JPH0241875B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a large-area electric heater, such as a hot carpet, and in particular to one that senses the presence of a person and automatically energizes the heater wire.

Electric heaters that cover a relatively large area, such as hot carpet heaters, have a large calorific value of about 600W to 800W, so they have the disadvantage of higher electricity costs. For this reason, a power switch is provided in the temperature controller section or a part of the carpet body, and the user turns the power switch on each time the carpet is used and turns it off when not in use to reduce wasteful power consumption. However, it is extremely troublesome to turn on and off the aforementioned power switch each time the user uses or does not use it, and if this operation is forgotten or mistakenly done, the heater wires may be disconnected even when no one is present. It was energized and heated up, resulting in not only wasted power consumption, but also a dangerous situation. Furthermore, a phenomenon occurred in which heating was not achieved if the power switch was not turned to the ON side even though heating was required. In addition, in order to eliminate the above-mentioned drawbacks, a pair of upper and lower electrode plates with an insulator interposed therein having appropriate notches at predetermined locations is provided in the carpet body, and the weight of the human body allows the electrode plates to be connected to each other through the notches. There is a device that energizes the heater wire by mechanically contacting the electrode plates, but in this case, it is a weight detection method, so if another heavy object (e.g. a low table, furniture, etc.) is placed on it. It also generated heat, causing unnecessary heating and a loss of power consumption.

Furthermore, integral conductive electrodes are provided in the carpet body to face each other, and the capacitance change between the electrodes, i.e.,
Some carpets detect an increase in stray capacitance caused by a person standing on the carpet body and energize the heater via a control circuit.

However, the stray capacitance between a pair of adjacent conductive electrodes varies greatly depending on the humidity within the carpet itself, the properties of the materials of each component, and the humidity and inductive capacitance of the floor surface on which it is laid. It was difficult to initialize the specific capacitance under normal conditions, and the heater was not energized even when there was a person on it.

The present invention improves the above points and will be explained below based on the drawings.

The drawings show an embodiment on a hot carpet, and FIG. 1 shows a wiring pattern. Reference numeral 1 denotes a rectangular heater body with a relatively wide area, which is divided by a dividing part 2 into a plurality of heating blocks 3A and 3B (two sides). Reference numerals 4A and 4B denote capacitance detectors disposed in each of the heating blocks, which are constructed from the following members. That is, a pair of conductive electrodes 5a, 5b, 5a, 5b made of metal foils of different polarities made of copper are arranged close to each other in a comb shape on a plane with a predetermined interval, and a polyester film is placed on the upper and lower surfaces of the electrodes. Insulating sheets 6, 6 are attached. One of the electrodes is common to each heating block side. Furthermore, as shown in FIG. 1, at least one of the conductive electrodes has a portion A located on the dividing portion 2 side of each heating block 3A, 3B having a larger planar area than the other portion B. 7 is a cushion material such as foamed urethane provided below the sheet, 8 is a foil-like planar electrode made of aluminum foil, and insulating sheets 9 made of polyester film are pasted on both upper and lower surfaces of the electrode. This adhesive body is provided below the cushion material 7. The capacitance detection body is constituted by the above-mentioned members. 10A and 10B are the capacitive detectors 4
The heating block 3A, which is located below A and 4B,
Linear heaters arranged in a meandering manner in each of 3B,
Reference numeral 11 denotes a heat insulating material such as felt, and 12A and 12B are located below the capacitance detectors 4A and 4B, similar to the heaters, and arranged in a meandering manner close to the heaters 10A and 10B in the heating blocks 3A and 3B, respectively. The installed linear detection wire detects the temperature of the body of the warming device and controls the heaters 10A and 10B to maintain the temperature at the set temperature. 13 is the capacitive detector 4A,
4B is a relatively thin cushion material such as foamed urethane provided on the upper surface; 14 is a surface covering such as nylon taffeta;
15 is a terminal connector provided at one corner of the heater main body 1, and 16 is a remote controller provided with a connecting connector 17 on one side.

Figure 4 shows a schematic electrical circuit diagram.
Reference numeral 1 denotes a reference oscillation circuit, which has a thermistor (TH) with positive or negative characteristics for adjusting its output pulse. This thermistor is disposed in the terminal connector 15 near the heaters 10A, 10B, and compensates for changes in the characteristics of the capacitance detectors 4A, 4B due to temperature. RC is an inverting shaping circuit which uses the output pulse of the reference oscillation circuit OS-1 as an inverting input and inverts the output pulse and inputs it to the gate of a variable oscillation circuit which will be described later.OS-2 has one gate that receives the output of the inverting shaping circuit RC. The other gate serving as an input is a variable oscillation circuit serving as an input for detecting a capacitance change of the capacitance detector 4A, and changes the number of pulses within the output pulse period of the inverting shaping circuit RC according to the capacitance change. CNT is the reference oscillation circuit
A counter circuit that is set to a set state by the output of OS-1, counts the output pulses of the variable oscillator OS-2, and after a predetermined number of counts, generates an off-pulse from the 1 output pin, F, F uses this off-pulse as input and further inverts the The reference oscillator OS by applying the clear input of the shaping circuit RC
A flip-flop circuit synchronizes with the output of -1, I and L are differential and integral circuits, TR is a transistor that integrates the output of the flip-flops F and F and uses it as a base current, and PC is a transistor that causes the light emitting element LP on one side to emit light. The optical coupler RY that makes the optically coupled light-receiving element LS on the other side conductive is a relay connected to the coupling part, and turns on the relay contact RYS connected in series to the heater 10A.

As many circuits as described above are provided as there are heating blocks.

Next, the operation will be explained with reference to each drawing including FIG. 5. When there is no load on the heater body 1, as shown in Fig. 5A, the adjacent conductive electrodes 5a and 5b
A stray capacitance C1 is formed between them, and stray capacitances C2, C2 are formed between the conductive electrode and the planar electrode 8. When a person is placed on one of the heating blocks 3A of the heater body 1 as shown in FIG. , C3, and the stray capacitance increases.
As the capacitance increases, the output pulse of the variable oscillator OS-2 decreases, and one output of the counter circuit CNT does not generate an off pulse, but the on pulse turns on the transistor TR, causes the light emitting element LP to emit light, and turns on the light receiving element LS. Then, relay RY is driven, relay contact RYS is turned on, and the heater 10A on the heating block 3A side on which person M is placed is energized to generate heat. The intervening electrode 8 is connected to the ground side of an electric circuit independent of the heater 10A side via stray capacitances C2 and C2, thereby suppressing the influence of capacitance induced from the power supply side and also connecting each heating block 3.
It has the same potential as the ground side of A and 3B to prevent interference between the heating blocks. In particular, since the capacitance detectors 4A, 4B and the planar electrode 8 are provided on the entire upper and lower surfaces of the cushion material 7, the respective conductive electrodes 5a, 5
b, 5a, and 5b have the same conditions no matter which part you look at, and the specific capacitance is stable. That is, the capacitance changes due to the moisture inside the heater body, the properties of each component (insulating sheet, cover, cushion body), moisture on the floor, etc. can be measured by detecting the capacitance on the upper and lower surfaces of the cushion material 7 with the capacitance detector 4A,
Since it is covered by 4B and the planar electrode 8, the return shape of the cushion material 7 after a person is placed on it and leaves the main body is accurate due to the capacitive detector, 4A, 4B and the planar electrode 8. Therefore, the shape of the cushion material 7 is always regular and falls within the standard at the time of initial setting of the variable oscillator OS-2. Moreover, the planar electrode 8
may be in the form of a fine mesh rather than in the form of a foil, but it is necessary to provide it over the entire lower surface of the capacitive detector.

As described above, the present invention provides a capacitance sensor configured by pasting insulating sheets on both the upper and lower surfaces of a pair of conductive electrodes made of metal foils of different polarities, which are arranged close to each other in a planar comb shape with a predetermined interval. A cushion body provided below the detection body, a planar electrode provided on the entire surface below the cushion body, and a heater provided below the cushion body, and a capacitance change between the conductive electrodes is detected. Since the heater is controlled by the heater, a capacitive detector and a planar electrode are provided on the upper and lower surfaces of the cushion material, so that the restoring action of the capacitive detector and the planar electrode prevents a person from leaving the main body. The subsequent return shape of the cushion material becomes accurate, and the specific capacity becomes stable when there is no load (no person is on it). This allows for accurate initial settings. Therefore, during use, malfunctions such as the heater generating heat even when there is no person on it, or conversely the heater not generating heat even when there is a person on it, are eliminated, and it also eliminates malfunctions caused by humidity in the outside air or individual differences. It will work reliably even if there are differences in capacity.

[Brief explanation of drawings]

Fig. 1 is a wiring pattern diagram of the conductive electrode of the wide-area electric heater of the present invention, Fig. 2 is a side sectional view of the same, Fig. 3 is a side sectional view of the main part, and Fig. 4 is an electric circuit diagram. Figures A and B are diagrams of the basic principle. 1... Heater body, 4A, 4B... Capacity detection body, 5a, 5b, 5a, 5b... Conductive electrode, 8...
... Planar electrode, 10A, 10B... Heater.

Claims (1)

[Claims] 1. A capacitance detector constructed by pasting insulating sheets on both upper and lower surfaces of a pair of conductive electrodes made of metal foils of different polarities arranged closely in a planar comb shape with a predetermined interval, and the detector a cushion body provided below; a planar electrode provided on the entire surface below the cushion body;
What is claimed is: 1. A wide-area heating type electric heater, comprising: a heater provided below the electric heater; and the heater is controlled by detecting a change in capacitance between the conductive electrodes.