JPH0126453B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a timer device for a toaster oven.

In conventional toaster ovens, when roasting toast, a timer device is used to set the roasting time. However, when making toast for the first time,
The internal temperature of the toaster oven is different when baking for the second time onward, so if you set the timer device for the same roasting time, the color will be darker from the second time onward. Therefore, in order to achieve the same browning color, the toasting time had to be shortened each time the toast was baked, which was inconvenient. In addition, in order to solve this problem, toaster ovens have recently appeared on the market that have a built-in timer device exclusively for toast roasting and are equipped with an independent power switch to shorten the toasting time from the second time onwards. , two timer devices are required: a timer device for purposes other than toast roasting and a timer device exclusively for toast roasting, resulting in high costs.

Therefore, an object of the present invention is to provide an oven that has a simple configuration, is inexpensive, has good operability, and is capable of performing automatic toast roasting that shortens the roasting time in accordance with the normal timer heating and rise in internal temperature. An object of the present invention is to provide a timer device for a toaster.

A toaster oven according to an embodiment of the present invention will be explained based on the drawings. In the drawing, 1 is a heater, 2 is a timer contact of a timer device, 3 is a timer motor that drives the timer device, and 4 is a changeover switch. Contact a is closed when toast is roasted, and contact b is closed otherwise.

Now, when the timer contact 2 is closed by setting the timer time with the timer device, AC100V power is supplied to the circuit shown in the drawing, and at the same time the heater 1 is energized, the capacitor 7 is charged through the resistor 5 and the diode 6. As a result, power is supplied to the astable multivibrator circuit 8 and it starts oscillating. The output of the unstable multivibrator circuit 8 causes the transistor 9 to repeatedly turn on and off. When transistor 9 is on, it short-circuits the output terminal of diode bridge 10, thereby driving timer motor 3. In this way, the timer motor 3 is operated intermittently in synchronization with the output of the unstable multivibrator circuit 8. Here, when the contact b of the changeover switch 4 is closed, the output of the unstable multivibrator circuit 8 oscillates at a constant cycle and a constant load time rate, so the timer motor 3
is driven at a constant operating rate. That is, it works as a normal timer device. And timer motor 3
When the heater 1 rotates by a predetermined angle, the timer contact 2 opens, the timer motor 3 stops, and the power supply to the heater 1 stops. Next, when contact a is closed, that is, in the case of toast roasting, the fixed resistor 11 determines the period of the unstable multivibrator circuit 8.
Instead, a thermistor 12 is connected as a temperature sensing element, so if this thermistor 12 is installed at a location that has a correlation with the temperature inside the refrigerator, the resistance value of the thermistor 12 will increase as the temperature inside the refrigerator increases. becomes smaller, and the on time of transistor 9 becomes longer.
The load time rate increases and the operating rate of the timer motor 3 increases. That is, as the internal temperature increases, the roasting time becomes shorter. Therefore, in the case of toast roasting, the degree of toasting will be the same for the first and subsequent toasts, and if the timer device is set at a fixed position, the bread will always be baked to the same brown color.

In this way, the toaster oven of this embodiment has a simple configuration (only one timer is required), is inexpensive,
It has good operability and can perform automatic toast roasting, which shortens the roasting time according to normal timer heating and rise in internal temperature.

Note that operability can be further improved by interlocking the changeover switch 4 with a time setting knob of a timer device.

As described above, the timer device of the toaster oven of the present invention includes a timer motor, a timer motor drive circuit that drives the timer motor intermittently, and a timer motor drive circuit that drives the timer motor intermittently. a temperature sensing element that adjusts the load time rate of the motor drive circuit; a fixed resistor that keeps the load time rate of the timer motor drive circuit constant regardless of the temperature inside the refrigerator; and one of the temperature sensing element and the fixed resistor. It is equipped with a selector switch for making selections, so it has a simple configuration, is inexpensive, and has good operability.Moreover, it can perform automatic toast roasting that shortens the roasting time according to the normal timer heating and rise in internal temperature. It has the effect of being able to.

[Brief explanation of drawings]

The drawing is an electrical circuit diagram of a toaster oven according to an embodiment of the present invention. 1... Heater, 2... Timer contact, 3... Timer motor, 4... Selector switch, 8... Unstable multivibrator circuit (timer motor drive circuit),
12...Thermistor (temperature sensing element).

Claims (1)

[Claims] 1. A timer motor, a timer motor drive circuit that drives the timer motor intermittently, and a temperature detection element that is included in the timer motor drive circuit and adjusts the load time rate of the timer motor drive circuit in response to the temperature inside the refrigerator. A timer for an oven toaster, comprising: a fixed resistor that keeps the load time rate of the timer motor drive circuit constant regardless of the internal temperature; and a changeover switch that selects either the temperature detection element or the fixed resistor. Device.