D with signals in evolved decimal format
Output to. Then, the output from the counter 28 and the output from this differential incrementer are added by an adder 118, and the sum "5" is output as a signal in binary coded decimal format, and the lead wires 124A-124D are The output from the reference temperature setting device 54 shown in FIG. 1 is input to the other input terminal of the comparator 126 through lead wires 60A-60D. Comparator 126 is 1
It has two output terminals 128.

For example, if the signal formatted in the binary coded decimal format of the adder 118 is smaller than the signal formed in the binary coded decimal format input from the leads 60A-60D, the comparison The device 126 outputs a logic "1" signal to the output terminal 128. In other words, only when the sum of the room temperature and the temperature difference set by the differential incrementer is smaller than the set reference temperature, the output terminal 128 of the comparator 126 outputs the logical value "
1" signal is output (However, this operation is only when the thermostat is controlling the heating machine, and when operating the cooling machine, it operates in the opposite way. In other words, the temperature is set by the room temperature and the differential incrementer. The comparator 126 outputs a logic value of "1" only when the sum of the temperature difference and the set temperature difference is greater than the set reference temperature.
” signal is output. ). Output terminal 128 of comparator 126
is connected by a lead wire 130 to the set terminal of the JK flip-flop or bistable multivibrator FF1.

The reset terminal of flip-flop FFl is the first
Output terminal 76 of comparator 70 (1s digit comparator) shown in the figure
(A=R terminal). NAND gate N2
One input terminal is connected to the "1" output terminal of the flip-flop FFl, and the other input terminal is connected to the output terminal of the inverter amplifier 102 shown in FIG. If a difference signal generator is used, lead wire 106 of the circuit shown in FIG. 1 must be disconnected from connection point 104 and connected to one input of NAND gate N2 of FIG. 2). The output terminal of NAND gate N2 is connected to the input terminal of inverter amplifier 132. The output end of the inverter amplifier 132 is connected to the connection point 104 shown in FIG. 1 by a lead wire 134. Next, the operation of the electronic thermostat to which the temperature difference signal generator configured as described above is connected will be explained. The reference temperature setting device is now 75'F (23.8
9℃), and the differential incrementer of the temperature difference signal generator is 3'
Suppose that the temperature is set to P (1.68°C). If the room temperature is 72'F (22.2°C), then the binary digit of "2" in the ones place of the room temperature 72'F (22.2°C) is 10.
Voltage level pattern signal in decimal format Lead line 32A-
32D is input to one input terminal of the adder 118, and a voltage level pattern signal in binary coded decimal format of the set temperature difference "3" is inputted from the differential incrementer 120 through lead wires 122A-122D. and is input to the other input terminal of adder 118. Therefore, one input terminal of the comparator 126 receives a voltage level pattern signal in binary coded decimal format of "5" which is the output of the adder 118.
4A-124D. Also, the comparator 12
6 is also connected to the reference temperature setting device 54 shown in FIG.
Since the voltage level pattern signal in binary coded decimal coded decimal format of 1's digit of reference temperature 75'P (23.89°C), that is, "5" is input through lead wires 60A-60D, comparison is possible. The output terminal 128 of the device 126 has a logic value “
0” signal is output. Therefore, no signal is output to lead wire 110 because no operation is performed. From the above explanation, even if the room temperature rises above 72'FS (22.2°C), a logic value "1" signal is not output to the output terminal of the comparator 126, and therefore, a signal is not output to the lead wire 110. It is obvious that no output will be generated. However, the room temperature is 71'i
:' (21.67°C), the output of the adder 118 changes to "4", but the 1's digit of the reference temperature is still "5".
Since it remains the same, comparator 126 outputs a logic "1" signal to set flip-flop FF1. As a result, slip-flop FFl outputs a logic value "1" signal, and this signal is input to NAND gate N2. On the other hand, since the room temperature is lower than the reference temperature, the inverter amplifier 102 of the electronic thermostat shown in FIG. 1 naturally outputs a logic value "1" signal, so N
AND gate N2 outputs a logic value "0" signal. This logic value "0" signal is output to the inverter amplifier 132 with a logic value "0".
1'' signal and is input to connection point 104 in FIG. 1 through lead wire 134. Therefore, the lead wire 11
At 0, a signal to operate the heater is output. From what has been described above, it should be clear how this temperature difference signal generator works in order to generate a temperature difference of an appropriate size before the air conditioner is activated. In many cases, the temperature of the object being controlled can also be adjusted remotely.
In other words, it is desirable to be able to change the reference temperature.

In such cases, the thermistor is used to control the temperature of the object (
For example, in the present invention, the reference temperature setting device is placed in a different location, although it has a thermal relationship with the room. However, it is desirable to be able to adjust the temperature of the room in which it is to be controlled, and also from multiple remote points. For example, it is desirable to have a standard temperature setting device in the room where the temperature should be controlled during the day so that the control temperature can be adjusted in that room, but at night it is also possible to adjust the temperature in that room from another remote location. It is desirable to be able to adjust the temperature. For example, if the temperature of the rooms that need to be controlled is the living room or the nursery, the temperature in these rooms would be raised during the day and lowered at night, so it would be desirable to be able to adjust the temperature from the bedroom as well. FIG. 3 shows a circuit for adjusting the temperature of a room from a plurality of different points using a plurality of reference temperature setting devices.

The multistage rotary switch 136 is the reference temperature setting device 1.
4 and comparators 70, 72 with lead wires 60A-60D, 6
8A-68D (shown as a cable in Figure 3). The added reference temperature setting device 214 is essentially the same as the reference temperature setting device 14, and like the device 14, this device 214 is also connected to the switch 1 by lead wires 60A-60D, 68A-68D.
36 and comparators 70 and 72. Then, by operating the multistage rotary switch 136,
Reference temperature setting device 2 with reference temperature setting device 14 added
14 or both lead wires 60A-60
D and 68A-68D can connect to comparators 70 and 72. Next, this operation will be explained.

During the day, the multistage rotary switch 136 is operated to connect the reference temperature setting device 14 to the comparators 70 and 72, while the added reference temperature setting device 214 is disconnected. Then, the electronic thermostat 10
It works in the same way as explained in the diagram. 2. If a temperature difference signal generating device is added to the electronic servostat, it works in the same way as explained in FIG. On the other hand, if you want to change the reference temperature from a remote point regardless of the reference temperature set in the reference temperature setting device 14, operate the switch 136 to change the reference temperature setting device 14 to the comparator 70,
It is sufficient to connect the reference temperature setting device 214, which is separated from 72, to the comparators 70 and 72. The electronic thermostat 10 then operates in the same manner as described above at the reference temperature set by the added reference temperature setting device 214. Although preferred embodiments of the invention have been described in this specification, it is clear that various modifications can be made within the technical scope of the invention.

[Brief explanation of the drawing]

FIG. 1 is a program diagram of an embodiment of the electronic thermostat of the present invention, and FIG. 3 is a block diagram of a temperature difference signal generating device used in conjunction with the electronic thermostat shown in FIG. FIG. 3 is a switching circuit diagram when used in 10... Overall electronic thermostat, 12...
...Temperature signal generation section, 14...Reference temperature signal generation section, 16...Comparison section, 18...
Temperature-frequency converter, 20... Thermistor, 2
4,28...Counter, 34...Clock oscillator, 40...Square wave oscillator, 44,4
6... Counter, 50, 52... Display device, 54, 62... Reference temperature setting device, 56
, 64... Setting dial, 58, 66...
・・Display sound - 70, 72 ・・Comparator, 86 ・・
...2 pole double throw switch, 90,98,102...
... Inverter amplifier, 94 ... Single pole double throw switch, 108 ... Delay device, 112 ...
...Comparator for superheating and supercooling detection, 120...Difference incrementer, 126...Comparator, 132...
Inverter amplifier, 136...Switch, 21
4...Added reference temperature setting device, Al, A
2, A3...AND gate, Nl, N2...
...NAND gate, NRl...NOR gate.

Claims (1)

[Claims] 1. A digital temperature sensor having a thermal relationship with a controlled object and generating a temperature signal formed by a voltage level pattern signal in binary coded decimal format representing the temperature of the controlled object. signal generating means; digital reference temperature signal generating means for generating a reference temperature signal formed of a voltage level pattern signal in binary coded decimal format representing a desired temperature of the controlled object; the digital temperature signal generating means; and a reference temperature signal formed from a voltage level pattern signal in binary coded decimal format from the digital reference temperature signal generating means. digital comparison means that generates a signal for operating the air conditioner in response to only one of the two types of differences that occur when the voltage level patterns are unequal; An oscillator whose oscillation frequency changes as a function of temperature according to the output of a temperature detector disposed in a thermal relationship with the controlled object, and an oscillator connected to the output side of the oscillator to binary code the frequency of the oscillator 10 A counting means for converting into a signal in decimal format and outputting a temperature signal, and a counting means connected to this counting means for setting and resetting the counting means once for a set time in each period. and a clock signal generating means for generating a plurality of reference temperature signals, the reference temperature signal generating means having means for generating a plurality of reference temperature signals, each representing a desired temperature of the controlled object, one switch for selectively connecting at least one to said digital comparison means, said controlling the operation of said heating and cooling equipment so as to maintain the temperature of said controlled space at a desired temperature level. Electronic thermostat for. 2. The electronic thermostat according to claim 1, wherein the counting means comprises a decimal counter for counting increments in the ones place, and a decimal counter for counting increments in the tens place. 3. An electronic thermostat according to claim 1, further comprising delay means for delaying the digital comparison means from generating a signal for operating the air conditioner for a period longer than the set time. 4. The digital comparison means is for comparing a signal in binary coded decimal format which is the output of the digital temperature signal generating means and a signal in binary coded decimal format which is the output of the digital reference temperature generating means. and has at least two output terminals, and outputs an output signal to one of the two output terminals when the temperature signal is greater than the reference temperature signal, and the reference temperature signal is greater than the temperature signal. a comparator incorporating means for providing an output signal at the other of the two output terminals; gate means responsive to the output signal of the comparator to generate a signal for operating the heating and cooling equipment; and; switching means for selectively connecting the gate means to a selected one of the two output terminals of the comparator. electronic thermostat. 5 one sensing stage for said gating means to sense the output signal of said comparator; one output stage for generating a signal to operate said heating and cooling equipment when excited; said sensing stage and said sensing stage; Claims comprising differential incremental means connected between an output stage and for exciting the output stage when the temperature of the controlled object differs from a reference temperature by a preset amount. The electronic thermostat according to item 4. 6. The clock signal generating means periodically generates one set pulse for causing the counting means to perform a counting operation and one reset pulse for zeroing the contents of the counting means at the end of each period. An electronic thermostat according to claim 1, further comprising a pulse generator for generating pulses. 7. The digital comparison means operates to output a signal for operating the heating device when the temperature of the controlled object becomes lower than the desired temperature, and when the temperature of the controlled object becomes higher than the desired temperature. 2. The electronic thermostat according to claim 1, further comprising operation mode reversing means for reversing the operation of said digital comparing means so as to cause said digital comparing means to output a signal for operating a cooling device when said digital comparing means is operated. 8. The digital comparison means determines that the difference between the voltage level pattern signal that is the output of the digital temperature signal generation means and the voltage level pattern signal that is the output of the digital reference temperature signal generation means is larger than a preset temperature difference. 2. The electronic thermostat according to claim 1, further comprising digital differential increment means for not outputting a signal for operating the air conditioner until the heating and cooling device is operated. 9 Digital temperature signal generating means having a thermal relationship with the controlled object and generating a temperature signal formed by a voltage level pattern signal in binary coded decimal format representing the temperature of the controlled object; digital reference temperature signal generating means for generating a reference temperature signal formed of a voltage level pattern signal in binary coded decimal format representing a desired temperature of the controlled object; The voltage level patterns of the temperature signal formed by the voltage level pattern signal in the digital standard format and the reference temperature signal formed by the voltage level pattern signal in the binary coded decimal format from the digital reference temperature signal generating means are not equal. and a digital comparison means that generates a signal for operating the air conditioner in response to only one of the two types of differences that sometimes occur, and the digital temperature signal generation means is configured to generate a signal for operating the air conditioner and the heating and cooling equipment in response to only one of the two types of differences that occur. an oscillator whose oscillation frequency varies as a function of temperature according to the output of a temperature sensor disposed with a oscillator; A counting means for converting and outputting a temperature signal, and a clock signal generating means connected to the counting means for setting and resetting the counting means once for a set time in each period. and the preset binary evolution 1
means for generating a superheating and subcooling temperature signal in response to a signal in decimal format; the reference temperature signal generating means generates a plurality of reference temperatures, each of which represents a desired temperature of the controlled object; Preferably, the method comprises means for generating a signal, and a switch for selectively connecting at least one of the plurality of reference temperature signals to the digital comparison means. Electronic thermostat to control the operation of heating and cooling equipment to maintain the temperature level.