JPS63166182A - 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 the Invention The present invention relates to an electric hot plate for household use.

2. Description of the Related Art As shown in FIGS. 4(a) and 4(b), a conventional hot plate detects the temperature of a υ plate 4 by a temperature detecting means 2 such as a bimetal thermometer connected in series to an AC power source 1.
The temperature of the metal plate 4 in which the heater 3 is embedded is controlled by mechanically opening and closing the contacts.

Problems that the invention attempts to address However, the above configuration has the disadvantage that the contacts of the bimetal thermostat will easily weld, and if these mechanical failures occur, if the power is connected, the switch is turned on, and left unattended, it will continue to operate indefinitely. was. As a result, the high temperature state persisted, and there was a risk of burns caused by unintentional touching or, in the worst case scenario, a fire. It also has the disadvantage of consuming unnecessary power forever.

In view of the above-mentioned drawbacks, the present invention provides a control device for an electric hot plate, which prevents the high temperature from persisting even if the user forgets to turn off the switch and leaves it unattended, thereby preventing dangers such as burns and fire. It is something to do.

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, and a temperature control means for controlling the temperature at a plurality of temperature points. , a control temperature setting means for setting a control temperature, a timekeeping means for starting time measurement from the time when the temperature control operation is started by the temperature control means, and a control temperature changing means for changing the control temperature; However, the set temperature of the control means is changed to the lowest temperature after a certain period of time has elapsed.

Operation With this configuration, the control temperature setting switch is pressed, the temperature control means adjusts the plate temperature to a constant temperature based on the information from the temperature detection means, and at the same time, the time measurement means starts measuring time. If the timer measures time for a certain period of time or more, or if no switch is pressed for a certain period of time, the control temperature of the temperature control means is changed to the lowest control temperature by the control temperature changing means, and the plate temperature is dangerously high. The system automatically transitions from one state to a lower, safe state.

EXAMPLE Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.
1 is an AC power supply, 3 is a heater, and 6 is a relay that cuts off the power supply to the heater 3. It is composed of a contact 5a and a coil 5b, and the contact 5a is inserted into the energization circuit of the heater 3. The coil 5b is controlled by temperature control means 7.

The temperature control means 7 performs control operations based on a signal from a temperature detection means 6 which detects the temperature of the plate, which is composed of a negative characteristic thermistor or the like. The temperature control means 7 still includes a start switch 8 that starts when pressed once and stops when pressed once again, a control temperature setting means 9 that sets the control temperature of the temperature control means 7, and a control temperature changing means 1.
I am trying to give 2 signals. The control temperature setting means 9 is provided with a setting switch 10 for setting the temperature.
As shown in the figure, θ1. θ2. Three types of control temperatures of θ3 can be set.

Reference numeral 11 denotes a time measuring means that starts measuring time from the time when the start switch 8 is pressed. The control temperature changing means forcibly changes the control temperature of the temperature control means to the lowest control temperature (80°C in this example) when the timer 11 measures time for a certain period of time (ω minutes in this example). It is supposed to be done.

Regarding the electric hot plate control device configured as described above, its operation will be explained below when the control temperature θ8 is θ3 in FIG.
This will be explained with reference to a plate temperature characteristic diagram showing changes in plate temperature at the time of , and a flowchart shown in FIG.

First, when the start switch 8 is pressed, the control temperature θ8 of the temperature control means is set to 01 (80° C.) in step 101, and the time measurement T by the time measurement means 11 is reset in step 102 to start time measurement. In step 103, the clock means 1
If the time T measured in step 1 is less than ω minutes, step 104
The temperature detection means 6 detects the plate temperature θ, and in step 105, the plate temperature θ is compared with the set control temperature θ.If θ is less than θ8, step 106
The relay is turned on, and if θ≧08, the process proceeds to step 107, the relay is turned off, and the power supply to the heater is stopped. After that, the process proceeds to step 108, and the time T of the timer 10 is counted up every second. In step 109, it is determined whether the control temperature setting switch 10 has been pressed. If it has not been pressed, the process returns to step 103. , the following operations are similar. If it is pressed, proceed to step 11o, and if the currently set control temperature θ8 is not θ3 (230'C), that is, θ8 is θ1 (so'c) or θ2.
(180'C), the process proceeds to step 112, and the control temperature is reset to a higher control temperature. If 08=03 in step 110, 08=01 is reset in step 111, and the process returns to step 103.

If the measured time T is 60 minutes or more, the process proceeds to step 111, where the control temperature is forcibly set to θ1, that is, the minimum control temperature of 80°C, and the process proceeds to step 104. This state is shown in FIG. After that, as shown in step 109, the start switch 8 is pressed and the process is stopped once and then restarted.Since the time T is measured on the board for 6 degrees, the control temperature θ8 remains at θ1. When the start switch 8 is pressed to restart, the operation starts from step 101 described above, and the same operation is repeated thereafter. In the flowchart of FIG. 3, the flow when the temperature control means is stopped is omitted.

By performing these operations described above, even if the user forgets to turn off the switch, the control temperature is automatically lowered to a low and safe temperature, thereby preventing dangerous situations such as burns or fire from occurring. This is possible.

Effects of the Invention As is clear from the description of the embodiments above, the present invention provides temperature detection means for detecting the temperature of a plate, temperature control means for controlling temperature at a plurality of temperature points, and control performed by the temperature control means. By providing a control temperature setting means for setting the temperature, a timekeeping means for starting time measurement from the time when the temperature control operation is started by the temperature control means, and a control temperature changing means for changing the control temperature by the temperature control means. Even if the user forgets to turn off the switch and leaves it unattended, the control temperature will automatically change to the lowest control temperature after a certain period of time, which prevents the user from getting unexpectedly burned and creating a dangerous situation such as a fire. It also prevents this from happening. In addition, its effects are significant, such as preventing unnecessary power consumption.

[Brief explanation of the drawing]

FIG. 1 is a 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 characteristic diagram, and FIG.
The figure is a flowchart, Figure 4a. b is a circuit diagram and a configuration diagram of a conventional electric hot plate control device. 6... Temperature detection means, 7... Temperature control means, 9... Control temperature setting means, 11...
...Time measuring means, 12... Control temperature changing means. Name of agent: Patent attorney Toshio Nakao, 1st person, 2nd person
Figure 3 Nominal diagram (b)

Claims (1)

[Claims] temperature detection means for detecting the temperature of the plate; temperature control means for controlling the temperature at a plurality of temperature points; control temperature setting means for setting the control temperature controlled by the temperature control means; and temperature control by the temperature control means. and a control temperature changing means that changes the temperature controlled by the temperature control means, and when the time measurement means measures time for a certain period of time, the temperature control means controls the temperature. A control device for an electric hot plate, characterized in that the control temperature is changed to the lowest control temperature by a control temperature changing means.