JPH0481090B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a bread maker that corrects the energization time so that the same color is obtained each time during repeated roasting.

Conventional configuration and its problems Conventionally, automatic toasters have utilized the charging and discharging of CR to turn on electricity only for a period of time that compensates for the temperature rise in the body. This will be explained below using FIG. Reference numeral 1 denotes a power supply, and when contact 2 is turned on, a voltage is applied to the heater 4 and energization is started. At the same time, smoothing capacitor 8 is charged to a constant voltage via resistor 6 and diode 7. The constant voltage is divided by resistors 10 and 11 to obtain a reference voltage V _r . On the other hand, charging of the capacitor 12 is started through the variable resistor 13 and the diode 14, and the capacitor voltage _Vc increases. When V _c becomes almost the same as V _r , PUT 9 performs a switching operation and turns on, the charge in capacitor 12 is discharged through resistor 15, and the thyristor 5 becomes conductive with the discharge current. When the thyristor 5 becomes conductive, the coil 3 is energized, the contact 2 which was mechanically latched to the closed contact is opened, and the heater 4 is de-energized. In this way, the time during which V _c rises to V _r becomes the time during which the heater 4 is energized. Furthermore, if the contact 2 is turned on again after the power is cut off to the heater 4 for a certain period of time [while the charge remains in the capacitor 12], the capacitor 12 will be recharged, but V _c will rise to V _r . The time required for roasting is reduced, the roasting time is shortened, and the degree of roasting is corrected. If we consider the case of short-time energization, the temperature rise characteristic of the container body is approximated to the voltage rise characteristic of the capacitor 12, so the temperature of the container body hardly rises due to its own heat capacity, but the capacitor voltage V _c will rise to some extent,
Subsequently, when roasting was performed for the second time, too much correction was applied, resulting in poor roasting quality.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and an object of the present invention is to provide a bread baking machine that can reproduce an appropriate degree of baking during repeated roasting.

Composition of the Invention In order to achieve the above object, the automatic roasting apparatus of the present invention includes a first temperature sensing means for measuring the atmospheric temperature inside the bread baking oven, and a position where the steam emitted from the bread hits when roasting the bread. a second temperature-sensing means attached to the temperature-sensing means, a comparison means for comparing inputs from the two temperature-sensing means, a delay means for delaying for a certain period of time after receiving the output of the comparison means, and this delay means. The configuration includes a load energizing means for controlling energization to the load based on the output of the energizer.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a circuit block diagram of the essential parts of a bread maker according to an embodiment of the present invention, in which 21 is a first temperature sensing means for measuring the atmospheric temperature inside the bread maker;
2 is a second temperature-sensing means installed at a position that is exposed to the steam emitted from the bread during roasting; 23 is the second temperature-sensing means;
Comparison means 24 compares the inputs from the two temperature sensing means 21 and 22; 24 is a delay means for delaying a certain period of time after receiving the output of the comparison means 23; This is load energization means that controls energization.

FIG. 3 is a vertical sectional side view of the bread maker in this embodiment, and FIG. 4 is a front view of the bread maker with the door open. The bread maker includes an outer body 31,
It consists of an inner body 32, a waste tray 33, a bottom plate 34, a left side plate 35 and a right side plate 36 which also serve as legs, and a door 38 with a door handle 37 on the front is attached so that it can be opened and closed freely. ing. An upper heater 39 and a lower heater 40 are installed inside the refrigerator, and a net 41 is placed between them, and the food 42 to be cooked is placed on top of the net 41. A temperature sensing element cover 4 is provided inside the rear compartment of the inner main body 32.
A first temperature sensing element 45 is installed inside the temperature sensing element cover 43, and a second temperature sensing element 46 is installed inside the temperature sensing element cover 44. Here, a hole is made below the temperature sensing element cover 44 so that the second temperature sensing element 46 is directly exposed to the steam emitted from the bread during bread roasting.

FIG. 5 is a circuit diagram of the bread maker in this embodiment, in which 51 is a power source, 52 is a contact, 53 is a heater consisting of the upper heater 39 and lower heater 40;
54 is a coil, 55 is a silicon controlled rectifier, 5
6 and 57 are comparators, 58 is an operational amplifier, ZD ₁ is a constant voltage diode, D ₁ is a diode, C ₁ and C ₂ are capacitors, VR ₁ is a variable resistor, and R ₁ to R ₁₃ are resistors. When the contact 52 is closed, the power supply 51 starts energizing the heater 53. On the other hand, when the contact 52 is closed, a DC power source of the following circuit is configured by a circuit including resistors R ₁₂ and R ₁₃ , a diode D ₁ , a constant voltage diode ZD ₁ , and a capacitor C ₂ . The first temperature sensing element 45 has a resistance between the DC power sources.
The second temperature sensing element 46 is connected in series with R ₁₀ and is also connected in the same way as the resistor R ₁₁ . These two voltage dividing points are connected to the minus input terminal and the plus input terminal of the operational amplifier 58 via resistors R ₈ and R ₉ , respectively. Also, the negative input terminal is resistor R ₆
The positive input terminal is connected to GND via a resistor _R7 . The output terminal of the operational amplifier 58 is connected to the plus input terminal of the comparator 57 in the next stage.
The voltage divided from the DC power supply by resistors R ₄ and R ₅ is input to the negative input terminal of the . The output terminal of the comparator 57 is connected to +V via the variable resistor VR ₁ , to GND via the capacitor C ₁ , and to the next stage comparator 56.
is connected to the positive input end of the This comparator 5
A divided voltage of the DC power supply by resistors R ₂ and R ₃ is inputted to the minus input terminal of 6, and the output terminal is connected to +V via the resistor R ₁ and to the gate of the silicon-controlled rectifying element 55 .

Next, the operation of the circuit will be explained. Contact 52 closes,
When the heater 53 starts to be energized, the bread inside the bread maker is heated. Generally, when bread is heated to a certain degree, it generates steam, and then it is baked by heating it for a predetermined period of time. Since the temperatures are the same, the two inputs of operational amplifier 58 are approximately equal. Since the predetermined voltage of the negative input of the comparator 57 is set higher than the output of the operational amplifier 58 at this time, the output of the comparator 57 is at a low level. The output of the comparator 56 at the next stage also becomes low level, and the gate of the silicon-controlled rectifier 55 is not triggered. As the current continues and steam begins to come out of the bread, a difference occurs between the input voltages of the operational amplifier 58. That is, since only the second temperature sensing element 46 comes into contact with water vapor and its temperature drops, the voltage at the plus input of the operational amplifier 58 becomes higher than the minus input, and the voltage at the plus input of the comparator 57 increases. this is resistance
When the predetermined voltage of the negative input of the comparator 57 determined by R ₄ and R ₅ is exceeded, the output of the comparator 57 becomes high level, and the output voltage of the capacitor C _{1 is increased through the variable resistor VR 1 .}
Charging will start. This charging voltage is determined by the comparator 56.
When the set value of the negative input of is exceeded, the comparator 56
output becomes high level, the gate of silicon-controlled rectifier 55 is triggered, excitation current flows through coil 54, contact 52 is opened, and heater 53
The power supply to is stopped.

To summarize, from the moment when the bread is heated and steam is emitted, and the second temperature sensing element 46 detects this, after a predetermined delay time by the delay circuit made up of the variable resistor VR ₁ and the capacitor C ₁ , the silicon controlled rectifier element 55 The gate of is triggered, and the energization of the heater 53 is stopped.

By detecting the degree of toasting of bread from the steam produced when the bread is baked in this way, bread with a good degree of baking can be obtained even after repeated roasting.

Effects of the Invention As explained above, according to the present invention, corrections were previously made during repeated roasting based on time information. Although there was a temperature difference inside the bread baking machine for the second time due to conditions such as heating, the electricity application time was uniform, so the degree of baking changed. By detecting the steam coming out and using this as the start timing, the electricity is stopped after a delay of a predetermined time, making it possible to more accurately reproduce the degree of roasting caused by repeated roasting.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of a conventional automatic toaster, Figure 2 is a circuit diagram of a conventional automatic toaster.
The figures are a circuit block diagram of the main parts of a bread maker according to an embodiment of the present invention, FIG. 3 is a vertical side view of the bread maker, FIG. 4 is a front view of the bread maker with the door open, and The figure is a circuit diagram of the bread maker. 21...First temperature sensing means, 22...Second temperature sensing means, 23...Comparison means, 24...Delaying means, 2
5...Load energizing means, 26...Load.

Claims (1)

[Claims] 1. A first temperature-sensing means for measuring the atmospheric temperature inside the bread baking machine; a second temperature-sensing means installed at a position where the steam emitted from the bread comes into contact with when roasting the bread; and the two temperature-sensing means. A bread baking device comprising a comparison means for comparing inputs from the comparison means, a delay means for delaying the output of the comparison means for a certain period of time, and a load energization means for controlling energization to the load based on the output of the delay means. vessel.