JPS5956627A - Boiling detecting device - Google Patents

Abstract

PURPOSE:To perform accurate boiling detection in spite of more or less of the water quantity by a method wherein a heat capacity is judged by measuring the time required for passing between two different temperature points, a time required for boiling is determined and a electrifying control due to said measured time is performed, when a water containing vessel is heated by a heat generating body. CONSTITUTION:When a water containing vessel 7 is heated by a heat generating body 8, at a start switch 12 is turned ON, a three terminal doublethrow thyristor 9 is turned ON by the control signal of a microcomputer 11 via a transistor 15. A heat generating body 8 is heated by the maximum electric power. Thereby, the temperature of the vessel 7 rises, the time required for temperature rising is calculated, that is, said time is calculated from the time that the temperature measured by a thermistor 10 reaches at the measurement starting temperature (about 70 deg.C), to the time that the temperature reaches at the measurement finishing temperature (about 80 deg.C), then the heat capacity is judged due to said calculating value. The time required for the boiling (delay time) is determined by said heat capacity, after the temperature reaches the designated temperature (about 90 deg.C), the electrifying is continued through the delay time, the boiling is performed, thereafter, the electrifying is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a boiling detection device for a thermal appliance such as an electric stove.

Conventional configuration and problems The conventional boiling detection device attempts to detect boiling using a thermostat installed at the bottom of the container, but the accuracy of the thermostat and the Due to variations in the temperature difference of the thermostat and various conditions, I had to judge that the water had boiled and squeezed once it reached 90 to 95' (-).

Purpose of the Invention In order to solve the above-mentioned drawbacks, the present invention determines the amount of water based on the time it takes to pass between two temperatures, and then delays boiling/boiling at this point after reaching a predetermined temperature for a time corresponding to the amount of water. The purpose is to detect boiling with high accuracy regardless of the amount of water in the container.

Structure of the Invention The present invention provides a heating system for heating a guest container containing water, and a hot water temperature detection system for detecting (1W1 degree) of the container.
; is provided, and the temperature above the temperature of this hot water temperature detector is
(, 'I' is measured by the temperature rise rate measuring means, and based on this measurement result, 'I'll is determined by the leisure publication means including the container and water. Based on the heat capacity, the delay time determining means determines the delay time according to the heat capacity, and after the temperature detector reaches a predetermined temperature of 1 degree regardless of the heat capacity, the delay time determining means determines the delay time. boiling determination means for determining that the water in the container has boiled when a delay time has elapsed;
Based on the output determined by the e-1 notification means that notifies the user of the fact that the
2 shots 47 mm (consisting of heating element energization control means for controlling energization to the body).

EXAMPLE An example of the present invention will now be explained with reference to the downstream drawings. 1 is an AC power supply, capacitor 2,
, the Zener tank auto 4, the resistor 5, and the first and sixth dies form a DC power source 7 for driving the circuit. 7 is a container with water stored in it. (A) means that if there is a large amount of water, it will become cold? When there are many 91 fish, (b) shows the case where the heat capacity is small. 8 is a heating element that heats the container 7, and 9 is a three-terminal bidirectional cyrisk that is a heating element control means, and controls the supply of electricity to the heating element 8. 1o is a thermistor which is a temperature detector and detects the temperature of the container 7.

11 is a one-chip microcombi-cooler with a CPU-
It consists of a ROM-RAM and an input/output port, and the input section includes the start switch 12 signal and thermistor 1.
It consists of a signal obtained by converting a temperature signal of 0 to a digital signal via an A/D converter 13, and the output section includes a light emitting diode 14, which is a heating alarm means, and a three-terminal bidirectional 141: thyristor 9. It consists of a transistor 15 that drives the gate.

Next, the operation of the boiling detection device configured as described above will be explained.

When the container 7 containing water is placed on top of the heating element 8 and the start switch 12 is closed, the ROMKa of the micro 2l/hi 11 is activated as shown in Fig. 2.
・(l) The boiling point 11 detection motion angle is started by the 1' block. At this time, the temperature of water in the container γ, i, 9.1, is ・, water (■, if there is a lot of water (■), then (a) is a small amount) Case (4, zu in Figure 3 regarding mouth LK).

When the maximum power is applied to the heating element 8 in step 2 of FIG. 2 without changing the temperature, the temperature of the container 7 increases. Next, Mr. 10's temperature is about to reach 111 degrees,
In step ■, 1, 'J iso. Then, the measurement start temperature (
For example, when 70γ゛) VC is reached, the first timer starts dividing in step ①, and reaches t in FIG.

Start measurement between 11 and 1. Next, in step 2, it takes 11J for the thermistor 10 to reach the measurement path r temperature (for example, s o '()), and when the thermistor 10 reaches the measurement path r temperature (for example, s o '()), the count of the first timer is finished in step 2, and tO is reached in step 2. The heat capacity is determined according to the temperature.As shown in Figure 3, in cases (a) and (b), the time it takes to heat at a constant 7 tt and pass between two predetermined temperatures (1o deg) (10 and t
If g) is measured, it will be longer in the case of (a), which has a large capacity, so of course to)t6 will be obtained.

Therefore, it is clear that 8 fraud fij can be determined from the (measurement) of to in step ■.Next, I+;'i of to
The delay times t1 and 1 . / is determined and stored in step (2).Next, since the heating operation is still continuing, wait until the thermistor 10 reaches a predetermined temperature (for example, 90 degrees) in step (2). next,
When the temperature exceeds 90 DEG C., in step (2), the heating element 8 is heated by the delay times t1 and t,/, which were previously determined in step (2), and the second timer counts and waits for the elapse of 1l-11. Then, the point at which the delay time t1 has elapsed is determined to be boiling in step Qφ. Of course t1\1. / . At this time, as shown in FIG. 3, since the temperature is delayed from 90° C. by a time corresponding to the heat capacity, the point in time when υ11 rises can be detected with high accuracy.

Next, in step 0, the light emitting diode 14 is turned on to notify that the boiling detection has been completed, and in step @, the electricity to the heating element is turned off (for example, stopped) to complete the boiling detection operation. do.

In the example in L, one set of foreign passengers is heated at 70°C to 80'C.
11 and after reaching 90℃, boiling was carried out with a delay of a predetermined time.
Even if you match 9o'<:), I: No.

-,! l/this, water in a container; explain the cases where there is a lot of tithe and the case where there is little [water) d is the same but the heat capacity is different 2); Depending on the judgment, I can be detected.

As is clear from the above description, the present invention can be used for a wide variety of containers and for different types of water, even if the temperature is different for foreign customers! Automatically determines the j1 rate and accurately boils 11ii,
change can be detected.

[Brief explanation of drawings]

, FIG. 1 is an electric circuit diagram of a boiling detection device showing one practical example of the present invention, FIG. 2 is a flowchart showing an example of a boiling detection program of the same boiling detection device, and FIG. FIG. 3 is a temperature characteristic diagram of main parts of the boiling detection device. 7 - Container, 8... Heating element, 9 - Three terminal bidirectional 1'1 Zyristor, 10... Thermistor, 1
1 microcomputer, 14... light emitting diode. 2nd 1 Fig. 3 1 Closing----1

Claims (1)

[Claims] a heating element that adds a container containing water;
Previous 1: Use a temperature detector to detect the temperature of the Iir container, and use the output of this temperature detector as an input signal to measure the bamboo ratio by 1 degree.'r)1. Parent 1.・Measurement means and this 11
M degree higher! Based on the number of til11 of the fixed stage, the heat capacity of the container including water: I) is 'I'
11, 5 determination means for '+1 heat Y≠, and this heat capacity identification means to determine/ξ heat capacity 7Jl; delay time determination means to determine the delay time table for I surface detection;
This delay lL'l°determination5. ! The output of the two means and the output of the temperature detector are used manually to determine whether the water in the container is N151 after the temperature detector reaches a predetermined quality after a time delay determined by the determining means. boiling determination means for determining that boiling is complete; /1Jli rise detection device consisting of a heating element flow control means for controlling the heating element flow.