JPS6343827Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a control device for a cooking device such as a toast or oven, and particularly relates to a control device for a cooking device that controls the focus when cooking continuously.

Conventionally, in this type of device, the time is controlled using a mechanical or electronic timer, but due to the influence of the temperature inside the cooker, the time for the first and subsequent cooking times is the same. Since the temperature is higher from the second time onwards, there is a tendency for the browning to become slightly darker, and there is a drawback that a constant browning cannot be achieved when cooking continuously.

The present invention has been made in relation to the above, and its purpose is to provide a control device for a cooking device that can obtain a constant degree of charring even when cooking continuously. To achieve this purpose, two capacitors are placed in parallel via a diode, one of which is equipped with a switch element, and the other is equipped with a temperature sensing element that detects the temperature equivalent to the temperature inside the cooker, and the other capacitor is equipped with a discharge prevention device. The circuits are connected to each other so that a constant focus is maintained regardless of the number of times the cooking is done.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. 1 is AC power supply, A, B
is its terminal, 3 and 4 are power switches operated by set switch 5, and switch 3 is connected to load 2.
The switch 4 is connected in series with a resistor 6, a diode 7, and a capacitor 8 to each terminal A, B.
connected to. Also, a latch circuit 9 is connected in parallel with the capacitor 8, and thereby the power switch 3,
4 opens and closes.

One side of the power switch 3 is connected to a capacitor 13 via a diode 10, a resistor 11, and a diode 12, and a constant voltage is obtained by a constant voltage diode 14 connected in parallel with the capacitor 13. The constant voltage is connected to a series circuit of a resistor 17, a variable resistor 18, a resistor 20, and a resistor 21, and a temperature sensing element 19 connected in parallel with the resistor 20 so that the voltage is divided, and the focus adjustment is determined. In addition to setting the voltage value, a variable resistor 1 is connected to the gate of the switch element 22.
One end of 8 is connected to supply that voltage. The temperature sensing element 19 is mounted at a position to detect a temperature corresponding to the temperature inside the cooking appliance (not shown). resistance 2
A voltage change of 1 is inputted to the base of a transistor 16 serving as a load through a resistor 15, and the collector thereof is inputted to a latch circuit 9.

Further, the voltage on the cathode side of the diode 10 is divided by a resistor 24 and a resistor 26. A capacitor 28 is connected from the midpoint through a diode 25 and a resistor 27 so as to be charged, and a capacitor 29 is connected to the capacitor 28 through a diode 30. One terminal of the capacitor 28 is connected to the anode side of the switch element 22 via the resistor 23, and its cathode side is connected to the terminal B. capacitor 2
9 is connected to a series circuit including a diode 31 and a resistor 34.

Further, the voltage on the anode side of the diode 12 is smoothed by a capacitor 37, and the voltage divided by a resistor 36 and a resistor 35 is connected to the cathode side of the diode 31 via a diode 33. These constitute a discharge prevention circuit 39 to prevent the capacitor 29 from discharging into the resistor 34. Also, diode 32
is provided as a bypass for discharging only the capacitor 28.

Next, the operation of the circuit of the control device configured as described above will be explained with reference to FIG.

When the set switch 5 is set, the coil of the latch circuit 9 is energized, the power switches 3 and 4 are closed and latched, and energization starts to be applied to the load 2. A pulsating current flows through the battery, and charging begins. Since the divided voltage of the resistor 36 and the resistor 35 is applied to the cathode side of the diode 31 via the diode 33, the voltage Vd becomes high level and reverse biases the diode 32. Therefore, the capacitor 29 does not discharge to the resistor 34, and the capacitors 28 and 29 are electrically connected in parallel, and the voltage Va has a potential difference of the forward voltage of the diode 30, as shown in FIG. It increases with almost the same voltage Vb.

On the other hand, a constant voltage obtained across the capacitor 13
Ve is divided by a resistor 17, a variable resistor 18, a resistor 20, a parallel combined resistor of the temperature sensing element 19, and a resistor 21, and a voltage Vc corresponding to the focus set is applied to the gate of the switch element 22. Therefore, after a certain period of time, the voltage Va across the capacitor 28
When the voltage reaches (Vc+Vt) ₁ (Vt is the gate voltage of the switch element 22), the switch element 22 is turned on and the capacitor 28 is discharged through the resistor 23. At the same time, the voltage Vc also decreases, and this signal change is detected by the resistor 15
amplified by a transistor 16 with a load of
Input to latch circuit 9. That is, when the input signal of the latch circuit 9 changes from the L level when the timer is set to the H level when the set time has elapsed, the coil in the latch circuit 9 is no longer excited, the power switches 3 and 4 are opened, and the latch is released. , load 2
energization is interrupted, and the toasting operation for timer time _T1 ends (first time of cooking).

In preparation for the next cooking, even after the power switch 3 is turned off, the voltage Vd of the capacitor 29 remains almost constant.
Since the potential drops to 0V, the voltage is reduced from _t1 through the diode 31 and resistor 34 as shown in Figure 2.
Although Vb gradually decreases, the voltage Va of the capacitor 28 is instantaneously discharged via the switch element 22 which is turned on, and reaches a value close to 0V at _t1 . That is, if the pause time after time _t1 is long, the discharge potential of Vb will drop, so as explained above, the timer will gradually return to the first timer time.

When the second cooking starts at time _t2 , when the set switch 5 is set in the same way as the first cooking, the power switches 3 and 4 are closed and power supply to the load 2 is started. However, since the capacitor 29 has a residual voltage of voltage Vb, the diode 25 is reverse biased, and the ripple current flowing through the resistor 27 charges only the capacitor 28 first. That is, until the time _t3 when the voltage Va reaches Vb + V _AK = Va (V _AK is the forward voltage of the diode 30), the cathode voltage Vd of the diode 30 becomes a high level voltage,
As this diode 30 becomes reverse biased, diode 25 also becomes reverse biased, so
The capacitor 29 is not charged and the Vb voltage between t ₂ and _{t 3} in FIG. 2 is approximately constant.

Next, when the voltage Va reaches the time _t3 when it becomes Vb+V _AK , the diode 30 becomes forward biased and the capacitor 29 also begins to be charged. For this reason t ₃
The voltage Va after that point will rise at the same speed as the first time. Furthermore, when the voltage Va of the capacitor 28 reaches (V _C +V _T ) ₁ (V _T is the voltage between the anode and the gate of the switch element 22) at t ₄ , the switch element is switched off in a slightly shorter timer time T ₂ than the first time. 22 is turned on, and the output signal of the transistor 16 is input to the latch circuit 9 in the same operation as the first time. Therefore, the coil in the latch circuit 9 is no longer energized, and the power switches 3 and 4 are turned off.
is opened, the latch operation is released, the current supply to the load 2 is interrupted, and the second toast cooking operation is completed.

Furthermore, when the third time is started from time _t5 , the set switch 5 is set in the same way as the second time, the power switches 3 and 4 are closed, and the power supply to the load 2 is started. If you continue to do it for the second time, the temperature inside the cooker will be higher than the second time,
If the same variable resistor 18 is set, the toast timer time will be almost the same as the second time, so the toast will become dark and burnt. However, since the temperature sensing element 19 is connected in parallel to the resistor 20, its resistance value decreases, and the timer time setting voltage decreases by that amount from (V _C +V _T ) ₁ to (V _C +V _T ) ₃ . It turns out.

Therefore, in the third operation, as shown in Figure 2, the potential (V _C +V _T ) is changed depending on the temperature inside the cooker, and the operation includes a rest period after operation, so the same operation is performed. Slightly shorter time than the second time T ₃
I will be working at

In other words, when toasting is done almost continuously from the first time (the cooker temperature is room temperature) to the third time, the toasting times are controlled according to the relationship T ₁ > T ₂ > T ₃ > T ₄ ... That will happen.

In this invention, a switch element is connected to one of two capacitors that are charged by a power supply, a temperature sensing element is connected to the gate of the switch element, and a discharge prevention circuit is connected to the other. In addition to recognizing the length of the rest time, it is also possible to detect the internal temperature of the cooker or a temperature equivalent to the same temperature using a temperature sensing element, and incorporate recognition of temperature rise into the control. Since it is corrected, even if you cook continuously,
Furthermore, even if cooking is performed intermittently, the result is a uniformly browned finish.

Note that the temperature sensing element may directly detect the temperature inside the cooking device, or may be placed anywhere in the space other than the inside of the cooking device corresponding to the same temperature.

[Brief explanation of the drawing]

FIG. 1 is an electrical circuit diagram of a control device for a cooking appliance showing an embodiment of the present invention, and FIG. 2 is a diagram showing the relationship between operating time and voltage of the main parts of FIG. 1. 1...Power supply, 3, 4...Power switch, 9...
Latch circuit, 19... Temperature sensing element, 22... Switch element, 28, 29... Capacitor, 39... Discharge prevention circuit.

Claims (1)

[Scope of utility model registration request] A capacitor 29 is connected to the capacitor 28 charged by the power supply 1 via a diode 30, and a switch element 22 is connected to the capacitor 28 to control a latch circuit 9 that opens and closes the power switches 3 and 4. A control device for a cooking appliance, characterized in that a temperature sensing element 19 is connected to the capacitor 29, and a discharge prevention circuit 39 is connected to the capacitor 29.