JPS6260524A - Rice coker - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a rice cooker configured to perform timer rice cooking using a rice cooking control circuit.

[Technical Preface of the Invention] Conventionally, in this type of rice cooker, the current time and cooking completion time on a digital display system are set by manually operating an automatic reset button switch, and the time for timer rice cooking is set. Those who do this are provided.

[Background art problem table] However, in such a conventional configuration, the time in 10 minute increments is advanced by 10 minutes by pressing the button switch once, or intermittently by 10 minutes by continuing to press the button switch. This is a time setting configuration that advances in steps. Therefore, there is a drawback that it takes time to advance the time from the reset time to the desired time, and the operation is troublesome. In particular, if you accidentally exceed the set time, you will have to start over from the reset time.
It was not easy to use.

[Object of the Invention] The present invention has been made in view of the above points, and its object is to provide an easy-to-use rice cooker that can easily and quickly set the rice cooking time using a timer. It is in.

[Summary of the Invention] The present invention provides a variable voltage generation circuit having a manually operable variable resistor, and converts an analog voltage signal outputted from the variable voltage generation circuit into Δ/D to determine the timer rice cooking time. The feature is that it is configured so that settings can be made.

[Embodiments of the invention] An embodiment of the present invention will be described below with reference to the drawings.

First, in FIG. 1 showing the circuit configuration, 1 is a microcomputer corresponding to a rice cooking control circuit, which has a timekeeping function using, for example, an AC power frequency. Reference numeral 2 denotes a four-digit seven-segment light emitting diode, and the cathode side of each digit is connected to multiple output terminals R to R3 of the microcomputer 1 via an inverter circuit 3, respectively.

A high level scan pulse is output to each of the output terminals Ra to R3 of the microcomputer 1, and the light emitting diode 2 is dynamically illuminated. Reference numerals 4 and 5 are a current time display mode switch and a cooking completion time display mode switch, respectively, which are self-reset type bush switches, and are connected to the output terminal Ro and input terminal of the microcomputer 1, respectively. connected between.

The input terminals 1 and 2 are always maintained at a low level by a pull-down resistor 6. Reference numerals 7 and 8 denote a cancel switch and a rice-cooking star 1 switch, both of which are self-reset type bush switches, and are connected between the output terminal R1 of the microcomputer 1 and the input terminal 1 and 2, respectively. There is. Reference numeral 9 denotes a variable voltage generation circuit for setting the current time, which consists of a Zener diode 10 with the polarity shown and a resistor 11 connected in series between the A/D conversion input terminal At of the microcomputer 1 and the ground line. A series circuit consisting of a manually operable variable resistor 12 for setting the current time and a resistor 13 is connected in parallel with the Zener diode 10, and the intermediate connection point between the variable resistor 12 and the resistor 13 is connected to A of the microcomputer 1. /D conversion input terminal V
It is connected to REFI.

As a result, the A/D conversion input terminal Δ1. An analog voltage signal va obtained by dividing the Zener voltage of the Zener diode 10 by a variable resistor 12 and a resistor 13 is applied between VREFI. Reference numeral 14 denotes a variable voltage generation circuit for setting the cooking completion time.
Conversion input terminal A2. It is connected to VREF2 and the ground line, respectively, in the same way as the variable voltage generation circuit 9 for setting the current time. As a result, A/D conversion input terminal Δ2. vREF
An analog voltage signal vb obtained by dividing the Zener voltage of the Zener diode 15 by a variable resistor 18 and a resistor 17 is applied between the two. The microcomputer 1 has A/D conversion input terminals A1. A function to A/D convert the analog voltage signal Va applied between VREFI and set the current time as a digital value according to the analog voltage signal Va, and an analog voltage signal applied between A/D conversion input terminal A2 and VREr2. It is provided with a function of A/D converting the voltage signal Va and setting the cooking completion time as a digital value corresponding to the analog voltage signal vb.

Next, the operation of this embodiment will be explained. This should make the functional configuration of the microcomputer 1 more clear. First, when the current time display mode switch 4 is pressed, a high level pulse is input to the input terminal 2 of the microcomputer 1 . Thereafter, when the variable resistor 12 for setting the current time is manually operated by rotating the operation knob 19 of the operation panel shown in FIG. An analog voltage signal Va corresponding to the rotation angle of
It is input between Fi. This analog voltage signal ■a is A/D converted according to the A/D conversion program preset in the microcomputer 1, and the current time according to the pre-conversion analog voltage signal ■a is determined by the converted digital signal. As well as being set to
The time is displayed on the light emitting diode 2. Next, when the cooking time display mode switch 5 is pressed,
A high level pulse is input to the input terminal of the microcomputer 1. Thereafter, by rotating the operation knob 20 of the operation panel shown in FIG.
When is manually operated, an analog voltage signal @vb is sent from the variable voltage generating circuit 10 to the A/D conversion input terminals A2 and V R of the microcomputer 1 according to the rotation angle of the operating knob 20.
It is input between EF2. This analog voltage signal Vb is A/D converted according to an A/D conversion program set in advance in the microcomputer 1, and the post-conversion digital signal sets the cooking completion time in the microcomputer 1 according to the analog voltage signal vb before conversion. At the same time, that time is displayed on the light emitting diode 2 instead of the current time. When the current time and cooking completion time are set in the microcomputer 1 as described above and the rice cooking start switch 8 is turned on, the time difference between the cooking completion time and the current time is determined according to the timer rice cooking program preset in the microcomputer 1. is calculated and displayed on the light emitting diode 2 as the remaining time until the rice cooking is completed, and the standby time is calculated by subtracting the time required to complete the rice cooking operation from the time difference. After this waiting time has elapsed, the rice cooking operation is started. The rice cooking operation is performed according to a well-known rice cooking program preset in the microcomputer 1 by turning off electricity to a rice cooking heater (not shown) while detecting the preparation of the pot.

In addition, in the variable voltage generating circuit 9, for example, the Zener diode 10 may have a Zener voltage of 5 Ω, the variable resistor 12 may have a resistance value of 0 to 50 Ω, and the resistor 11 may have a resistance value of 0 to 50 Ω.
A case will be described in which the resistor 13 is configured to have a resistor of 1Ω and a resistor 13 of 5Ω. In this case, the Zener voltage 5■ across the Zener diode 10 is controlled by the variable resistor 12 (O~
Since the voltage is divided by the resistor 13 (5KO) and the resistor 13 (5KO), a variable voltage of 0 to about 4.5Ω is generated across the variable resistor 12, and the A/D conversion input terminals A1 and V of the microcomputer 1 are An analog voltage signal Va of 0 to 4.5V is input to REF1. Therefore, as an A/D conversion program set in the microcomputer 1, for example, in the case of 8-bit A/D conversion, it is possible to digitize 2 to the 8th power, that is, 256 divisions, so the voltage range is from 0 to 4.5V. By dividing the signal with a resolution of approximately 20 mV, it is possible to set the A/D conversion to a digital signal for the current time divided into 24 hours every 10 minutes.

According to this embodiment having such a configuration, the current time and the cooking time can be set by rotating the operating knob 19 for setting the current time and the operating knob 20 for setting the cooking time in the direction of the arrow or in the direction opposite to the arrow. Therefore, the rice cooking time can be set more quickly and easily than the conventional timer. In particular, if a desired time is incorrectly set, the time can be corrected much more easily than in the past.

In addition, in the above embodiment, the current time and the cooking completion time are set as the setting time for timer rice cooking.
There is no need for the user to count the remaining time, improving ease of use. However, the present invention is not limited to this, and the user may set the waiting time until the rice cooking starts. Furthermore, it is not necessary to use the microcomputer 1 having an A/D conversion function, but a microcomputer without this function may be used and an A/D converter may be externally attached.

[Effects of the Invention] As is clear from the above description, the present invention provides a variable voltage generation circuit having a manually operable variable resistor, and converts the analog voltage signal output from the variable voltage generation circuit into an A/
Since the time is set by D conversion, the time for timer rice cooking can be set easily and in a short time, resulting in excellent practical effects such as improved usability.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a circuit diagram of the main part, and FIGS. 2 and 2 are front views of the operation panel. In the drawing, 1 is a microcomputer (rice cooking control circuit),
'9.14 is a variable voltage generation circuit for setting the current time and the finished cooking time, 12.18 is a variable resistor for setting the current time and the finished cooking time, respectively, and Va and Vb are analog voltage signals. Applicant Toshiba Corporation Figure 1

Claims (1)

[Claims] 1. In a rice cooking control circuit with a timer function that performs timer rice cooking, a variable voltage generation circuit having a manually operable variable resistor is provided, and an analog voltage signal output from this variable voltage generation circuit is used. A/D
A rice cooker characterized in that the rice cooker is configured to set a time for timer rice cooking by converting the rice cooker.