JPS6059693A - Temperature controller of electromagnetic cooking device - Google Patents

Abstract

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

Description

[Detailed description of the invention] (Technical field) The present invention relates to a temperature-side 1llll device for an electric cooker.

[Background technology]

In an electromagnetic cooker, when adjusting the temperature of the object to be cooked (hereinafter referred to as load), conventionally the load is placed on the surface of the cooker. A temperature control device is used that detects the temperature and controls on/off of the N source of the heating device based on the signal obtained thereby.

Generally, there is a proportional relationship between the weight of a load and its heat capacity.

Furthermore, for the supply of the same amount of heat, the heat capacity of the load and the rate of temperature rise (response) are inversely proportional.

The same can be said about the decrease in the temperature of the load.

Therefore, for the same temperature control system, when a load of small weight is applied, there is a problem that the system tends to overheat, and even after the temperature has stabilized, the temperature changes rapidly. Therefore, a temperature control device that can provide temperature stability and response of 1q regardless of the load l1ffi has been desired.

[Disclosure of the invention]

An object of the present invention is to provide a temperature control circuit for an electromagnetic cooker that meets the above requirements.

The hot water temperature control device for an N magnetic cooker according to the present invention inputs the output signals of the first temperature control circuit, the second temperature control circuit, and each of the above-mentioned temperature control circuits, and sends the output signals to the heating device. and an output control circuit that supplies signals for control.

The first temperature control circuit includes a humidity sensing element that can detect the temperature of the load;
It consists of a circuit that converts the signal from the humidity sensing element into a control signal related to the temperature of the load.

The second temperature control circuit outputs a control signal according to the weight of the load placed on the top play 1.

The output signals of the first and second temperature control circuits described above are applied to an output control circuit that controls the output of the heating device. The output control circuit controls the output of the heating device according to a predetermined procedure based on the above two signals.

The temperature control circuit of the electromagnetic cooker configured as described above controls heating of the load based on two parameters: the currently measured temperature of the load and the weight. As a result, it is possible to correct the response characteristics of temperature rise based on the weight of the load, and prevent overheating and sudden changes due to differences in load weight. Makes cooking possible.

[Excellent form for carrying out the invention]

Examples of the present invention will be described in detail below.

FIG. 1 is a structural diagram showing an embodiment of a temperature control device for an electromagnetic truer according to the present invention.

In the figure, 1 (the main body of the electromagnetic cooker, a container (pot, etc.) that stores the utensils to be cooked placed on the top plate 3)
It is heated by electromagnetic induction by a heating device 12 disposed within the main body 1. 17 is a temperature sensing element that detects the temperature of the load. Reference numeral 2 denotes a load member detection means, which employs a capacitive detection means composed of a movable part and a fixed part.

The movable parts are 1 to 3 to place the load.
It consists of an electrode A4 and a shaft 5.

The top plate 3 for carrying a load and the electrodes Δ4 are connected in parallel. The top plate 3, the electrode A4, and the shaft 5 can move vertically up and down as a unit.

The fixed part consists of the electric tffiB6, a fixed plate 7, and a fixed base 8. The electrode B6 is horizontally fixed by a fixing plate 7. Electrode A4 and M pole B6 are always held parallel to each other. ? A through hole is provided at the center of the lftff1B6 and the fixed plate 7 so that the shaft 5 can freely move up and down. The center of the fixed base 8 is provided with a recess so that the tip of the shaft 5 can be lowered to a predetermined position. The spring 9 has one end fixed to the shaft 5 and the other end fixed to the fixed base 8, and has elasticity to return the top plate to the uppermost position whenever no load is placed on the top plate.

The weight detection mechanism 2 described above, except for the electrodes A and B, is made of non-conductive material.

With this structure, when a load is placed on the top plate, the electrode A4 descends while remaining parallel to the electrode 86. The distance of descent is then proportional to the weight of the load. The distance between the two electric machines is reduced by the distance that the electrode Δ4 has descended.

Electrodes A and B form a capacitance.

The magnitude C of this capacitance is inversely proportional to the distance between the two electrode plates. This capacitance C is drawn out to the terminal 10 and used as a component of the second subtone circuit.

The structure for fixing one of the two parallel electrode plates and preventing the other from moving reversibly in the direction perpendicular to the electrode plate in conjunction with the movement of the 1 to 3-piece plates is not limited to the above, but various structures can be used. Is possible.

Figure 2 shows the electric power of the present invention! FIG. 1 is a circuit diagram showing an embodiment of a wetness control system for an i-cooker.

An electromagnetic heating device @12 for heating the load and an inverter 13 for supplying DC power to it are included in the main body of the electromagnetic cooker.

The output control circuit 14 performs on/off control of the inverter 13.

In the first temperature control circuit 15, a temperature sensing element 17 is mounted at a suitable location on the top plate 1, etc., and provides an output signal representing the temperature of the load to the control signal generation circuit 18. A reference signal representing a reference temperature preset by a setting device 20 is applied from a temperature setting circuit 19 as another input to the control signal generating circuit 18. Compare the two temperatures using the signal from 17 and the signal from temperature setting circuit 19,
A signal corresponding to the temperature difference is supplied to the output control circuit 14.

In the second temperature control circuit 16, the capacitance C formed by the N pole A (+5 J: and B) of the load weight detection mechanism (Fig. 1, 2) is drawn out by the 1110, causing oscillation It is used as an element of a tuned circuit that determines the oscillation frequency of the circuit 21.The output of the oscillation circuit 21 is input to the counter 22, and the counter 22 counts the oscillation frequency of the oscillation circuit 21.The oscillation frequency of the oscillation circuit 21 is determined by the capacitance C, so the scale value above represents the weight of the load placed on the top plate.

The count signal of the counter 22 is given to a control signal generation circuit 23. This circuit 23 sends a signal representative of the weight of the load to the output control circuit 14.

The output control circuit 14 transmits on/off control of the power supply of the heating device 12 using two signals supplied from the first and second temperature control circuits to adjust the temperature of the load to an optimum value. The signal is sent to the -r converter 13.

The capacitance C formed by electrodes A and B in this way
The frequency of the oscillation circuit 21 is determined by the counter 22.
Since the circuit for digital processing is simple, it is easy to manufacture and operates accurately.

In the above embodiment, a capacitance type was used as the load weight detection means, but the present invention is not necessarily limited to this. For example, the top play 1- can be elastically supported on a fixed base so as to be able to move up and down, and suitable means can be used, such as detecting this moving group using a variable resistance or an optical method.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram of an embodiment of the temperature control light main device of an electromagnetic cooker according to the present invention, and FIG. 2 is a circuit diagram thereof. 3... Top play 1., 4... First electrode plate, 6... Second electrode plate, 14... Output control circuit, 15 ...First temperature control circuit, 16...Second temperature control circuit, 17...Moisture sensing element, L...Load. Applicant NEC Home Elec 1-〇NICS Co., Ltd. Agent Patent Attorney Masu 1) Takeo

Claims (1)

[Scope of Claims] 1. A temperature control device for an electric cooker that adjusts the temperature of a load by controlling the output of a heating device that heats the load placed on a top plate, the temperature control device being a temperature-sensitive device. A first temperature control circuit that measures the temperature of the load using an element and generates a control signal according to the temperature, and a first temperature control circuit that detects the weight of the load placed on the top plate and generates a signal representing it. 2 temperature control circuit; and an output control circuit that receives output signals from the first and second temperature control circuits and generates a control signal for controlling the output of the heating device. Device.