JPS6352293B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a yagura kotatsu in which the power supply to a heating element provided on the yagura kotatsu main body can be wirelessly controlled by an operation unit provided on a table board.

<Prior art> Conventional Yagura kotatsu, for example, a Yagura kotatsu in which a control circuit that controls the energization of a heating element provided in the main body of the Yagura kotatsu is operated by an operation part provided on a table board, has an operation part on the table board and the above-mentioned Yagura kotatsu. It is constructed by connecting the control circuit of the Gurakotatsu body with a lead wire (cord), so when using the kotatsu futon on the Yagura Kotatsu body, the lead wires get in the way and the table board cannot be used freely. There was a drawback that it could not be placed in the correct direction.

<Objective> The object of the present invention is to provide a yagura kotatsu that eliminates the above-mentioned drawbacks.

<Example> An example of the tower kotatsu of the present invention will be described below with reference to the drawings.

The Yagura Kotatsu of the present invention is constructed as shown in the drawings, and in FIG.
), and the oscillation frequency changes depending on the voltage of the capacitor 13. The oscillation output of the VCO 1 is generated between an electrode plate 11A provided on the yagura kotatsu main body 11 and an electrode plate 12A provided on the table board 12 placed on the yagura kotatsu main body 11 so as to face the electrode plate 11A. Capacitance generated in (stray capacitance)
It is applied to the variable resonant circuit 10 provided on the table plate 12 through wireless connection via capacitor coupling by _CA. The variable resonance circuit 10 is formed of a capacitor, a coil, etc., and the resonance frequency is varied by adjusting the capacitance of the capacitor, the inductance of the coil, etc. using an operating section provided on the table plate 12. The resonance signal of the variable resonance circuit 10 is generated by the capacitance (stray capacitance) C generated between the electrode plate 12B provided on the table board 12 and the electrode plate 11B provided on the tower kotatsu main body 11 facing the electrode plate 12B. _B connects wirelessly through capacitor coupling and is applied to the detector 2 provided in the tower kotatsu main body 11.
An amplifier circuit 3 for amplifying the output signal of the detector 2 is connected to the detector 2 . The amplifier circuit 3
A detection circuit 4 for detecting the output signal of the amplifier circuit 3 (cutting out high frequencies) is connected to. The output signal of the detection circuit 4 has a resonance frequency as shown in FIG. 2A.
At _fp , the phase difference with the oscillation frequency signal of VCO1 disappears. Then, the detection circuit 4 includes the detection circuit 4.
When the phase of the output power signal and the oscillation frequency of the VCO 1 match, it is determined that the variable resonance circuit 10 is resonating at the resonant frequency, and the output becomes low level (earth potential), and otherwise becomes high level (power supply potential). ) is connected to the phase difference detection circuit 5. A resistor 14 and a capacitor 13 are connected to the phase difference detection circuit 5. A limiter circuit 6 is connected to the connection point between the resistor 14 and the capacitor 13, and when the potential of the capacitor 13 rises and the frequency of the VCO 1 becomes higher than the variable range of the variable resonance circuit 10, the output of the limiter circuit 6 becomes The impedance becomes low and the electric charge of the capacitor 13 is discharged, and the above
When the frequency of the VCO 1 becomes a voltage lower than the variable range of the variable resonant circuit 10, the output of the limiter circuit 6 becomes high impedance, and the capacitor 13
is charged via the resistor 14 by the position difference detection circuit 5. The capacitor 1 is connected to the capacitor 13.
3 is used as a reference voltage for temperature control, the reference voltage is compared with the output voltage of the temperature detection section (not shown) of the temperature detection circuit 7, and the detected temperature inside the Yagura Kotatsu is changed based on the comparison result. A temperature detection circuit 7 is connected. A power control circuit 8 is connected to the temperature detection circuit 7 and controls energization of the heating element 9 according to the output of the temperature detection circuit 7 to maintain the temperature at a predetermined temperature.

In addition, in FIG. 2, FIG. 2A is a frequency characteristic diagram of the phase difference between the output of the detection circuit 4 in FIG. 1 and the VCO 1, FIG. 2B is a voltage waveform diagram of the capacitor 13 in FIG. FIG. C is an output waveform diagram of the phase difference detection circuit 5 of FIG. 1.

Next, the operating state of the tower kotatsu of the present invention constructed as described above will be explained.

First, the resonant frequency f _p of the variable resonant circuit 10 of the table board 12 is set, and when the oscillation frequency of the VCO 1 is lower than the resonant frequency f _p , there is a phase difference between the output of the VCO 1 and the output of the detection circuit 4. The output of the phase difference detection circuit 5 becomes high level, the capacitor 13 is charged through the resistor 14, and the frequency of the VCO 1 rises to reach the resonant frequency f _p , so that there is no phase difference between the output of the detection circuit 4 and the output of the VCO 1. Therefore, the output of the phase difference detection circuit 5 becomes a low level, and the capacitor 13 is discharged via the low resistor 14. When the capacitor 1 is discharged, the voltage of the capacitor 13 decreases, so the frequency of the VCO 1 decreases,
When the frequency is away from the resonance frequency f _p , a phase difference occurs between the output of the detection circuit 4 and the output of the VCO 1, and the output power of the phase difference detection circuit 5 becomes high level, charging the capacitor 13 via the resistor 14. Then, the voltage of the capacitor 13 is increased, and the same operation is repeated.

Since feedback is applied to the VCO 1 as described above, the voltage of the capacitor 13 becomes a constant voltage proportional to the resonant frequency, and this voltage is used as a reference voltage for temperature control, and the temperature of the temperature detection circuit 7 is The temperature detection circuit 7 outputs an output when the output of the detection unit (not shown) is higher than the reference voltage, and the power control circuit 8 controls the power supply to the heating element 9 based on this output. The temperature inside the Yagura Kotatsu is maintained at a constant level. Variable resonant circuit 1 above
When the resonance frequency is varied at 0, the above capacitor 13
The constant voltage changes, the reference voltage for temperature control changes, and the output ratio of the temperature detection circuit 7 changes, so the energization rate to the heating element 9 controlled by the power control circuit 8 also changes. The temperature inside the chamber is controlled to a temperature corresponding to the resonance frequency varied by the variable resonance circuit 10.

In the above, the voltage of the capacitor 13 is used as the reference voltage for temperature control, and when the voltage becomes higher than this reference voltage, the temperature detection circuit 10 outputs an output, but when the voltage becomes lower than the reference voltage, the temperature The detection circuit 10 may be controlled to output.

<Effects of the Invention> Since the Yagura Kotatsu of the present invention has the above-described configuration, when the Yagura Kotatsu body is used with a kotatsu futon placed on it, the lead wires do not get in the way and the table board can be moved in any direction. Since only the variable resonant circuit that can be mounted and operated by the operation unit is provided on the table board, the space on the table board for the variable resonant circuit is used for the variable resistor, monostable multivibrator, and their power supply. It is extremely small compared to that provided in the temperature control signal generating means formed from a battery or the like. Therefore, there is no need to secure a special space for providing the variable resonant circuit, and the variable resonant circuit operated by the operating section can be easily provided at a desired position on the table board. Furthermore, since a battery serving as a power source can be eliminated, maintenance and inspection of the battery can be made unnecessary. Since the variable resonant circuit of the table board and the control circuit of the main body of the kotatsu are connected wirelessly by capacitor coupling, the temperature control signal generated by the temperature control signal generating means of the table board of the electric kotatsu is transmitted to the coil and iron core. Compared to the signal transmitted via a medium to the temperature control signal detection means provided on the electric kotatsu frame base, the Yagura kotatsu is subject to noise generated when controlling the temperature of surrounding equipment such as heating equipment such as electric carpets. This makes it possible to more reliably control the control circuit of the Yagura Kotatsu body using the operating section on the table board. Moreover, the space on the table plate for providing the electrode plate for capacitor coupling is small, and the electrode plate can be easily provided at a desired position on the table plate.

Moreover, since the resonance state is detected by the phase difference between the output voltage signal of the detection circuit and the voltage signal of the oscillation frequency of the voltage controlled oscillation circuit, even if the distance between the table board and the main body of the Yagura Kotatsu is large, external noise will prevent The phases of the voltage signals of the detection circuit and the voltage control oscillation circuit are not affected, so malfunctions due to external noise can be prevented, and accurate temperature control can be performed.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the tower kotatsu of the present invention, Fig. 2A is a frequency characteristic diagram of the phase difference between the output of the detection circuit shown in Fig. 1 and the VCO, and Fig. 2B
is a voltage waveform diagram of the capacitor in FIG. 1, and FIG. 2C is an output waveform diagram of the phase difference detection circuit in FIG. 1. In the drawing, 9 is a heating element, 10 is a variable resonant circuit, 1
1 indicates the main body of the Yagura Kotatsu, and 12 indicates the table board.

Claims (1)

[Claims] 1. A variable resonant circuit whose resonant frequency changes according to the operation of the operating section is provided on the table board, a voltage controlled oscillation circuit whose oscillation frequency changes according to changes in applied voltage, and an oscillation frequency of the voltage controlled oscillator circuit. a detection circuit that detects the voltage via the variable resonant circuit, a detection means that detects that the output voltage signal of the detection circuit matches the phase of the voltage signal of the oscillation frequency of the voltage controlled oscillation circuit, and the detection means voltage applying means for adjusting the voltage applied to the voltage controlled oscillation circuit so as to change the voltage signal at the oscillation frequency of the voltage controlled oscillation circuit in a direction that matches the voltage signal at the resonant frequency of the variable resonance circuit by the output of the voltage controlled oscillation circuit; , a control circuit consisting of a power control means for controlling energization to the heating element in accordance with the voltage of the voltage applying means is provided on the Yagura Kotatsu body; electrode plates are provided on the table board and the Yagura Kotatsu body respectively; A tower kotatsu characterized in that the control circuit and the variable resonance circuit are coupled by a capacitor.