JPS6167116A - Temperature controller - Google Patents

Abstract

PURPOSE:To attain temperature control with high accuracy by applying a voltage from a connecting point between a thermister and a resistor connected in series thereto while dividing a power supply voltage, a voltage from a slider of a variable resistor and a voltage from a connecting point of two series resistors to a microcomputer respectively. CONSTITUTION:When a power 4 is applied to the controller, the microcomputer 2 turns off a relay 7 and a heater 8 as the initial setting. Then the power voltage V is divided by a temperature sensor 1 and a resistor 6 and a voltage V1 is fed to the computer 2. Further, a voltage V2 is fed to the computer by adjusting the power voltage V by an adjusting value setting resistor 5. Moreover, the voltage V is divided by adjusting value setting resistors 3a, 3b to apply a voltage V3 to the computer 2. The computer 2 applies temperature control with high accuracy b inputting the three voltages V1, V2 and V3.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a temperature control device that is equipped with a one-chip microcomputer and controls the temperature inside a heating chamber of, for example, an electric stove or a gas oven, by simply inputting adjustment value settings. This allows the temperature control characteristics to be easily changed.

Conventional configuration and its problems Conventionally, in temperature control devices equipped with a one-chip microcomputer (hereinafter referred to as a microcomputer), the temperature control program is stored in a mask ROM, so it is difficult to change the temperature control characteristics after the microcomputer is completed. is not easy. For example, changing the temperature sensor, changing the installation location of the temperature sensor, or if the temperature sensor is located far from the controlled object, the temperature of the controlled object may change even if a part of the structure of the control device itself is changed. A change occurs in the temperature difference between the temperature and the temperature of the temperature sensor atmosphere. In such cases, it is necessary to develop a dedicated microcomputer with a temperature control program suitable for the purpose, which requires a lot of money and time. Once the program was completed and an order was placed for microcomputer development, it was therefore not possible to make any changes to the parts related to temperature control. Additionally, since the microcontroller was a dedicated part, microcontroller development was required each time a new model was developed. As mentioned above, there were many problems in developing a temperature control device equipped with a microcomputer.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and aims to make it possible to vary the control characteristics of a temperature control device including a microcomputer using a simple adjustment method.

Structure of the Invention In order to achieve the above object, the temperature control device of the present invention includes a temperature sensor, a conversion device that converts the resistance value of the temperature sensor into a voltage value, a one-chip microcomputer with an analog input terminal, and a temperature control device. The one-chip microcomputer is configured to include a setting device and an adjustment value setting device, and the one-chip microcomputer performs temperature control using three inputs: the conversion device, the control temperature setting device, and the adjustment value setting device;
The control characteristics can be varied by simple adjustment value settings, and the microcomputer has the advantage of being versatile.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a circuit of a temperature control device according to an embodiment of the present invention. 1 is the temperature sensor, 2 is my resistor 3a,
3b divides the power supply 4 to obtain a voltage V, which is input to 13 of the microcomputer 2.

5 is a volume to adjust the voltage 2 applied to the microcomputer I2. This voltage corresponds to the control set temperature. A resistor 6 divides the power supply 4 together with a temperature sensor to obtain a voltage v1, which is input to the microcomputer 2 at 11. This voltage v1
However, there is a corresponding increase in the control temperature.

7 is a relay, which outputs 0. controlled by A heater 8 is controlled by a relay 7.

The temperature sensor is a negative characteristic thermistor, and the relationship between its temperature and resistance value is shown in Figure 2. Change the subsequent processing method based on the I1 input of microcomputer 2. Flow 13 is where this judgment is made. When the voltage of the power source 4 is set to V, and V 3 <s, the process goes to flow 14, and the temperature T1 is corrected according to the following equation.

T1- TI + KI X V3 (K1 is a constant)
When v 2 S≦v3≦sV, the process goes to flow 15 and the temperature T1 is corrected according to the following equation.

TI = TI X (K2XV3) (K2 is a constant) When V 3 > +V, no correction is performed.

When the above correction processing is completed, the process goes to flow 16, where the control temperature T1 is compared with the set temperature I2,
When TI<I2, the relay 7 is turned on and the heater 8 is energized to raise the temperature. When T1>I2, relay 7 is turned O.
Turn off the heater 8 to lower the temperature. After the control processing of the relay 7, the routine returns to routine 10 in which Vl, v2, and v3 are input again, a closed loop is formed, and temperature control is continued.

As described above, according to this embodiment, the temperature control characteristics can be easily changed by changing the voltage applied to the human power for adjustment to the microcomputer. 1 and resistor 6, the relationship between voltage v1 and temperature is as shown in FIG. FIG. 4 shows a flowchart of the temperature control program of the microcomputer.

Hereinafter, the operation of the above configuration will be explained based on the flowchart shown in FIG.

First, when the power is turned on to this device, the microcomputer 2 sets the relay 7 to 0FFL and the heater 8 to OFF in flow 9.
F. Next, the microcomputer 2 receives the voltages V1 and V2 input to the analog human power 11, I2, and I3 in flow 10, respectively.
, load v3.

Since voltage v1 does not change linearly with respect to temperature as shown in FIG. 2, this correction is performed in flow 11,
Perform linearization. Voltage V1, V input to microcomputer 2
2 is the temperature information input as voltage, so
Flow 12 converts these voltages v1, v2 into temperatures TI, I2, respectively. Next, microcomputer 2 improves the accuracy of the two preset threshold controls depending on the value of voltage v3 for setting the adjustment value, and also allows the same microcomputer to be used in many similar devices. This is extremely beneficial as it saves time and reduces development costs. Moreover, this adjustment method also requires only one resistance change, and is advantageous in terms of cost.

As described in detail, the temperature control device of the present invention has a configuration in which a set value setting device is provided, the output of which is input to a microcomputer, and the control characteristics can be varied according to the input amount. Therefore, the microcontroller can be made versatile, and development costs can be reduced.
This method has a great effect on time savings, and allows an inexpensive and highly accurate temperature control device to be developed and provided in a short period of time.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a temperature control device that is an embodiment of the present invention, FIG. 2 is a temperature-resistance characteristic diagram of a temperature sensor used in the same device, and FIG. The voltage characteristic diagram and FIG. 4 are flowcharts of the temperature control program of the microcomputer used in the present invention. 1... Temperature sensor, 2... One-chip microcomputer, a... Adjustment value setting device, 5... Control 8 temperature setting volume. Name of agent: Patent attorney Toshio Nakao and one other name
1 Figure 2 Figure 3 4 17A Figure 4

Claims (2)

[Claims] (1) A temperature sensor, a conversion device for converting the resistance value of the temperature sensor into a voltage value, a one-chip microcomputer with an analog input terminal, a control temperature setting device, and an adjustment value setting device; A temperature control device configured such that a chip microcomputer performs temperature control using three inputs: the conversion device, the control temperature setting device, and the adjustment value setting device. (2) At least one threshold value is set as a criterion for determining the amount of input from the adjustment value setting device, and the adjustment method is changed depending on whether it is below or above that threshold, and the input amount is within a certain threshold value. 2. The temperature control device according to claim 1, wherein the temperature control device has a method of setting an adjustment amount proportional to the amount.