JPS58121418A - Temperature control system - Google Patents

Abstract

PURPOSE:To perform high-precision temperature control over the compensation of an error due to various kinds of variance by individual devices, by providing a memory wherein the conversion error compensation rate of the whole device is writable. CONSTITUTION:The momentary voltage and current of a heating body H1 are detected by resistances R1 and R2, a current transformer CT, and a resistance R3 as a voltage and a current sensor. They are converted into digital signals by converting circuit parts 1 and 2, and A/D converting circuits 3 and 4 respectively and they are inputted to an arithmetic processing part 5. On the other hand, the conversion error compensation rate when the H1 is measured is stored in the memory 6 when a temperature control circuit body is assembled and a resistance value for set temperature is calculated from temperature and resistance value relation. Then, it is compared with the resistance value of the heating body H1 varying at every moment.

Description

[Detailed Description of the Invention] Non-invention is electricity! ! This invention relates to a temperature control method used in IIfiA fathom.

There are various methods of temperature control proposed by Denki @ Fakyo Guhiro, one of which is to detect the voltage and current of the heating element, and detect the temperature and resistance value r14.
In addition, there is a method to detect that the temperature has slowed down from 4Ik to a constant temperature and to control the temperature of the heating element. This is a big problem, but as a response to the problem, % more 1lIII11
Providing holes or using parts with poor precision is undesirable as it will lead to low productivity and lower manufacturing costs.0 As a heating element for carpets, etc., use copper, aluminum or other materials. Of course, a! Considering the variation in the heating time, if the heating element has a variation in heating condition, and once the resistance is controlled as the upper limit, the resistance value will vary.
±4
, the temperature coefficient a of AL is extremely small, approximately 0.4X/'C, so 4316÷0.4X/'C2l
It is VC that causes variations in temperature (0℃), and is not suitable for practical use (
It's boring 01 to be able to offer C, other vC turtle pressure, electric tl
Errors in the sensor and converter that detect the Lt also have an impact.

So, in order to deal with these problems, as mentioned above, the heating element and the
It is not advisable to use parts with low precision, but this leads to a decrease in productivity and an increase in costs.This idea was proposed in view of the above points.

The conversion error correction factor kl of the entire device is used as memory (ROM, RAM %), and the correction factor for errors caused by variations in each unit is used for each individual device.

Without the use of special high ttlK heating elements or components.

The purpose is to provide a highly refined temperature control system.

Below are 5I! DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the drawings illustrating the embodiments. The drawings show an embodiment in which the temperature control method of the present invention is implemented in (b) a circuit board. To explain the configuration in the figure, a heating element H1 and a current transformer CT for detecting the current are connected in series to one end of an alternating current power source E such as a commercial power source E via a contact St of a relay R to be described later. A series circuit of voltage dividing resistors R1° for voltage detection is connected to one end of the circuit. The secondary glue winding of the current fircT is
A resistor R1 is connected in parallel to the friend that converts L into a voltage, and the input voltage signal converter circuit s2 at one end of the resistor R1 is connected in parallel.Similarly, the voltage signals generated at both ends of the resistor & are input to the converter path sl, respectively. 0 conversion circuit connected to add 1.
2) A human power signal which is an alternating voltage (k) is used to cut the hair to the desired level and get a iiamq meeting.9. The scaling circuit and the peak detection circuit are 0-order, which is to be scaled, and the analog-to-digital conversion circuit (hereinafter referred to as I A/D conversion circuit) is written on the output terminals of the conversion circuit sections 1 and 2. )3.4
07 is a temperature setting section, which is connected to the input terminals of the n% A/D conversion circuits 3 and 4, respectively, and to the input port of the arithmetic processing section 5 constituted by a microprocessor V or the like; The nine theta corresponding to the desired fjA degree is sent to the arithmetic processing section 5. Furthermore, the memory is composed of ROM, RAM, etc. in which conversion error correction factors of six companies are stored in advance.

- The transistor Tr is a privately manufactured one for the relay R', and the base is connected to the control output terminal of the arithmetic processing section 5, and the transistor Tr is connected in series between the collector and the power supply from the control V of the arithmetic processing section 5. The relay rt is turned on and the contact s' is turned on and off as appropriate.

Hereinafter, the operating state will be explained based on the temperature tlIIJ@ circuit shown in the figure. Therefore, the voltage of the heating element H+ between %-
The voltage tIL is the voltage, and the resistance R1p serves as a current sensor.

Transformer CT, resistor R8 is detected, conversion circuit section 1
, 2, A/D [Converted into corresponding digital signals by conversion circuits 3 and 4 and processed! In the 0 performance processing W7a5 input to 1115, R = Schiff = '---' - (1) (where R is the resistance value at that time, # is the detected voltage, This is a digital signal corresponding to the detection current.). - 10,000, the memory 6 contains temperature control - change y1 when measuring the heating element H8 during assembly of the road body. The w4 difference correction factor is stored, and taking this into account, RT ” Rt (1+alt(T
− is set from the relationship between temperature and resistance value, which is <2) i
Calculate the resistance value RT at 1 degree T and compare it with the obtained R using formula (1), that is, the resistance value of the heating element H3, which changes at each moment. As a result, if it is detected that the two match, the heat generation starts. Transistor Tr3 to control energization to body H2
Drive the gate relay R and turn off the contact St.

For example, TTF, when assembling the temperature control circuit body, the heating element island was measured, and now the temperature was 6℃ at 6111W, and the resistance value was 10.3g4Ω.
The value or ratio corresponding to the resistance value of 0.3840 is memorized, and in actual use, the set temperature indicated in the temperature setting section 7 is set to 1 heating element H, assuming that the temperature is expressed in degrees Celsius.

The resistance value of is 11.4028 (Re.=IO,384(
1-1-0,004 (from May 60) and 7t
#ff1 TIJ control relay R is controlled to open, and after the elapse of the uniform footing time, relay Rt is closed, and the operation is performed so that H, Q>resistance value becomes 11.402 Q. Also, another device is used. Then, the resistance value of H at 5℃ is #112.1891
11 tf, 6 tftlljllll rare i1 time no 9 The resistance value of the heating element H, output on the L/- open signal is 13
．． 384Ω is enough.

As described above, in the present invention, the voltage of the heating element.

In a device that detects the resistance fit from the current, compares it with the resistance at a predetermined temperature, detects that a predetermined temperature has been reached, and controls the temperature of the heating element by controlling the temperature of the entire device. A memory is provided to write the conversion vi4 difference correction factor, and appropriate correction is made according to the contents of the memory.yc4! Since it is possible to correct 1 difference due to variations in cypress, even if there is a large conversion error due to variations in the resistance wax of the heating element and circuit components, it will not affect the accuracy of the temperature side axis. 0 that can perform highly accurate a degree control

[Brief explanation of drawings]

Figure a The temperature control force type of the present invention is realized as a circuit configuration.
This is an example. 1.2... Hentai Circuit Sister, 3,4...A
/D conversion circuit, 5... Arithmetic processing m1tt%6...
...Memory, 7...Temperature setting section, Hl...
... Heating element, E ... AC electric wire, CT ...
... Variable current, R + , &s Rs ... Resistance, R ... St' * S ... Relay contact % Tr, ... Transistor patent issued seller
Matsushita Electric Works Co., Ltd.

Claims (1)

[Claims] The resistance m'i is detected from the voltage and current of the heating element, and the predetermined temperature F!
The temperature is controlled by detecting the temperature C that has reached the required temperature by comparing it with the resistance value in the LWC, and controlling the energization to the heating element.
At m, the memory that can include changes in the entire device and correction of mis-noodles is created, and the sleeves are corrected as appropriate in the 5 valleys of the memory, and each dan variation for each individual koji is corrected. It is possible to correct the error caused by '(f-% characteristic).