JPS637677B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an electromagnetic induction cooking device.

Conventional devices are equipped with a small object detection circuit that detects the current flowing through the heating coil when a small object such as a knife, fork, or spoon is placed on top of it, and cuts off the current flowing through the heating coil when the current is small. This is an important safety device that prevents small items from heating up and causing burns if people accidentally touch them without realizing it. However, because of this safety device, even if you try to warm up small items such as canned drinks such as canned coffee, the small object detection circuit will work and there will be no way to warm them up. In view of this point, the present invention provides an electromagnetic induction heating cooker that can heat even small items with the conventional safety device attached, and that the safety device will not heat the small items if they are placed carelessly. . Embodiments will be described in detail below with reference to the drawings.

The drawing is a block circuit diagram showing one embodiment of the present invention. In the figure, 1 is a power supply, 2 is an input detection element, and the detection output thereof is inputted to a level detection circuit 4 via a rectifier circuit 3. A variable resistor 5 is used to set the level of the level detection circuit 4. 6 is a self-holding circuit to which the output of the circuit 4 is inputted. Note that the level detection circuit 4 does not output an output signal when the input is large, and outputs an output signal when the input is small. 7 is an inverter circuit, 8
9 is an oscillation circuit, 9 is an inverter device including the inverter circuit 7 and oscillation circuit 8, 10 is a heating coil, 11 is a cooking device to be heated such as a pot, 12 is an input adjustment coil, 13 is a timer/motor, and 14 is a timer/motor. Motor switch 15 is a normally closed timer switch.

In the above configuration, when the pot is normally turned on, the input power is large, the output of the input detection element 2 and the rectifier circuit 3 is also large, and the level detection circuit 4 does not emit a signal. Therefore, the self-holding circuit 6 does not operate,
The oscillation circuit 8 continues to oscillate, and the output from the inverter device 9 to the heating coil 10 continues. Here, even if the input to the heating coil 10 is reduced by the input adjustment coil 12, the setting variable resistor 5 of the level detection circuit 4 is linked, so the level detection circuit 4 still does not produce an output and the inverter device continues to output. .

Next, when heating small items such as canned drinks, the input power is very small and the output of the rectifier circuit 3 is also small, so the level detection circuit 4 generates a signal. Therefore, in a conventional heating cooker, a self-holding device works to stop the operation of the oscillation circuit 8 and the output of the inverter circuit 7, thereby stopping the heating of small items.However, in the present invention, the power source is a timer motor. 13 and the timer switch 14, and the normally closed timer switch 15 linked to this is inserted and connected to the line connecting the self-holding circuit 6 and the oscillation circuit 8.Then, set the timer to the time required to warm up the canned beverage. Once set, the timer switch 14 is turned on and the timer motor 13 is started, and the normally closed timer switch 15 is turned off and the output of the self-holding circuit is cut off, so that the oscillation circuit 8 is not prevented from oscillating. , the output of the inverter circuit 7 also never stops. The small items are therefore heated. When the set time has elapsed, the timer switch 14 turns OFF, 15
turns ON, and at the same time as the timer motor stops, the output of the self-holding circuit 6 is input to the oscillation circuit 8, and at the same time as the oscillation stops, the output of the inverter circuit 7 also stops, and heating of the small object ends.

As explained above, according to the present invention, by adding a timer for heating small items, it is possible to heat any small items that cannot be heated with conventional electromagnetic induction heating cookers, and the safety can be improved. The effect of further expanding the scope of use without any damage is significant. Also, since it uses a timer, it will automatically return to its original state once the small items have finished heating, so there is no risk of making a mistake.

[Brief explanation of the drawing]

The drawing is a block circuit diagram showing one embodiment of the present invention. 1... Commercial AC power supply, 2... Input detection element, 3... Rectifier circuit, 4... Level detection circuit, 5... Variable resistor,
6...Self-holding circuit, 7...Inverter circuit, 8...
Oscillation circuit, 10... Heating coil, 12... Input adjustment coil, 13... Timer motor, 14... Timer motor switch, 15... Normally closed timer.
Switch.

Claims (1)

[Claims] 1. An electromagnetic induction heating circuit is provided with a means for detecting the load state, a level detecting means for the detected signal, and a self-holding circuit, and the level detecting means adjusts the detected level in conjunction with the output adjusting means of the inverter. A variable induction heating cooker is equipped with a timer, and one end of a normally closed switch operated by the timer is connected to an output terminal of a self-holding circuit, and the other end is connected to an input terminal of an oscillation circuit. Electromagnetic induction heating cooker.