JPS6342163B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a Yagura Kotatsu in which the power supply to a heating element provided in the Yagura Kotatsu body can be wirelessly controlled by an operation unit provided on a table board, and particularly to a Yagura Kotatsu that is installed between the table board and the Yagura Kotatsu body. The present invention relates to a kotatsu (Japanese kotatsu) in which the energization of a heating element can be reliably controlled even if the thickness of the kotatsu futon used is different.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the Yagura Kotatsu of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a voltage controlled oscillation circuit (hereinafter referred to as VCO) provided in the main body 15 of the kotatsu, and its oscillation frequency changes depending on the output voltage of the waveform shaping circuit 8. The oscillation output of the VCO 1 is generated by the electrode plate 12A provided on the Yagura Kotatsu body 15 and the electrode plate 12.
An electrode plate 1 provided on a table plate 16 placed on the Yagura Kotatsu main body 15 and used so as to face A.
3A, the capacitance (stray capacitance) C ₁ causes a wireless connection through capacitor coupling and is applied to the variable resonant circuit 14 provided on the table board 16 . The variable resonance circuit 14 is formed of a capacitor, a coil, etc., and the capacitance of the capacitor or the inductance of the coil is determined by the table plate 16.
The resonant frequency can be varied by operating an operating section provided in the resonant frequency. The resonance signal of the variable resonance circuit 14 is transmitted through the electrode plate 13B provided on the table plate 16 and the electrode plate 13B.
Capacitance (stray capacitance) generated between the electrode plate 12B provided on the Yagura Kotatsu body 15 so as to face
The signal is applied to the detector 2 provided in the Yagura Kotatsu body 15 through wireless connection via capacitor coupling via C ₂ . The detector 2 is connected to an AGC amplifier (automatic gain control amplifier) 3 that amplifies the output signal of the detector 2 to a constant amplitude. Applicable
A mixer (mixing circuit) 4 that mixes the output signal of the AGC amplifier 3 and the oscillation output of the VCO 1 is connected to the AGC amplifier 3. A comparison circuit 5 is connected to the mixer 4, which outputs an output signal if the output signal of the mixer 4 is equal to or higher than a predetermined value _VD . When the output signal of the comparison circuit 5 is not input to the comparison circuit 5, the square wave oscillation circuit 6 and the integration circuit 7
The comparison circuit 5 outputs a sawtooth wave formed by
When the output signal is inputted, a waveform shaping circuit 8 is connected which outputs a DC signal that keeps the output voltage constant at that time. The waveform shaping circuit 8 has the above-mentioned
A VCO 1 is connected, and a DC signal from the waveform shaping circuit 8 is applied. In addition, the waveform shaping circuit 8
A temperature detection circuit 9 is connected to the temperature detection circuit 9, and the output of the waveform shaping circuit 8 is applied as a reference voltage to the temperature detection circuit 9 inside the kotatsu main body 15. The temperature detection circuit 9 is connected to the heating element (heater) 1 of the kotatsu main body 15 based on the output signal of the temperature detection circuit 9.
A power control circuit 10 that controls energization of 1 is connected.

In the above configuration, the variable resonance circuit 14 changes the resonance frequency to the VCO1 by operating the operation section.
The oscillation frequency can be changed within the range of the oscillation frequency, and a signal whose position changes depending on the resonance state is output.

Next, the operating state of the Yagura Kotatsu constructed as described above will be explained.

First, when the operating section provided on the table board 16 is operated to set the resonant frequency f ₀ of the variable resonant circuit 14, the oscillation frequency f of the VCO 1 and the variable resonant circuit 1 are set.
4 resonant frequency f ₀ is separated and becomes a non-resonant state, as shown in Figure 2c, the phase difference between the signal V ₁ of VCO 1 and the signal V ₂ detected by detector 2 and amplified by AGC amplifier 3. The signal that came is mixer 4
When the signals are mixed, the output becomes a signal such as V ₃ which is lower than the reference voltage V _D of the comparator circuit 5, and no signal is output from the output of the comparator circuit 4. Therefore, the waveform shaping circuit 8 outputs a sawtooth wave formed by the square wave oscillation circuit 6 and the integrating circuit 7 as shown in FIG. 2a.

The oscillation frequency of the VCO 1 sweeps from f ₁ to _{f 2} in response to its output as shown in FIG. Become. When the state is in tune, the detector 2 receives a signal that has no phase difference with the oscillation signal of VCO 1 (shown as V ₁ in Figure 2 d).
is input. When that signal is amplified by AGC amplifier 3 and input to mixer 4, the mixed output is the signal of AGC amplifier 3 and VCO 1 because it is in phase with the oscillation signal of VCO 1 (shown as V ₂ in Figure 2 d).
(shown as V ₃ in Figure 2d).
Since the signal is higher than the reference voltage of the comparator circuit 5, the signal is output and the output of the waveform shaping circuit 8 becomes constant at the potential at which the resonance state is achieved, and the oscillation frequency of the VCO 1 also becomes constant at the resonance frequency _f0 .

In addition, the temperature detection circuit 9 receives the above-mentioned constant level potential as a reference voltage, and therefore the power control circuit 9 maintains the output at a temperature corresponding to the reference voltage.
By controlling 0, the power of the heating element 11 is adjusted to keep the temperature inside the kotatsu body 15 constant. The set temperature can be varied by changing the resonant frequency of the variable resonant circuit 14 by operating the operating section, whereby a voltage corresponding to the resonant frequency _f0 is input to the temperature detection circuit 9, and the temperature corresponding to that voltage becomes the set temperature. can be varied.

When the thickness of the kotatsu futon increases in the Yagura Kotatsu with the above configuration, the capacitance C ₁ generated between the electrode plates 12A and 13A and the capacitance C ₂ generated between the electrode plates 12B and 13B become smaller, so the impedance increases. , even if the level of the signal from the variable resonance circuit 14 detected by the detector 2 becomes low.
Since the same level of signal can be input to the mixer 4 by the AGC amplifier 3, it is not affected by the thickness of the kotatsu futon, etc.

However, in the past, since an amplifier with a constant gain was used instead of the AGC amplifier 3 of the present invention, the thickness of the kotatsu futon increased and the capacitance C ₁ and capacitance generated between the electrodes 12A and 13A and between the electrodes 12B and 13B were increased.
When the impedance of C ₂ increases, detector 2
The level of the signal detected by the mixer 4 becomes low, and the low level signal is amplified by the amplifier and input to the mixer 4. However, the mixer 4 mixes the oscillation signal and the output of the amplifier and outputs a signal that is the sum of the amplitudes of both signals in the same phase, but the signal from the amplifier is
As shown by V ₂ , the output of the mixer 4 (indicated by V ₃ in FIG. 2 e) becomes lower than the reference voltage V _D of the comparator circuit 5 even when the phase is the same, and the signal is not output from the comparator circuit 5. As a result, the tuning frequency f ₀ of the variable resonance circuit 14 cannot be detected.

In the Yagura Kotatsu of the present invention, only the variable resonant circuit operated by the operating part is provided on the table board as described above, so the space for installing the variable resonant circuit operated by the operating part on the table board is It is extremely small compared to multivibrators and those equipped with temperature control signal generation means formed from batteries, etc., which serve as their power source, and a special space is secured for installing a variable resonant circuit as the operation part of the table board. The variable resonant circuit operated by the operation unit can be easily installed at the desired position on the table board, and the battery that serves as the power source for the table board can be eliminated, so there is no need for battery maintenance and inspection. Moreover, since the control circuit of the Yagura Kotatsu body and the variable resonance circuit of the table board are connected wirelessly by capacitor coupling through the electrode board, the temperature control generated by the temperature control signal generating means of the table of the electric Gotatsu can be controlled. Compared to the one in which the signal is transmitted to the temperature control signal detection means provided on the frame of the electric kotatsu via a medium consisting of a coil and iron core, the temperature control of surrounding equipment that uses the Yagura Kotatsu, such as electric carpet heating equipment, is more effective. The control circuit of the Yagura Kotatsu body can be controlled by a variable resonance circuit that is operated more reliably by the operation part on the table board, and is less affected by the noise generated during the operation.Moreover, the space required for the electrode plate is small. It can be easily installed at the desired position on the table board, and the AGC amplifier in the control circuit allows the heating element to be energized even if the thickness of the kotatsu futon interposed between the table board and the Yagura Kotatsu body is different. It can be controlled reliably.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the kotatsu of the present invention, and FIGS. 2a to 2e are voltage waveform diagrams during operation to explain the operation of FIG. 1. In the drawings, 3 is an AGC amplifier, 10 is a power control circuit, 11 is a heating element, 14 is a variable resonance circuit, 15 is a kotatsu body, and 16 is a table board.

Claims (1)

[Claims] 1 Only a variable resonant circuit that is operated by the operation part is provided on the table board, and a heating element is placed on the main body of the Yagura Kotatsu on which the table board is placed and the resonant frequency of the variable resonant circuit is detected when electricity is applied to the heating element. death
A control circuit is provided to keep the output of the variable resonant circuit constant using an AGC amplifier, and an electrode plate is connected to the table to connect the main body of the kotatsu and the variable resonant circuit of the table plate wirelessly through capacitor coupling. Yagura kotatsu is characterized by the fact that each board has its own structure.