JPH0272579A - Controller for heating element of electric heater - Google Patents

Abstract

PURPOSE:To make it possible to obtain comfortable heating and power saving effect by installing a pair of electrode lines as a person detection means in a main body, and catching the change of oscillation frequency by an oscillation circuit so as to detect the existence of a human body to control the heating of a heater. CONSTITUTION:A pair of electrode lines 21 and 22 as a person detection means is installed in a main body 1 equipped with a heater 6 so as to constitute an oscillation circuit 3 which bears load between these electrode lines 21 and 22. And by catching the change of frequency by the change of capacitance at the oscillation circuit 3 which arises by the deference of whether there is a person or not in the main body 1, the heating control of the heater 6 is done. Hereby, it reacts sensitively to whether there is a person or not, so the operation is steady and person detection with high reliability becomes possible, and comfortable heating and power saving effect can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to electric heating appliances such as electric carpets, electric blankets, and electric sheets, in which a signal line is attached to the main body of the electric heating appliance, and a high-frequency current is applied to the signal line. The present invention relates to a heating element control device for an electric heating appliance that detects whether there is a person in the main body by circulating current and controls the heating of the heater of the electric heating appliance.

Conventional technology Conventionally, this type of heating element control device was disclosed in Japanese Patent Application Laid-Open No.
No. 383 (hereinafter referred to as A), JP 60-129538
No. (hereinafter referred to as B), Japanese Patent Application Laid-open No. 138338/1983 (hereinafter referred to as C), etc. have been proposed.

In A, a first signal line is arranged around the main body of the electric heating appliance, and a second signal line is arranged in the center thereof, and both signal lines are covered with the electric heating appliance. It has a structure that exhibits a predetermined impedance change between the sensing object (person) and the sensing object when it is present and when it is not present, and furthermore, both signal lines have different impedances depending on the presence or absence of the sensing object. It is configured to be connected to circuit means that detects a difference in impedance change and controls the heat generation operation of the electric heating appliance based on the detected output.

In addition, in B, there is a detection means for detecting the presence or absence of a human body (object to be detected) based on a change in impedance of a signal line arranged on the main body of the electric heating appliance, and a detection means for detecting the presence of a human body (object to be detected) by detecting the presence of a human body (object to be detected). The device is configured to include a control means for controlling the supply of electricity to the body, and a reduction means for reducing the influence of ground impedance of the detection means.

Furthermore, C has a main body consisting of a person detection means whose physical quantity changes when a human body is placed thereon, and one heating element, and a body that changes whether or not a human body is placed thereon depending on the change in the physical quantity of the person detection means. and a control section that controls the temperature of the main body using a temperature setting means when the main body is placed, and controls the temperature of the main body so that the control temperature is lower than the control temperature when the main body is not placed.

In A and B, the means for detecting the presence or absence of a person is configured to use a signal line attached to the main body, and detect by changing the impedance of the signal line, which changes depending on the presence or absence of a person. This is a detection means that uses changes in capacitance (impedance) between the ground side of the electrical circuit that makes up the circuit and the signal line. The detection characteristics of the detection means for detecting the presence or absence of a person vary significantly depending on changes in the humidity of the electric heating appliance itself and differences in the ground capacity of the installation location, making it difficult to accurately detect the presence or absence of a person. A first signal line and a second signal line are provided, and the presence or absence of a person is detected based on the difference in impedance change between the two. In B, means for reducing the influence of the ground capacitance of the signal line is also used, such as attaching a conductive member such as aluminum foil to the floor side of the electric heater body.

In C, a means for detecting a single person is used that changes the physical quantity between the electrodes according to the pressure, and the main body is controlled so that when no human body is placed, the control temperature is lower than the control temperature when a human body is placed. A feature of this invention is that temperature control is performed.

Problems to be Solved by the Invention The above heating element control device had the following problems.

(1) The detection characteristics of the human body detection means in A and B are affected by changes in the humidity of the electric heating appliance body and differences in the installation location. In order to avoid this, it is necessary to have a means to reduce the influence of the ground impedance of the signal line attached to the main body. Incidental measures such as the combined use of other methods are indispensable, which increases costs.

(2) The human detection means in C cannot distinguish between a human body and an object, and when a kotatsu, table, etc. is placed on the electric heating appliance, it causes a malfunction, and is not practical.

(3) As the control means for the heating elements in A and B, an embodiment is shown in which the power supply to the heating elements is controlled simultaneously based on the output of the one person detection means. Errors cannot be identified, and the reliability is poor.Furthermore, even if you leave your seat for a short time, the energization control of the heating element immediately responds, causing the main body temperature to drop, which is not desirable for comfortable heating.

(4) As the heating element control means in C, A and B
Similarly, the output of the human detection means is used to control the energization of the heating element at the same time, but in this case, the proposal is to make the control temperature in the state where no human body is placed lower than the control temperature in the state where the human body is placed. It is passive in terms of avoiding unnecessary power consumption, and has little power saving effect.

(5) When preheating an electric heating device to a predetermined temperature, there is often no one person sitting on the electric heating device.

In this case, C is not preferable in terms of comfortable heating because it is preheated at a temperature lower than the predetermined temperature. or.

In the cases A and B, the person detection means outputs an output during preheating, which may cause a problem in that the preheating is interrupted.

Means for Solving the Problems The present invention uses a person detection means for detecting whether or not a person is present in the main body of an electric heating appliance, and controls the heating of a heater provided in the main body, in which a pair of electrodes are used as the person detection means. A wire is attached to the main body, and the detection circuit is an oscillation circuit whose load is between the electrode wires, and the oscillation circuit captures changes in the oscillation frequency to detect and output the presence or absence of a human body, A microprocessor is used as the control circuit, and after recognizing the first wave OFF of the heater, it operates a high-frequency oscillator, reads the output of the detection circuit, counts the number of outputs, and satisfies predetermined requirements. The control circuit is configured to start a timer function when the number of outputs is obtained, and turn off the power to the heater after a predetermined time has elapsed.

As the operator detection means, a pair of electrode wires serve as signal wires. As a detection circuit, an RC oscillation circuit is constructed by the capacitance C between the electrode wires and a fixed resistor R to detect the presence or absence of five people.If there are six people, the C component is detected by the capacitance of the human body. increases, and the oscillation frequency changes compared to when no one is present, so this is detected and output. In cases A and B described in the prior art section, the presence or absence of a person was detected by the change in capacitance between the ground side of the electric circuit constituting the detection circuit and the signal line, so the ground capacitance of the signal line was However, in the present invention, since this is performed between a pair of electrode wires, the capacitance between the electrode wires is dominant, and the influence of the ground capacitance of the electrode wires can be suppressed. Furthermore, by applying the frequency obtained by the RC oscillation circuit to a pair of LC resonant circuits and satisfying a certain resonance condition, a significant difference between the presence and absence of a person becomes clear, and a highly reliable detection circuit can be obtained.

In the control circuit, the detection circuit is driven after recognizing the first wave OFF of the heater to reduce the influence of moisture between the electrode wires, and to prevent the human detection means from responding until preheating is completed. This is to maintain comfortable heating.

The number of outputs from the detection circuit is counted, and the timer function is started when the number of outputs that satisfies the predetermined requirements is obtained because the human detection means responds hypersensitively to the movement of the human body.
This is to prevent the temperature of the main body from dropping when you leave your seat for a short time, thereby impairing the comfortable heating performance.

Embodiment FIG. 1 shows an outline of a heating element control device for an electric heating appliance according to an embodiment of the present invention.

In the figure, reference numeral 1 denotes the main body of the electric carpet.A heater wire (not shown) is attached to the main body 1, and a person can sit on the main body 1 to keep warm. Reference numeral 2 denotes a signal line of the human detection means, and a pair of parallel electrodes are arranged inside the main body. The signal on the signal line 2 is inputted to the control circuit 5 via the oscillation circuit 3 and the detection circuit 4, and controls the heating of the heater 6. The detection circuit 4 applies the frequency change caused by the oscillation circuit 3 to the LC resonance circuit and converts it into a voltage change.
It detects whether there is a person on the main body 1 or not, and outputs it to the control circuit 5.

FIG. 2 shows the configuration of the control circuit 5 in FIG. 1.

In the figure, 7 is a microprocessor, and key switches 8. It has an input control function that reads the output of the detection circuit 4, an A/D conversion function that reads the body temperature and converts it A/D, and has an arithmetic function that processes these signals, an oscillation circuit 3, a relay 11. It has an output control function that sends control signals to circuit elements connected to the output terminal side, such as the indicator light 12 and the buzzer 13. 10 is a clock oscillation circuit. The key switch 8 is a group of switches for commanding temperature setting or starting, and the indicator lights 12. The buzzer 13 has a display function to indicate the energization state of the main body. A heater 6 is connected to the relay 11 and controls the heating of the heater 6.

FIG. 3 shows the configuration of the oscillation circuit 3 and the detection circuit 4 in FIG. 1.

In the figure, 14 is an inverter, resistor 15 and signal line 2
An oscillator is constructed by the capacitance C at RC
The frequency determined by is applied to a series resonant circuit consisting of a coil 16 and a capacitor 17 via an inverter 14, and then converted to DC by a diode 18. Reference numeral 19 indicates a comparator, and 20 indicates its reference potential section. Further, Ve and Vs indicate a reference potential and an input signal potential, respectively. The output Ns of the comparator 19 is the number of times Vs has fallen below Vc, and the number N's is input to the control circuit 5.

FIG. 4 shows how the signal lines attached to the main body in FIG. 1 are wired.

In the figure, 21 is an electrode line A, 22 is an electrode line B, and these electrode lines 21 and 22 form a pair to form one signal line 2. Reference numeral 23 indicates a part of the controller including the control circuit 5 and the like. Electrode wires A21 and B22
form parallel lines and are arranged in a mesh pattern in the main body 1, each having one end as the controller portion 23 and the other end as an open end.

FIG. 5 shows a sectional view of the main body 1. The main body 1 consists of a lining 25 and an outer material 24, and the electrode wires A21 and B22 are held between the lining 25 and the outer material 24 and fixed to the main body 1, similarly to the heater 1X26. In addition, the electrode wires A21 and 1322 avoid the area where the heater wires 26 are arranged, and
6, and are arranged in a mesh pattern on the main body 1 as described above. 27 indicates a decorative cover.

FIG. 6 shows an example of the person detection characteristics using the main body equipped with the person detection means configured as shown in FIGS. 4 and 5 and the detection circuit shown in FIG. 2. There is no person on the main body 1. If the solid line is
When there is a person present, the broken line indicates the change in the input signal Vs with respect to the frequency f in each case. When the capacitance C' of the signal line 2 when there is no one on the main body 1 is, for example, C': 300 pF, the oscillation frequency f' of the oscillation circuit 3 is f' when the resistor 15 is 2.7Ω. =
It becomes 250KHz. Frequency f when this person is not present
The coil 16 and the capacitor 17 are fixed so as to resonate with ', and the voltage peak value that resonates at that time is defined as Vs'. In such a state, if there is a person on the main body 1, the capacitance C" due to the signal line 2 will be C#= due to the capacitive component of the human body.
As a result, the oscillation frequency f1 increases to 4009F.
' = 200KHz. Therefore, the LC resonance voltage at the coil I6 and the capacitor 17 deviates from the above-mentioned resonance frequency, so that the voltage peak value Vs'
This results in a relationship of Vs'>Vs', which causes a difference in the input signal Vs to the comparator 19 when there is no person on the main body 1, and the reference potential Vc causes a difference in human detection as described above. Output N5te can be obtained and it can be determined whether there is a person present or not.

Effect of the invention According to the present invention, the following effects are achieved.

Since a pair of electrode wires is used as a means of detecting the presence or absence of a person, a detection means in which the capacitance between the electrode wires is more dominant than the capacitance between the electrode wires and ground can be realized, and the high-frequency current of the oscillation circuit can be Since the current is circulated between the electrode wires as a load, it responds sensitively to the presence or absence of a person, making it possible to use a highly reliable means of detecting people with reliable operation, as well as providing excellent heating comfort and power saving effects. A heating element control device for an electric heating appliance can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an outline of a heating element control device for an electric heating appliance according to an embodiment of the present invention. FIG. 2 shows a schematic control circuit diagram according to an embodiment of the present invention, and FIG. 3 shows a detection circuit diagram thereof according to an embodiment of the present invention. FIG. 4 is a perspective view of the main body showing the manner in which signal lines are attached according to an embodiment of the present invention, FIG. 5 is a sectional view of a main part of the main body according to an embodiment of the present invention, and FIG. FIG. 3 is a diagram showing human detection characteristics of a heating element control device for an electric heating appliance according to an embodiment. 1... Main body, 3... Oscillation circuit, 6...
Heater 21.22... Electrode wire.

Claims (5)

[Claims] (1) In a heating element control device for an electric heating appliance that performs heating control of a heater, the main body (1) is equipped with a heater (6).
) is attached with a pair of electrode wires (21) and (22), an oscillation circuit (3) is constructed in which the load is between the electrode wires (21) and (22), and the main body of the oscillation circuit (3) is (1) Heat generation of an electric heating appliance characterized by being equipped with a person detection means that controls the heating of the heater (6) by detecting a change in frequency due to a change in capacitance caused by a difference in whether or not a person is present in the heater (6). Body control device. (2) A pair of electrode wires (21), (22) are attached to the main body (1) equipped with a heater (6), and the electrode wires (22), (
22) Configure an oscillation circuit (3) with a load between
2. The heating element control device for an electric heating appliance according to claim 1, further comprising a person detection means for controlling the heating of the heater by detecting the magnitude of the DC level by DC conversion after being added to the resonance circuit. (3) A pair of electrode wires (21), (22) are attached to the main body (1) equipped with a heater (6), and the electrode wires (21), (
An oscillation circuit (3) is configured with the load between the heaters (22) and 22). 6) Heating element control for an electric heating appliance according to claim 1, wherein the electrode wires (21) and (22) are provided with a person detection means in which parallel lines or comb-shaped lines are arranged in a mesh pattern. Device. (4) A pair of electrode wires (21), (22) are attached to the main body (1) equipped with a heater (6), and the electrode wires (21), (
An oscillation circuit (3) is configured with the load between the heaters (22) and 22). 6) In addition to performing the heating control, the electrode wires (21) and (22) are provided with a person detection means sandwiched between the outer surface and the lining of the main body (1) which sandwich the heater (6). Heating element control device for electric heating equipment. (5) A pair of electrode wires (21), (22) are attached to the main body (1) equipped with a heater (6), and the electrode wires (21), (
An oscillation circuit (3) is configured with the load between the heaters (22) and 22). 6), and the electrode wires (21) and (22) are provided at the part of the main body (1) that holds the heater (6), and arranged to avoid the part of the heater (6). The heating element control device for an electric heating appliance according to claim 1, further comprising a person detection means.