JPS62129016A - Electric pot - 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 Field of Industrial Application The present invention relates to an electric water heater such as a jar pot for boiling water and keeping it warm in general households.

2. Description of the Related Art As shown in FIGS. 4 and 5, a conventional electric water heater of this type includes a cylindrical container 1 with a bottom, a heating element 2 for heating water contained in the container 1, and a heating element 2 for heating water contained in the container 1. , a first thermostat 3 installed at the bottom of the container 1 and connected in series with the heating element 2; and a first thermostat 3 installed near the heating element 2 and connected in series with the first thermostat 3. The second
a thermostat 4, an outer case 5 that covers the outer periphery of the container 1, and a lid 6 that covers the upper opening of the outer case 5;
It consisted of a water quantity display tube 7 communicating with the container 1 at the upper and lower portions and extending in the vertical direction. With this configuration, when there is water in the container 1, the temperature of the water is controlled by the first thermostat 3, while when there is no water in the container 1, the temperature of the water is controlled by the first thermostat 3, which is installed near the heating element 2. Generally, the second thermostat 4 would stop supplying electricity to the heating element 2 when the temperature reaches a high temperature. It has also been common to inform the user of the water level in the container 1 using the water level display tube 7. However, with this configuration, if the user turns on the water level display tube 7 without noticing that there is no water in the container 1, in order to detect that there is no water, the heating element 2 needs to be energized and the second It was necessary to reach a temperature at which the thermostat 4 would operate. Moreover, the second thermostat 4 was set at an operating temperature that would normally not operate when water was present, and the temperature was quite high. Furthermore, even if the second thermostat 4 operates, it does not specifically indicate that there is no water;
The user did not notice this until he noticed it by looking at the water quantity display tube 7.

Problems to be Solved by the Invention However, with such a conventional configuration, if a user mistakenly turns on electricity without filling the container 1 with water, it takes time to detect that there is no water. There were problems in that the container 1 would change color due to high temperatures in various parts, and the components of the heating element 2 would need to be highly heat resistant.

The present invention solves these problems and is capable of detecting that there is water in the container and stopping the power supply to the heating element, and also has a simple configuration and provides an easy-to-understand display for the user. The purpose is to provide electric water heaters.

Means for Solving the Problems In order to solve the above problems, the electric water heater of the present invention has the following features:
A cylindrical container with a bottom, a heating element that heats water contained in the container, a water volume display tube that communicates with the container and extends in the vertical direction, and a water volume display tube provided at the lower end of the water volume display tube, and a water level detection means that outputs a signal depending on the presence or absence of water at the lower end, and a boiling indicator lamp that lights up when water is being boiled;
It is constructed of a heat retention indicator lamp that lights up when water is being kept warm, and an indicator lamp control means that alternately lights the boiling indicator lamp and the heat retention indicator lamp depending on the output of the water level detection means.

Function According to the above configuration, if there is no water in the container, it is quickly detected and the boiling indicator lamp and the heat retention indicator lamp are immediately turned on alternately, thereby eliminating the need for extra display devices, etc. To easily notify a user that there is no water without adding anything, and therefore to provide a safe and easy-to-use electric water heater with a simple configuration.

EXAMPLE An example of the present invention will be described below with reference to FIGS. 1 to 3. In FIGS. 1 to 3, the same parts as in FIG. 4 shown in the conventional example are given the same numbers, and the explanation thereof will be omitted.

FIG. 1 shows a circuit diagram of an electric water heater in one embodiment of the present invention, and 8 is a microcomputer, and this microcomputer 8 is a CPU.

It is a so-called one-chip microcomputer consisting of ROM, RAM, input/output ports, etc.

9 is a temperature sensor that comes into contact with the container 1 shown in FIG.
This temperature sensor 9 is connected to an input port of the microcomputer 8 via an A/D converter 1o. As a result, the temperature signal from the temperature sensor 9 is converted into a binary code and read into the microcomputer 8.

Reference numeral 11 denotes an AC power supply. A series circuit of a heating element 2 and a relay contact 12 is connected to this AC power supply 11, and a transistor 1 is activated by a signal from an output port of a microcomputer 8.
By passing current through relay coil 14 through 3,
Opens and closes relay contact 12. 15 is an infrared LED, 16
is a phototransistor, and as shown in FIG. 3, this phototransistor 16 is installed at a position opposite to the water display tube 7, and emits infrared rays when the water runs out due to a float 17 floating on the water in the water display tube 7. is blocked. The output of the phototransistor 16 is connected to the input port of the microcomputer 8.

18 is a boiling LED for indicating boiling, and 19 is a heat retention LED for indicating heat retention, which are connected to the output port of the microcomputer 8. 20 is a DC power supply for operating the circuit described above.

Next, the operation of the electric water heater configured as described above will be explained.

FIG. 2 shows a flowchart of the program stored in the ROM in the microcomputer 8, and the operation will be explained according to the steps of the program shown in this flowchart. First, in step 1, it is determined based on the signal from the phototransistor 16 whether or not there is water. At this time, if there is water and the phototransistor 16 is turned on by receiving the light from the infrared LED 15, the process proceeds to step 2, in which it is determined whether the boiling mode is set, and the boiling mode is set. If not, in step 3 it is determined whether the temperature sensor 9 is higher than the heat retention temperature, and if it is higher than the heat retention temperature, the heating element 2 is turned off in step 4.
In step 6, only the heat retention LED 19 is turned on, and the process returns to step 1. Further, if the temperature sensor 9 is equal to or lower than the heat retention temperature in step 3, the heating element 2 is turned on in step 6, and it is determined in step 7 whether the temperature is higher than (heat retention temperature - 3)°C. In step 7, the temperature sensor 9 is (warming temperature - 3)℃
If the temperature is too high, proceed to step 5; if it is low, proceed to step 8, set the boiling mode, and return to step 1.

If the boiling mode is set in step 2, the process proceeds to step 9, in which it is determined whether the water is boiling, and if it is not boiling, in step 10, the heating element 2
is turned ON, only the boiling LED 1s is turned on in step 11, and the process returns to step 1. If the water is boiling in step 9, the boiling mode is canceled in step 12 and the process returns to step 1.

Furthermore, in step 1, there is no water in the container 1 and the infrared light
If the float 17 blocks the light from the ED 15 and the phototransistor 16 is turned off, proceed to step 13, turn off the heating element 2, and turn off the boiling LEDia and heat retention LED 19 by 0.2 in step 14.
The lights are turned on alternately every second to indicate that there is no water in the container 1, and the process returns to step 1.

In the above embodiment, the water level detection means was composed of the infrared LED 15, the phototransistor 16, and the float 17, but a method such as placing a magnet in the float and detecting with a reed switch may also be used. Any device may be used as long as it can detect that the water has run out and output a signal, and is not limited to the water level detection means of the above embodiment.

Effects of the Invention As described above, according to the present invention, if there is no water in the container, it is quickly detected and the boiling indicator lamp and the keep warm indicator lamp are immediately turned on alternately.
To easily notify a user that there is no water without adding an extra display device or the like, and therefore to provide a safe and easy-to-use electric water heater.

[Brief Description of the Drawings] Fig. 1 is a circuit diagram of an electric water heater showing an embodiment of the present invention, Fig. 2 is a flowchart showing an example of a program of the electric water heater, and Fig. 3 is a circuit diagram of the electric water heater. 4 is a side view showing a part of a conventional electric water heater in cross section, and FIG. 5 is an electric circuit diagram of the electric water heater. 1... Container, 2... Heating element, 7...
...Water level display tube, 8...Microcomputer,
12...IJI/-W point, 14...-Relay coil, 15...Infrared LED. 16...-Phototransistor, 17...Float, 18...Boiling LED, 19...
Name of agent for thermal insulation LED0 Patent attorney Toshi Nakao
1 other person's funeral and 2 illustrations
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Claims (1)

[Claims] A cylindrical container with a bottom, a heating element that heats the water contained in the container, a water volume display tube that communicates with the inside of the container and extends in the vertical direction, and a water volume display tube provided at the lower end of the water volume display tube. ,
and a water level detection means that outputs a signal depending on the presence or absence of water at the lower end, a boiling indicator lamp that lights up when the water is being boiled, a heat retention indicator lamp that lights up when the water is being kept warm, and an output of the water level detection means. An electric water heater comprising indicator lamp control means for alternately lighting the boiling indicator lamp and the heat retention indicator lamp.