JPS6239772B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature and humidity controller that controls temperature and humidity.

Conventionally, to adjust temperature and humidity, a dry bulb temperature signal and a wet bulb temperature signal are measured by a temperature/humidity detector, the dry bulb temperature and relative humidity are calculated by a temperature/humidity converter, and the adjustment calculation is performed by a controller. Alternatively, input the dry bulb temperature signal and wet bulb temperature signal into separate controllers, look at a conversion table, etc., find and set the wet bulb temperature to achieve the desired controlled humidity, and then output the control signal. I was trying to get it. However, this method requires at least two controllers, increases the number of devices, requires a lot of wiring, requires a large storage space, and has the disadvantage of being complicated and costly. In addition, when measuring temperature and humidity using thermocouples, etc., if there are variations in accuracy between input signals, this will directly result in calculation errors, making it difficult to perform high-precision measurements.
Adjustment was difficult.

In view of the above points, an object of the present invention is to provide a temperature/humidity controller that can control temperature and humidity with one controller and can be downsized.

FIG. 1 is a block diagram showing an embodiment of the present invention. 11 and 12 are input terminals to which a thermocouple or the like is connected and a dry bulb temperature input signal and a wet bulb temperature input signal are supplied, and 13 and 14 are supplied with an external dry bulb temperature setting input signal and a wet bulb temperature input signal. Input terminal 10 is a reference signal generator formed by short-circuiting input terminals etc. for generating a reference signal; 2 is an input signal supplied to each input terminal 11, 12, 13, 14 of the reference signal generator 10; Switches 21, 22, 23, 2 consisting of signal reed relays, etc.
Input switch that sequentially switches and outputs 4 and 20, 3
4 is an amplifier that amplifies the output of the reference junction compensator 3; and 5 is an A-D that converts the output of the amplifier 4 into a digital signal. converter, 6
is a central processing unit such as a microcomputer that performs arithmetic processing, etc., 7 is a memory that stores the output of the A-D converter 5 and the processing program of the central processing unit, and 8 is a desired dry bulb temperature value. and a setting device for setting the relative humidity value, 9 a display for displaying the set value or input signal value, 10 a control output section for outputting control signals from output terminals 16 and 17, and S the input side of the amplifier 4. This is a short-circuit switch installed in the Note that the input terminals 11 and 12 other than the input switch 2 and the reference junction compensator 3 are connected by a thermocouple or a compensation lead wire.

Assuming that an external setting input signal is being supplied to the input terminals 13 and 14 by operating the setting device 8, the short circuit switch S is opened, and the changeover switches 21, 22, 23, 24, and 20 of the input switch 2 are turned on. The signals supplied to the input terminals 11, 12, 13, and 14 by sequentially opening and closing the signals and the signal from the reference signal generator 10 are taken in, superimposed with a compensation voltage by the reference junction compensator 3, and then sent to the A-D converter. 5 is converted into a digital signal, and stored in a storage device 7 by a central processing unit 6.

At this time, the dry bulb and wet bulb temperature input signals supplied to input terminals 11 and 12 are input to ei ₁ , ei ₂ and input terminal 1
External setting input signals supplied to 3 and 14
Ei ₁ , Ei ₂ , the compensation voltage of the reference junction compensator 3 is Eo, the amplification degree of the amplifier 4 is A, and the drift voltage is △e, then the input signals stored in the memory 5 are ei ₁ , ei ₂ ,
Ei ₁ , Ei ₂ , and the signal A of the reference signal generator 10
-The outputs ei ₁ ′, ei ₂ ′, Ei ₁ ′, Ei ₂ ′, and Ef after D conversion are as follows.

ei ₁ ′=(ei ₁ +Eo+△e)A ……(1) ei ₂ ′=(ei ₂ +Eo+△e)A ……(2) Ei ₁ ′=(Ei ₁ +Eo+△e)A ……(3 ) Ei ₂ ′=(Ei ₂ +Eo+△e)A ……(4) Ef=(Eo+△e)A ……(5) Also, the short-circuit switch S is activated every time the input switch 2 is opened and closed. The cancel signal eo at this time is as shown in the following equation.

eo=△eA...(6) Then, from the above-mentioned signals stored in the memory 7 by the central processing unit 6, the measurement input signals expressed by equations (1) and (2) are always calculated by equation (6). Also, the reference signal expressed by equation (5) is subtracted from the setting input signal expressed by equations (3) and ( ₄ ) _. ，
If Eo ₁ and Eo ₂ are set, it can be expressed by the following equation.

eo ₁ = ei ₁ ′−eo = (ei ₁ +Eo+△e)A−△eA = (ei ₁ +Eo)A ……(7) eo ₂ =ei ₂ ′−eo = (ei ₂ +Eo+△e)A− △eA = (ei ₂ + Eo) A … (8) Eo ₁ = Ei ₁ ′−Ef = (Ei ₁ + Eo + △ e) − (Eo + △ e) A = Ei ₁ A … (9) Eo ₂ = Ei ₂ ′−Ef (Ei ₂ +Eo+△e)−(Eo+△e)A Ei ₂ A ……(10) In other words, as shown in equations (7) and (8), the dry bulb temperature input signal and wet bulb temperature input signal becomes a temperature-compensated signal with drift removed, and the external setting signal also becomes a signal with drift removed, as shown in equations (9) and (10).

The input signals eo ₁ and eo ₂ obtained in this way are subjected to linearization calculation by the central processing unit 6, and are then processed as T _D ,
_TW , and are compared and calculated with the setting signals Eo ₁ and Eo ₂ respectively, and adjustment output signals for the dry bulb and wet bulb temperatures can be taken out from the output terminals 16 and 17 of the adjustment output section 10. Note that when the setting input signal is an input signal equivalent to a thermocouple, a linearization calculation similar to that for the input signal may be performed.

Next, in normal conditions, instead of using the external setting input signal as the setting value by operating the setting device 8 as described above, the setting device 8 refers to the display 9 to determine the dry bulb temperature and relative humidity. can be set. In this case, the central processing unit 6 calculates the wet bulb temperature set value from the dry bulb temperature value and the relative humidity value according to the conversion table stored in the memory 7, compares the wet bulb temperature input signal, and A wet bulb temperature control signal is output together with the temperature control signal. Further, the relative humidity can be determined from the dry bulb and wet bulb temperature input signals and displayed on the display 9 using Pernter's equation shown below.

H=e/es×100(%RH)...(11) e=ew−AP(1+TW/C(TD−TW)
...(12) where H: relative humidity e: saturated water vapor pressure of air es: saturated water vapor pressure at dry bulb temperature ew: saturated water vapor pressure at wet bulb temperature T _D : dry bulb temperature T _W : wet bulb temperature P: air Pressures A and C: constants determined by wind speed, etc. As described above, this invention performs drift compensation by performing AD conversion on the dry bulb and wet bulb temperature signals taken in by the input switch after reference junction compensation. This is a temperature/humidity controller in which a central processing unit performs a comparison calculation with the dry bulb temperature value and relative humidity value set by a setting device, and outputs an adjustment signal.

Therefore, there is no need for a temperature/humidity converter or two controllers as in the past; dry bulb temperature and wet bulb temperature signals can be input with one controller, and settings can be made using relative humidity values, making handling easier. This makes it possible to reduce the size of the device, occupy less space on panels, etc., eliminate the need for wiring connections, and realize an inexpensive and highly reliable temperature/humidity controller. In addition, one reference junction compensator performs temperature compensation, eliminates errors between input signals, and compensates for amplifier drift, making it possible to measure and adjust temperature and humidity with high precision. can. Furthermore, since it is a digital type using a central processing unit such as a microcomputer, highly accurate measurement, setting, and adjustment are possible. Note that since drift compensation is also performed for the setting input signal from the outside, it is possible to adjust with high precision as in the case of manual setting.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention. 11, 12, 13, 14...input terminal, 10...
...Reference signal generator, 2...Input switch, 3...Reference junction compensator, 4...Amplifier, 5...A-D converter, 6...Central processing unit, 7...Storage unit, 8... …
Setting device, 9...Display device, 10...Adjustment output section, S
...Short circuit switch.

Claims (1)

[Claims] 1. An input terminal to which a dry bulb temperature input signal and a wet bulb temperature input signal are supplied, an input switch that sequentially switches and outputs the input signals supplied to this input terminal with a changeover switch, and this input A reference junction compensator that superimposes a compensation voltage on the signal taken out by the switch, an amplifier that amplifies this compensated signal, an A-D converter that converts the output of this amplifier into a digital signal, and this A- A memory device for storing the output of the D converter, a short-circuit switch provided on the input side of the amplifier, a setting device for setting dry bulb temperature values and relative humidity values, and inputs stored in the memory device. calculating the difference between the signal value and the signal value when the short circuit switch is closed, and comparing the linearized signal with a wet bulb temperature value calculated from the dry bulb temperature value and relative humidity value of the setting device, A temperature/humidity controller comprising a central processing unit that outputs a control signal. 2. The temperature/humidity controller according to claim 1, wherein the setting device allows setting by an external setting input signal as well.