JPS595289B2 - oven toaster - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toaster oven capable of automatic roasting and open cooking of bread, etc., and in particular, after being used as a toaster or as an open oven, when used as a toaster, The objective is to provide an open 5 toaster that can always toast bread to the desired color regardless of the situation.

Conventionally, there are two types of devices for controlling the cooking time of toaster ovens: mechanical ones and electronic ones. The present invention is a toaster oven having an electronic timer 10 that takes advantage of the advantages of an electronic type, such as high precision, low cost, high reliability, and multifunctionality, and particularly pursues multifunctionality. In other words, a time difference is set between the first timer time and the subsequent timer time, and a correlation is established between the pause time width between the previous timer end time and the next timer start time, and the time difference described in the previous 15. is determined. When baking bread of the same size and number of pieces in a toaster oven, the temperature inside the toaster oven rises from the same temperature as room temperature the first time the bread is toasted, but from the second time onwards When roasting bread for the first time, the temperature inside the container is above room temperature due to the heat capacity of the container, so if the first roasting time and the second and subsequent roasting times are the same, the second and subsequent roasting This will make the bread darker. 25 Furthermore, it is clear that the shorter the time from the completion of the first bread roasting to the start of the second bread roasting, the greater the difference in the degree of bread baking.

In addition, in places where bread is roasted after open cooking,
Since the internal temperature is high, it is difficult to determine the roasting time that will give the desired degree of toasting of the bread 30. The present invention solves the drawbacks of the toaster oven described above, and embodiments of the present invention will be described below with reference to the accompanying drawings.

In Fig. 35, 1 is an AC power supply, and a parallel circuit of a first open/close switch 2 for open cooking and a second open/close switch 3 for a toaster is connected to this AC power supply, and a heater is connected to this parallel circuit. 4 are connected in series, and the AC power supply 1, a parallel circuit of the first on-off switch 2 and the second on-off switch 3, and the heater 4 constitute a closed circuit.

A series circuit of a resistor 5, a diode 6, and a capacitor 7 is connected in parallel to the heater 4. In this series circuit,
The AC power supply voltage is half-wave rectified by the diode 6 and smoothed by the capacitor 7, so that the voltage between the terminals of the capacitor 7 becomes the DC power supply voltage. A Zener diode 8 is connected in parallel to this capacitor 7 so as to have a polarity opposite to that of the diode 6, and a resistor 9 and a resistor 10 are connected in series, and a diode 11 and a resistor 1 are also connected in series.
2, a resistor 13, and a capacitor 14 connected in series are connected in parallel. Note that the voltage between the terminals of the capacitor 7 is determined by the Zener voltage level of the Zener diode 8. 15 is another Zener diode, which is connected in parallel to the resistor 13 so as to have the same polarity as the diodes 6 and 11.

Reference numeral 16 denotes a three-terminal switching element (hereinafter referred to as PUT), the gate electrode of which is connected to the connection point between resistors 9 and 10, the anode electrode connected to the connection point of resistors 12 and 13, and the cathode electrode connected to the connection point of resistor 17. The AC power source 1 is connected to one end of the AC power source 1 via the AC power source 1.

The heater 4 also includes a relay coil 18 and a thyristor 19.
The series connected bodies are connected in parallel, and the relay coil 18
When current flows through, toaster open/close switch 3 turns 0FF.
be done. The gate electrode of thyristor 19 is connected to the cathode electrode of PUTl6. In the above configuration, a case will be described in which the toaster oven of this embodiment is used as a toaster.

First, when the on-off switch 3 for the toaster is turned ON, current flows from the AC power supply 1 to the heater 4, and roasting of bread, etc. is started.

The open/close switch 3 is self-held. Open/close switch 3
0N, a DC voltage is generated between the terminals of the capacitor 7. This DC voltage is determined by the Zener voltage level of the Zener diode 8, and is resistance-divided by a resistor 9 and a resistor 10, and is the gate voltage V of PUTl6. Set. On the other hand, a charging current flows to the capacitor 14 through the diode 11, the resistor 12, and the resistor 13, and the voltage between the terminals of the capacitor 14 gradually increases.

Now, when the voltage c between the terminals of the capacitor 14 reaches the gate voltage VG of the PUTl6, the PUTl6 enters the ON state, and the charge stored in the capacitor 14 is discharged through the Zener diode 15 and the resistor 13. If the operating resistance of the Zener diode 15 is extremely smaller than the resistance value of the resistor 13, most of the charge in the capacitor 14 is discharged through the Zener diode 15, but eventually the voltage across the terminals of the capacitor 14 becomes equal to the Zener voltage of the Zener diode 15. When the voltage becomes lower than the level Vz, the subsequent discharge occurs through the resistor 13. Also, PUTl6 is 0
When it is N, a current flows to the gate electrode of the thyristor 19, the thyristor 19 becomes 0N, a current flows to the relay coil 18, and the on/off switch 3 is turned OFF, and the roasting of bread, etc. is completed. Next, we will discuss the charging and discharging process of the capacitor 14.
This will be explained with reference to the figures. T is the time when the open/close switch 3 is turned 0N.

Then, the capacitor 14 is gradually charged and PUTl
The time when the gate voltage VG of 6 is reached is defined as t1. Time t1
When this happens, PUTl6 becomes 0N, and the voltage Vc between the terminals of the capacitor 14 is equal to the Zener voltage Vz of the Zener diode 15.
After that, the discharge is performed slowly through the resistor 13. Furthermore, at time t1, the thyristor 19 turns ON and the on/off switch 3 turns OFF, so the capacitor 7
is discharged, the potential of the gate electrode of PUTl6 becomes zero potential, and the charge in the capacitor 14 is transferred to the resistor 13, PUTl6
The discharge through the anode, cathode, resistor 10, etc. is sustained. On the other hand, the thyristor 19 also switches to the open/close switch 3.
When becomes 0FF, it returns to the 0FF state. Next, at time T2, when the on/off switch 3 is turned ON again, the capacitor 1
4 charging will be performed. In this case, the voltage A still remains between the terminals of the capacitor 14, and there is still time (T3-T2) until time T3 when the voltage VG is reached again.
is the charging time of the capacitor 14 (t
11TO). Note that this time difference is a function of the non-energization time (T2-t1) of the heater 4. Therefore, resistor 13, resistor 9, resistor 10, Zener diode 15
If you set the constant according to the shape of the toaster oven and the capacity of the heater 4, the roasting time will be corrected as described above, and even if you roast bread etc. continuously, the same degree of baking will be achieved. You can do it as you like. Next, the case of roasting bread etc. after cooking in an oven will be explained with reference to FIG.

First, time T.

When the oven open/close switch 2 is turned ON, the voltage Vc between the terminals of the capacitor 14 reaches the gate voltage VG of the PUTl6 at time t/, as in the case of bread roasting. At time t/, PUTl6 becomes 0N, and capacitor 14
The inter-terminal voltage Vc is discharged to the Zener voltage Vz of the Zener diode 15, but since the open/close switch 2 remains in the 0N state, the valley current of PUTl6 becomes small.
PUT16 becomes 0FF again. Therefore, capacitor 1
The inter-terminal voltage Vc of No. 4 starts to rise. The above operations are repeated and when the oven cooking is completed, the open/close switch 2 is turned off manually or by a mechanical timer such as a wind-up type at time t'3. At this time, the capacitor 7 is discharged, the gate voltage VG of PUTl6 decreases, and the
Tl6 turns ON, and the voltage Vc between the terminals of the capacitor 14 is discharged to the Zener voltage Vz of the Zener diode 15. After this, the capacitor 14 is
The voltage c between the terminals of the capacitor 14 is gradually discharged, and when roasting bread etc. after cooking in the oven, when the on-off switch 3 for the toaster is turned ON at time t (the voltage Vc between the terminals of the capacitor 14 becomes the voltage This means that the charging time for bread, etc. is shortened by the charging time up to this voltage VA'.As is clear from the above explanation, according to the present invention, bread When continuously roasting bread, etc., or roasting bread, etc. after cooking in an oven, the degree of toasting of the bread, etc. can always be kept constant.

[Brief explanation of the drawing]

Figure 1 is an electric circuit diagram of a toaster oven showing an embodiment of the present invention, Figure 2 is a voltage-time characteristic diagram between capacitor terminals during continuous roasting in the toaster oven, and Figure 3 is oven cooking in the toaster oven. FIG. 3 is a voltage-time characteristic diagram between capacitor terminals during roasting. 2, 3... Open/close switch, 4... Heater, 13... Resistor, 14... Capacitor, 15... Zener diode, 16・・・・・・
...Three-terminal switching element.

Claims (1)

[Claims] 1. A parallel circuit in which a first open/close switch and a second open/close switch are connected in parallel, a heater connected in series to this parallel circuit, and a CR timer circuit consisting of a capacitor and a resistor that are charged by the voltage between the terminals of this heater. a first discharging circuit that discharges the charging voltage of the capacitor to a second constant voltage lower than the first constant voltage when the charging voltage of the capacitor reaches a first constant voltage; a second discharging circuit that discharges the charging voltage of the capacitor according to a predetermined discharge time constant after the capacitor is discharged to a second constant voltage; An on-off switch opening circuit that detects this and opens only one of the first on-off switch and the second on-off switch.