JPS63166188A - Electric hot plate controller - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to electric hot plates for general household use.

Conventional technology Conventionally, in the control device of an electric hot plate, a temperature sensor detects the temperature at the bottom of the plate, and when the temperature is raised to the set temperature, the heater is continuously energized until the set temperature is reached, and when the set temperature is reached. The power to the heater had been stopped.

Problems to be Solved by the Invention However, in the temperature control method described above, the temperature continues to rise for a while even after the power supply to the heater is stopped, so the plate temperature rises to a temperature higher than the set temperature. . The higher the set temperature, the more likely the fluorine layer provided on the plate surface will be thermally degraded due to the above-mentioned temperature overshoot. Therefore, the maximum temperature that can be set must be lower than the maximum temperature that the container can withstand by the temperature difference that overshoots, and even though there are foods that must be cooked at the highest possible temperature, it is possible to set the maximum temperature. This had the disadvantage that the maximum temperature had to be lowered.

In view of the above drawbacks, the present invention aims to eliminate the excessive temperature overshoot that occurs when the plate temperature rises, improve the durability of the fluorine coated surface of the plate, and increase the maximum settable temperature. A control device is provided.

Means for Solving the Problems To achieve this object, the electric hot plate control device of the present invention includes a temperature detection means for detecting the temperature of the plate, a temperature control means for controlling the temperature of the plate, and a temperature control means for controlling the temperature of the plate. A relay connected in series to a heater driven by a heater, a heater power reduction means based on the on/off energization rate of the relay, and a counting means for counting the number of on/off times of the relay.

Effect: With this configuration, temperature control operation by the temperature control means is started, and when the temperature detection means detects that the temperature has reached a certain temperature lower than the control temperature until the plate temperature reaches the control temperature, the heater power is reduced. The reducing means lowers the relay energization rate until the counting means counts the number of times the relay is turned on and off a certain number of times.

As a result, overshoot of the plate temperature with respect to the control temperature can be significantly suppressed compared to when the current is continued until the control temperature is reached.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit block diagram showing the configuration of an embodiment of the present invention. Reference numeral 1 denotes an AC power source, and power is supplied to a heater 3 via a power switch 2. In FIG. A relay contact 4a is inserted into the energizing circuit of the heater 3 to turn on/off the energization, and the relay contact 4a is driven by a relay coil 4b. The temperature of the plate is detected by temperature detection means 6, and temperature control means 7 is controlled by temperature detection means 6. The temperature control means 7 is also controlled by a control temperature selection switch 6 for selecting the plate temperature desired by the user, and the control temperature selection switch e is set to θ1. θ2. Three types of control temperatures of θ3 can be selected.

That is, the temperature control means 7 inputs the output of the temperature detection means 5, adjusts the temperature at the control temperature selected by the control temperature selection switch 6, and controls the energization rate of the relay 4b.
Adjusting heater power.

The operation starts when the control temperature selection switch 6 is pressed.

8, temperature detecting means 6 detects that the temperature control means starts operating and reaches a temperature lower than the control temperature selected at that time.
9 is a heater power reduction means for reducing the power of the heater by changing and reducing the relay energization rate performed by the temperature control means 7 when detected by the heater power reduction means 9, from the time when the heater power reduction means 8 changes and reduces the relay energization rate, Counts the on/off signals sent to the relay 4 by the temperature control means, and
It is a relay on/off frequency counting means that stops the operation of the heater power reduction means 8 when one off period is counted as one time.

The operation of the electric hot plate control device configured as described above will be explained below with reference to the flowchart shown in FIG.

First, in step 101, the control temperature selection switch 6 is operated to select a desired control temperature. Here the control temperature is the second
If θ4 shown in the figure is selected, θ3 becomes the starting point of the heater power reduction means, and at the same time the temperature control operation is started, and in step 102, if the temperature θ at the starting point is θ≧04, the plate temperature is higher than the control temperature. Therefore, proceed to step 103, set the relay on/off period to 1e seconds, set the relay energization rate to o/16, that is, leave the relay off, and repeat until θ<θ4.If θ is θ4, proceed to step 104. The relay energization rate is 1e/1B,
In step 105, if the plate temperature has not reached the control temperature even once and the power has not been reduced by the heater power reduction means, the process proceeds to the next step 106; otherwise, the process returns to step 102. . Step 106
When proceeding to , it is determined whether the plate temperature θ is a temperature at which the heater power reduction means is started. If θ is less than θ3, the process returns to step 102, and if θ≧03, the process proceeds to the next step 107. In step 107, counting of the number of times the relay is turned on and off is started, and at the same time, in step 108, the relay energization rate is reduced to 10,716. Next, in step 109, if the relay on/off number N is 2, the process returns to step 1o2, and the relay energization rate is set to 16/16 in step 104 until θ≧04, and the process returns to step 102 via step 105. repeat.

On the other hand, if N<2 in step 109, step 110
Unless θ≧04, the heater power continues to be reduced at the energization rate in step 10B. θ≧ in step 11o
04, return to step 102 and perform step 1
The process proceeds to step 03, where the relay energization rate is set to 0/16, and the energization to the heater is stopped.The process proceeds to step 102 until θ decreases to θ4.

Similarly, when the control temperature selected by the control temperature setting switch 7 is 03, θ2 becomes the starting temperature for reducing the heater power, and when the control temperature is 02, θ1 becomes the starting temperature for reducing the heater power, as described above. By performing this operation, overshoot when the plate temperature rises is suppressed, and even when the heat load on the plate increases, the power is reduced a certain number of times, thereby preventing the worst case scenario where the plate temperature drops due to power reduction. can be avoided.

Effects of the Invention As is clear from the above description of the embodiments, the present invention includes a temperature detection means for detecting the temperature of the plate, a temperature control means for controlling the temperature of the plate, a relay connected in series with the heater, and an on/off control. By providing a heater power reduction means based on the relay energization rate and a counting means for counting the number of times the relay is turned on and off, it is possible to prevent excessive overshoot when the plate temperature rises.
This improves the durability of the fluororesin coated on the plate surface, and also makes it possible to raise the maximum temperature that can be set. There is also a plate lid,
Even if the plate temperature remains flat or drops due to power reduction when the plate temperature rises due to high or low temperature or power supply voltage, the power reduction by relaying a certain number of times will reduce the power to the maximum level after a certain number of times. It has great practical effects, such as being able to restore power and raise the plate temperature to a controlled temperature.

[Brief explanation of the drawing]

Fig. 1 is a circuit block diagram of a control device for an electric hot plate according to an embodiment of the present invention, Fig. 2 is a plate temperature rise characteristic diagram during temperature control, and Fig. 3 is a diagram of a microcomputer used in the embodiment. It is a program flowchart figure. 3...Heater, 4...Relay, 5.
... Temperature detection means, 7 ... Temperature control means, 8 ... Heater power reduction means, 9 ...
・Means for counting relay on/off times. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2: Monument

Claims (1)

[Claims] A plate placed on the main body, a temperature detection means for detecting the temperature of the plate, a temperature control means for controlling the temperature of the plate, a relay connected in series to a heater driven by the temperature control means, and a relay connected in series to a heater driven by the temperature control means. Heater power reduction means by on/off energization rate and on/off of the relay.
It has a counting means for counting the number of off times, and when the temperature rises from the start of the temperature control operation until the plate temperature reaches the predetermined control temperature, the heater power is increased from a temperature that is a certain temperature lower than the predetermined control temperature. The reduction means lowers the energization rate to the relay to reduce the heater power, and the counting means counts the number of times the relay is turned on and off, and the heater power reduction operation is performed until a predetermined number of times is counted. Hot plate control device.