JPH0612683B2 - Electric hot plate controller - Google Patents

Description

TECHNICAL FIELD The present invention relates to a control device for an electric hot plate used in general households.

2. Description of the Related Art As shown in FIG. 3, the structure of a conventional electric hot plate is that the temperature of the plate 4 is detected by a temperature detecting means 2 such as a bimetal thermostat connected in series to an AC power source 1.
The contacts are mechanically opened and closed to control the energization of the heater 3,
It is configured to control the temperature of the metal plate 4 in which the heater 3 is embedded.

Problems to be Solved by the Invention However, the above-described configuration has a problem that if a power source is connected and a switch is turned on and left as it is, the user continues to operate forever unless the user turns off the power source. Therefore, there is a risk that the high temperature condition will be maintained and the operator may unknowingly touch it and get burned, or in the worst case, a fire may occur. There is also a problem that wasteful power is consumed forever.

In view of the above problems, the present invention prevents the risk of burns, fires and the like that the high temperature state does not last even if the user forgets to turn off the switch and leaves it unattended, and eliminates unexpected stop of power supply during use. With the goal.

Means for Solving the Problems In order to achieve this object, a controller for an electric hot plate according to the present invention includes a power control element for controlling energization of a heater and a plurality of control temperatures for controlling the power control element. It has a temperature control means having, a control temperature setting switch for setting the control temperature of the temperature control means, and a time counting means for starting time counting when the control temperature setting switch is operated, and the time counting means has the control temperature. Each time the setting switch is operated, the time measurement is restarted from the initial value, and the temperature control means stops the energization of the heater by the power control element when the time measurement means measures a certain time.

Operation With this configuration, the user can change the set temperature, and each time the control temperature setting switch is operated, the timekeeping means is reset and the timekeeping is started from the initial value, and cooking can be performed at the predetermined set temperature for a certain period of time. If the timekeeping means measures a certain time or more, that is, if the control temperature setting switch is not pressed and the setting is not changed for a certain time or more, the control operation of the power control element is stopped and the heater is not energized. Stop. This makes it possible to prevent the plate temperature from being maintained in a high temperature state.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.
The heater 3 is connected to the AC power supply 1 via a relay contact 5a of a relay 5 which is a power control element. Further, the relay 5 has a relay coil 5b, and when the relay coil 5b is energized, the relay contact 5a is closed. Reference numeral 6 denotes a temperature detecting element such as a negative characteristic thermistor, which detects the temperature of the plate in which the heater 3 is embedded. Reference numeral 7 is a temperature control means for inputting the output of the temperature detection element 6, which controls the opening / closing operation of the relay 5 based on a signal from the temperature detection element 6 to control the plate temperature at a constant level. It has multiple control temperatures. Also, the temperature control means 7
Is provided with a start switch 8 for starting the operation of and the control temperature setting switch 9 for setting the control temperature θ _s in the temperature control means 7. With this control temperature setting switch 9, θ _s = 80 ° C. in this embodiment. Two kinds of control temperatures of θ _s = 230 ° C. can be set. Each time the start switch 8 or the control temperature setting switch 9 is pressed, the time measuring means 10 resets the time T measured and starts time counting.

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

First, when the start switch 8 is pressed, the control temperature θ _s in the temperature control means 7 is initialized to 80 ° C. Next, at step 102, the time T in the time measuring means 10 is reset to start time counting, and the process proceeds to step 103. In step 103, if the time T measured by the time measuring means 10 is less than 60 minutes, the process proceeds to step 104, the plate temperature θ is detected by the temperature detecting element 6, and the plate temperature θ is set at the control temperature θ. compared with _s, theta <turns on the relay 5 at theta _s If step 106 turns off the relay 5 proceeds to theta ≧ theta _s If step 107 to stop energization of the heater 3. After that, the routine proceeds to step 108, where the time T of the clock means 10 is counted up every 1 second, and step 1
At 09, it is determined whether or not the control temperature setting switch 9 has been pressed. If not, the process returns to step 103, and the same operation is repeated. Step 11 if pressed
At 0, the control temperature θ _s is set to 230 ° C., the process returns to step 102, the time T of the time measuring means 10 is reset, and the time counting is started again. After that, the process proceeds to step 103. If the time T has been counted for 60 minutes or more in step 103, the process proceeds to step 111, the relay is turned off regardless of the plate temperature, and the relay control operation is stopped. If the time T is less than 60 minutes, the process proceeds to step 104, and the above-described operation is repeated. By performing these operations described above, even if the user forgets to turn off the switch, it automatically turns off,
Since the power supply to the heater 3 is stopped, it is possible to prevent the risk of burns and fire.

EFFECTS OF THE INVENTION As is apparent from the above embodiments, according to the present invention, the time measuring means measures the time from the initial value each time the control temperature setting switch for setting the control temperature of the temperature control means having a plurality of control temperatures is operated. When the user operates the control temperature setting switch to change the set temperature during use, the temperature control means stops energizing the heater when the time measuring means measures a certain time. Since the timekeeping means starts timing from the initial value, it is possible to perform cooking according to the set temperature for a certain period of time specified by the timekeeping means, so that the power to the heater is not stopped during use, and cooking is possible. By changing the set temperature according to the above, it can be used over a certain period of time specified by the timekeeping means, and when the user is away, control temperature setting Since the switch is not operated, power supply to the heater is stopped after a certain period of time, so that safety can be secured and wasteful power consumption can be prevented.

[Brief description of drawings]

FIG. 1 is a block diagram of a controller for an electric hot plate according to an embodiment of the present invention, FIG. 2 is a flow chart of the controller for an electric hot plate, and FIGS. 3 (a) and 3 (b) are conventional electric hot plates. It is a circuit diagram and a top view of a control device of a plate. 3 ... Heater, 5 ... Relay (power control element), 7 ...
... Temperature control means, 9 ... Control temperature setting switch, 10 ...
… Time keeping means.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuhiko Tanaka 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) Bibliography 61-124240 (JP, Y2)

Claims (1)

[Claims] 1. A power control element for controlling energization of a heater, temperature control means for controlling the power control element and having a plurality of control temperatures, and a control temperature setting switch for setting a control temperature of the temperature control means. , Has a timekeeping means for starting timekeeping when the control temperature setting switch is operated, the timekeeping means restarts timekeeping from an initial value each time the control temperature setting switch is operated, and the temperature control means A controller for an electric hot plate, wherein the power control element stops energization of the heater when the time measuring means measures a certain time.