JP2556400B2 - Remote control amplifier and its control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for remotely controlling state changing means such as a variable attenuator included in an amplifier from a remote location, and more particularly to a device for controlling a plurality of state changing means. .

[0002]

2. Description of the Related Art Conventionally, as a device for remotely controlling an amplifier from a remote position as described above, when a television broadcast signal received by an antenna provided outdoors is amplified by an amplifier provided on a column or the like of the antenna. Some control the gain of this amplifier indoors at a distance. An example of such a device is shown in, for example, Japanese Utility Model Publication No. 58-52740. As shown in FIG. 9, the positive half wave of the AC voltage generated on the secondary side of the power transformer 2 is taken out by the diode 4 and the level thereof is adjusted by the variable resistor 6 to be the gain adjustment voltage. The high voltage blocking coil 12 and the transmission line 14 are combined with the operating voltage composed of the negative half-wave of the AC voltage extracted by the diode 8 at the connection point 10.
Is transmitted to the variable gain amplifier 16 side via the. Transmitted
The negative half-wave of the AC voltage is rectified and smoothed by the rectifying / smoothing circuit including the high-frequency blocking coil 18, the diode 20, and the capacitor 22, and the power source terminal 23 of the variable gain amplifier 16 is supplied.
Is supplied to. Meanwhile, the AC voltage whose level is adjusted
The positive half-wave of the
4, rectified and smoothed by the rectifying / smoothing circuit including the capacitor 26, and supplied to the gain control voltage input terminal 28. Therefore, the gain of the variable gain amplifier 16 is adjusted to the gain according to the value adjusted by the variable resistor 6.

[0003]

However, the above-mentioned device can only adjust the gain of one variable gain amplifier. As shown in Japanese Patent Publication No. 61-54292, even if the positive half-wave and the negative half-wave of the AC voltage are used as the gain adjusting voltages, only the gains of two amplifiers can be adjusted. Can not. The television broadcast signal has a UHF band and a VHF band, and moreover, V
The HF band is divided into a low channel and a high channel. Therefore, when amplifiers are provided in these three bands and the gains of these three bands are to be controlled from remote locations, the above-mentioned device cannot be implemented. In addition, when controlling the gains of a plurality of amplifiers all to be the same, the above device can be used, but in the case of an amplifier for amplifying different bands as described above, it is necessary for each amplifier. Since the gains to be obtained are often different from each other, they cannot be practically used in the above-mentioned device. Further, in the device as described above,
It is premised that AC power is supplied to the variable gain amplifier, and there is a problem that it cannot be used when DC power is supplied.

According to the present invention, the signal states of a plurality of, especially three or more state changing means can be controlled individually from distant positions, and the amplifier having the state changing means has a DC power source and an AC power source. It is an object of the present invention to provide a remote control amplifier and its control device which can be used regardless of the type of power supply.

[0005]

In order to achieve the above object, the remote control amplifier of the present invention has a plurality of state changing means for changing the state of the signal according to the level of the state adjusting signal, as the amplifying means. It is provided. The amplifying means is provided with an extracting means for extracting the modulation control signal from the superimposition signal obtained by superimposing the modulation control signal and the operation power supply output to the amplification means. The modulation control signal has the same number as that of the state varying means and has a frequency different from the output signal of the amplifying means and the output of the operating power supply.
Amplification is a composite signal of control signals , each of which is a number and has a different frequency, and whose levels are individually adjusted.
A carrier wave having a frequency different from the output signal of the means and the output of the operating power supply is modulated. Also, the remote control amplifier according to the present invention includes demodulation means for demodulating the extracted modulated control signal into the composite signal, and demultiplexing the demodulated composite signal into the control signals, and then converting the state control signal into the state adjustment signal. It also has demultiplexing conversion means for converting and supplying it to the corresponding state changing means. Further, the control device according to the present invention is provided at a position apart from the amplification means. An operating power supply output generating means for generating an operating power supply output to the amplifying means, an output signal of the amplifying means, and an operating power supply.
Frequency different from output and different from each other
The oscillating means for generating the same number of oscillating signals as the state varying means, the control signal generating means for individually adjusting the level of each oscillating signal to generate a control signal, and the combined signal of the control signals. , The output signal of the amplification means and the operating voltage
Modulation control signal generating means for modulating a carrier wave of a frequency different from the source output to generate a modulation control signal, and superimposing means for superimposing the modulation control signal on the operating power supply output so as to be transmitted to the amplifying means, It has.

[0006]

According to the present invention, the operation power supply output generating means
The operating power output is supplied to the amplifying means via the transmission line ,
The amplification means operates. In addition, the composite signal of each control signal
Modulation control signal that modulates the transmission wave is amplified via the transmission line
It is supplied to the means side. Each modulation control signal is demodulated by the demodulation means into a combined control signal. This composite control signal is
The signals are demultiplexed by the demultiplexing conversion means, converted into state adjustment signals, and supplied to the corresponding state changing means. Moreover, each
It is possible to individually adjust the signal status in the status change means.
In this case, the variable adjusting function of each amplifying means is performed. Each control signal is
At a frequency different from the output signal of the amplification means and the operating power output
And the frequencies are different from each other, and the carrier wave is also amplified
At a frequency different from the output signal of the means and the operating power output
It Therefore, the control signal or carrier wave is the output signal of the amplification means.
Each state can be changed without adversely affecting the operating power output
The means can be controlled individually. Moreover, the control signal is the level
Since it is adjusted, the state change means is controlled in detail.
it can.

[0007]

EXAMPLE A first example is shown in FIGS. In this embodiment, as shown in FIG. 1, a so-called booster 30 and
The power source and control device 32, and the booster 30
Is for amplifying a VHF band television broadcast signal and a UHF band television broadcast signal received by an antenna (not shown). The VHF band television broadcast signal input from the input terminal 34 is The wave 36 splits the low-channel television broadcast signal V _L and the high-channel television broadcast signal V _H. The low-channel television broadcast signal V _L is amplified by a low-channel amplifier 44 having a state changing means 42 between the front-stage amplifier 38 and the rear-stage amplifier 40. Similarly, the high-channel television broadcast signal V _H is transmitted to the pre-stage amplifier 46.
Is amplified by a high-channel amplifier 52 having a state changing means 50 between it and the latter-stage amplifier 48. Low-channel television broadcast signal V amplified in this way
_L and the high channel television broadcast signal V _H
It is mixed in the mixer 54. Further, the UHF band television broadcast signal input from the input terminal 56 receives the band pass filter 58, the pre-stage amplification section 60, the state changing means 62,
It is amplified by the UHF amplifier 68 including the middle stage amplifying unit 64 and the second stage amplifying unit 66. The amplified television broadcast signal in the UHF band is mixed by the mixer 70 with the television broadcast signal in the VHF band from the mixer 54, and is output via the capacitor 72 of the superposition circuit 71 to the output terminal 7.
4 and is supplied to the power supply and control device 32 via a line, for example, a coaxial cable 76.

As the state changing means 42, 50, 62,
For example, a variable attenuator 78 as shown in FIG. 2 can be used. This variable attenuator 78 includes a PIN diode 8
0, the cathode side of which is grounded through a resistor 82, and the anode side of which is supplied with a DC voltage through a resistor 84, and the DC voltage is changed to change the PIN voltage.
By changing the high frequency resistance value of the diode 80, the attenuation amount of the high frequency signal flowing from the cathode side to the anode side of the PIN diode 80 is changed. Reference numeral 86 is a bypass capacitor, and a DC voltage for controlling the amount of attenuation is given from a demultiplexing converter 88 described later.

Returning again to FIG. 1, the UHF band and VHF band television broadcast signals supplied from the booster 30 to the power supply and control device 32 via the coaxial cable 76 are supplied from the terminal 90 to the superposition circuit 92. It is supplied to the terminal 96 via the capacitor 94 of the circuit 92. Since this terminal 96 is connected to, for example, a television receiver, the UHF band and VH amplified by the booster 30 are used.
An F band television broadcast signal is supplied to the television receiver.

The power supply and control device 32 has a transformer 98 for transforming a commercial AC voltage. The AC voltage induced on the secondary side of the transformer 98 is rectified by a rectifying circuit 100 and further with a capacitor 102. The smoothing circuit 106 including the high frequency choke 104 converts the voltage into a DC voltage, and the high frequency blocking coil 110, which is the primary coil of the mutual induction coupling circuit 108 of the superposition circuit 92, the terminal 90, and the coaxial cable 76.
Is supplied to the output terminal 74 of the booster 30 via.

The power supply and control device 32 has an oscillating section 112, and the oscillating sections 112 have oscillating frequencies of, for example, 4.75 KHz (f1), 38 KHz (f2), 3
Three oscillation circuits 1 having a frequency relationship of 8 times with 04 KHz (f3) and having the same number as the state changing means 42, 50, 62.
It has 14, 116 and 118. This oscillator circuit 11
4 is the three inverters 120, 1 as shown in FIG.
22 and 124, resistors 126 and 128, and capacitor 130, and the values of resistors 126 and 128 and capacitor 130 are selected so that the oscillation frequency is 4.75 KHz. This oscillation signal is output through the bandpass filter 132 in order to prevent generation of unnecessary harmonics. Since the oscillator circuits 116 and 118 have the same configuration, detailed description thereof will be omitted, but the difference is that the oscillation frequencies are 38 KHz and 304 KHz, respectively.

Oscillation signals of the oscillation circuits 112, 116 and 118 are supplied to the control unit 134 shown in FIG. The control section 134 has level variable circuits 136, 138, 140 connected to the oscillation circuits 114, 116, 118. These level variable circuits 136, 138, 140
As shown in FIG. 3, one end is grounded, and the other end is connected through the capacitors 142, 144, 146 to the oscillation circuits 114, 1
Variable resistor 148 connected to the output side of 16, 118,
It has 150 and 152. Therefore, when the sliders of the variable resistors 148, 150, 152 are slid, the levels of the oscillation signals generated between the sliders and the ground potential point are set to different values. A level controlled oscillation signal, or control signal, generated between each slider and the ground potential point causes each slider to have a resistor 154, 15
6, 158 and are connected to each other to be combined.

This combined control signal is applied to the modulator 1 shown in FIG.
60 modulation circuit 162. This modulation circuit 16
2 has an amplifier circuit 166 for amplifying the combined control signal as shown in FIG. 3, and this amplifier circuit 166 includes a transistor 164, the amplified output of which is supplied to the emitter of the amplitude modulation transistor 168. It Further, the modulation circuit 162 has a crystal oscillation circuit 170, and the oscillation circuit 170 includes a crystal oscillator 172 and an oscillation transistor 1
74, and a VHF band television broadcast signal and U
A frequency that does not affect the HF band television broadcast signal and is lower than the television broadcast signal (f0).
Oscillates the carrier wave and supplies the carrier wave to the base of the amplitude modulation transistor 168. Therefore, from the collector of the amplitude modulation transistor 168, a modulation control signal obtained by amplitude-modulating the carrier wave with the composite control signal is obtained. The state of this modulation control signal is shown in FIG. Since the carrier wave is amplitude-modulated by the control signal, it is f0 ± on both sides of the carrier wave (f0).
Sidebands f1, f0 ± f2, and f0 ± f3 are generated, and the degree of modulation of these sidebands changes according to the level of each control signal. This modulation control signal is applied to the capacitor 1
76 and the unbalanced attenuation circuit 180 via the band pass filter 178. Bandpass filter 178
Is for preventing unnecessary harmonic leakage.

The modulation control signal from the unbalanced attenuation circuit 180 is mutually inductively coupled with the high frequency blocking coil 110 on the primary side of the mutual inductive coupling circuit 108, and the resonance circuit 18 on the secondary side is provided.
1 is supplied. Therefore, the direct current voltage from the smoothing circuit 106 to which the modulation control signal is mutually induced is supplied to the terminal 90, and from there, is supplied to the output terminal 74 of the booster 30 via the coaxial cable 76. That is, booster 30
A signal obtained by superimposing a modulation control signal on a DC voltage is transmitted from the power supply and control device 32 through the coaxial cable 76. The unbalanced attenuator circuit 180 is for attenuating the level of the modulation control signal. The level of the unbalanced attenuator circuit 180 is attenuated by the modulation control signal to the high frequency blocking coil 110 on the primary side of the mutual induction coupling circuit. This is to balance with the DC output of the smoothing circuit 106 so as to mutually inductively couple, and to remove harmonics of the modulation control signal.

The superposed signal transmitted through the coaxial cable 76 is supplied to the demodulator 184 in the booster 30 via the high frequency blocking coil 182 of the superposing circuit 71. As shown in FIG. 5, the DC voltage of this superposed signal passes through the high frequency blocking coil 186 and the resistor 188 and the capacitor 190.
Is further smoothed by a smoothing circuit 192 composed of
The amplifiers 38, 40, 46, 48, 60, 6 shown in FIG.
4, 66 and the respective amplification / smoothing circuits 213, 214, 216 are supplied as operating DC voltage.

The modulation control signal of the superimposed signal is separated from the superimposed signal, that is, extracted by the capacitor 194 and the bandpass filter 196, and the diode 198,
Demodulator 204 including capacitor 200 and resistor 202
Is demodulated into a combined control signal. Then, the demodulated combined control signal is supplied to the demultiplexing converter 88.
The demultiplexing converter 88 includes a bandpass filter 206,
It has a demultiplexing circuit 212 composed of 208 and 210.
The bandpass filter 206 has a bandpass filter 20 in a narrow passband that allows a 4.75 KHz signal to pass therethrough.
8 to a narrow pass band for passing a signal of 38 KHz, vans
The de-pass filters 210 are each configured in a narrow pass band that passes a 304 KHz signal. Therefore,
4.75KH on the output side of the bandpass filter 206
control signal z is the output side of the band-pass filter 208 is a control signal of 38KHz is, band-pass filter 2
A control signal of 304 KHz is demultiplexed from the combined control signal and output to the output side of 10.

These respective control signals are supplied to the amplification / rectification / smoothing circuits 213, 214, and 216, respectively. The amplification / rectification / smoothing circuit 213 amplifies the control signal of 4.75 KHz by the amplification circuit 222 including the transistors 218 and 220. The operating voltage to the amplifier circuit 222 is
It is supplied from the smoothing circuit 192. Amplified 4.7
The 5 KHz control signal is rectified and smoothed by a rectifying and smoothing circuit 228 including a diode 224 and a capacitor 226,
It is supplied to the state changing means 42 as a DC voltage for controlling the amount of attenuation. Similarly, the control signal of 38 KHz is amplified, rectified and smoothed by the amplifying rectifying / smoothing circuit 214 and is supplied to the state changing means 50 as a DC voltage for controlling the amount of attenuation, and the control signal of 304 KHz is the amplifying rectifying / smoothing circuit. Amplified, rectified and smoothed by 216, and the state changing means 62
It is supplied as a DC voltage that controls the amount of attenuation.

Since the level of the 4.75 KHz oscillation signal is adjusted by the level variable circuit 136,
The amount of attenuation of the state changing means 42, and thus the gain of the VHF band low channel amplifier 44, is determined by the output of the level changing circuit 136 .
The level of the vibration signal is adjusted according to the level adjustment. Similarly, the amount of attenuation of the state changing means 50, and thus the gain of the VHF band high channel amplifier 52, is 38K in the level changing circuit 138.
The level of the oscillation signal of Hz is adjusted according to the level adjustment. Similarly, the attenuation amount of the state changing means 62, and thus the gain of the UHF amplifier 68 is 304 KHz in the level changing circuit 140.
In accordance with the level adjustment of the oscillation signal of. In this way, in this embodiment, even if three amplifiers are provided, the gain of each amplifier can be adjusted individually.

FIG. 6 shows a second embodiment. In the first embodiment, the carrier wave is amplitude-modulated by the composite control signal, but in the second embodiment, the carrier wave is frequency-modulated by the composite control signal. Therefore, in the power supply and control device 32a, the control signals from the level variable circuits 136, 138, and 140 of the control unit 134 are combined, and the frequency modulation circuit 162a is combined.
And frequency-modulate the carrier wave by the combined control signal to generate a modulation control signal. This modulation control signal is
It is supplied to the booster 30a as in the first embodiment. In the booster 30a, the modulation control signal is extracted from the superimposed signal by the bandpass filter 196, and the amplitude limiter 2
After the amplitude is limited by 18, the frequency discriminator 204
After being demodulated by a, it is supplied to each of the bandpass filters 206, 208, 210 of the demultiplexing circuit 212, and thereafter, the same processing as in the first embodiment is performed. The reason why frequency modulation is used is as follows. The length of the coaxial cable 76 between the booster 30a and the power supply and control device 32a is shorter than expected, the attenuation in the coaxial cable 76 is small, and the attenuation amount of each state changing means 42, 50, 62 is increased. However, the level of each television broadcast signal supplied to the terminal 90 may be higher than expected. In such a case, an attenuator is inserted between the booster 30a and the power supply and control device 32a. Alternatively, a distributor may be inserted between the coaxial cable 76 and the terminal 90 of the power supply and control device 32a to distribute the output of the booster 30a to other television receivers. In such a case, the level of the modulation control signal transmitted to the booster 30a side also decreases, and when the modulation control signal is an amplitude modulation signal, the level of each control signal demodulated on the booster 30a side also becomes smaller than expected, There is a possibility that the desired gain adjustment cannot be performed. However, when the frequency-modulated modulation control signal is transmitted to the booster 30a side, desired gain adjustment can be performed even if the level of the modulation control signal decreases.

In both of the above-mentioned embodiments, PIN diodes are used as the respective state changing means so that the attenuation amount can be continuously changed. For example, as shown in FIG. 7, one electronic switch or relay 220 is used. It is also possible to use state changing means for changing the amount of attenuation in two steps. Further, it is of course possible to further increase the number of electronic switches to change the attenuation amount in multiple stages. In this case, each level variable circuit 136, 138, 140 may also be configured to change the level of the control signal stepwise by using an electronic switch. Alternatively, as shown in FIG. 8, two electronic switches or relays 222 and 224 are used, and a band elimination filter 226 is inserted between the amplification stages.
It may be configured to remove the interfering wave by switching to a state where it is not inserted. Further, in the above embodiment, the variable attenuator is used as the state changing means, but it is also possible to use the variable gain amplifier. Further, in the above embodiment, the attenuation amounts of the three state changing means are changed, but the attenuation amounts of a larger number of state changing means can be changed by increasing the number of oscillation signals. Further, in the above embodiment, each state changing means is provided in each different amplifier, but the attenuation amount of a plurality of state changing means provided in one amplifier may be adjusted, or the attenuation of the state changing means may be adjusted. In addition to adjusting the amount, the interference wave may be removed by switching between insertion and non-insertion of a band elimination filter provided as a state changing means separately from these state changing means. Further, in the above-described embodiment, the modulation control signal is superimposed on the DC voltage for operating the amplifier, but the modulation control signal can be superimposed on the AC voltage for operating the amplifier .

[0021]

As described above, in the remote control amplifier according to the present invention, the output signal of the amplifying means and the output of the operating power supply are transmitted.
The modulation control signal transmitted on the transmission line is converted into multiple control signals.
Therefore, it differs from the output signal of the amplification means and the output of the operating power supply.
It is a modulation of the carrier of the frequency, and these multiple controls
The control signal also differs from the output signal of the amplification means and the output of the operating power supply.
Different frequencies and different frequencies,
Each bell is adjustable. This modulation control signal
Control signal by demodulating each of the control signals
Signal demultiplexing, that has gained a conditioned signal into. Obey
The output signal of the amplifier and the output of the operating power supply.
In the case where a plurality of state changing means, particularly three or more state changing means are provided, the state changing means can be adjusted individually. Especially, the level of the control signal is adjustable
It is possible to adjust the state changing means in detail according to the level.
Controllable. Further, in the control device according to the present invention, the frequency of the output signal of the amplification means or the output of the operating power supply is increased.
Signals of different frequencies and different frequencies.
Signal level modulated by individually adjusted control signals
Since the modulation control signal is superimposed on the output of the operating power supply,
No influence on the output signal from the width means
Above the power output of the remote control amplifier like the conventional one
It is not necessary to limit to AC power supply, either AC power supply or DC power supply
It can also be controlled by a remote control amplifier operating on
It Moreover, since the modulation control signal can be superimposed on the operating power supply output by mutual inductive coupling, when the modulation control signal is extracted from the superimposed signal of the operating power supply output and the modulation control signal on the remote control amplifier side. , It is not necessary to use a high frequency choke with a large DC resistance, and no voltage drop occurs in the power output. In addition, an unbalanced attenuator with an asymmetrical constant selected is used as a mutual induction circuit and a modulation control signal generator.
Since the impedance control is performed by being provided between the stage and the stage , harmonic leakage of the modulation control signal does not occur.
Further, since <br/> capable are use a frequency modulation circuit to the transmission means, even if the attenuation of the modulation control signal in the transmission line, it is possible to better control the state varying means.

[Brief description of drawings]

FIG. 1 is a block diagram of a first embodiment of a remote control amplifier and its control device according to the present invention.

FIG. 2 is a circuit diagram showing an example of a state changing means used in the first embodiment.

FIG. 3 is a detailed block diagram of an oscillator, a controller and a modulator used in the first embodiment.

FIG. 4 is a diagram showing frequencies and levels of modulation control signals used in the first embodiment.

FIG. 5 is a detailed block diagram of a demodulation unit and a demultiplexing conversion unit used in the first embodiment.

FIG. 6 is a block diagram of the second embodiment.

FIG. 7 is a circuit diagram showing another example of the state changing means used in the both embodiments.

FIG. 8 is a circuit diagram showing still another example of the state changing means used in the both embodiments.

FIG. 9 is a circuit diagram of a conventional remote control amplifier and its control device.

[Explanation of symbols]

 30 booster 32 power supply and control device 42 50 62 state changing means 74 output terminal 88 demultiplexing conversion unit 92 superposition circuit 112 oscillation unit 134 control unit

Claims (7)

(57) [Claims] 1. A signal condition according to the level of a status adjustment signal.
A plurality of state changing means for changing the state,
Is output to the transmission line, and the output of the operating power source and the modulation control signal for this amplifier are
It is superposed and input via the above transmission line.
The modulation control signal is extracted from the superposed signal and the modulation control signal is extracted.
The control signal is a composite signal and the output signal of the amplifying means and the above
With the signal that modulated the carrier of the frequency different from the operating power output
Yes, the combined signal is the output signal of the amplification means and the
The frequency is different from that of the operating power supply output, and
The same number as the above-mentioned state changing means, which have different frequencies.
Extraction means that is a combination of control signals, demodulation means that demodulates the extracted modulation control signal into the composite signal, and the state adjustment after demultiplexing the demodulated composite signal into the control signals A remote control amplifier, comprising: a demultiplexing conversion unit that converts the signal into a corresponding state variable unit. 2. A signal is internally transmitted according to the level of a status adjustment signal.
Has a plurality of status change means for changing the status of the
Generates an operating power supply output to a remote control amplifier that outputs the signal via the transmission line, and outputs the signal via the transmission line.
Different from the operating power supply output generating means for supplying to the remote control amplifier, the output signal of the amplifying means and the operating power supply output.
Frequency and different frequencies.
The oscillation means for generating the same number of oscillation signals as the state varying means, the control signal generation means for individually adjusting the level of each of the oscillation signals to generate the control signal, and the combined signal of the control signals for amplification Amplitude change of carrier wave of different frequency from the output signal of
A modulation control signal generating means for generating a modulation control signal tone or frequency modulation to, you output to the transmission line the modulated control signal to transmit to the remote control amplifier in superposition to the operating power supply output A control device for a remote control amplifier, comprising: superimposing means. 3. The control device for a remote control amplifier according to claim 2, wherein the superimposing means superimposes the modulation control signal on the output of the operating power supply by mutual inductive coupling. . 4. The control device for a remote control amplifier according to claim 3, wherein an unbalanced attenuator is provided between the superposing means and the modulation signal generating means . 5. A signal condition according to the level of a status adjustment signal.
An amplifying means having a plurality of state changing means for changing the state, a transmission line through which an output signal of the amplifying means is transmitted, and a transmission line provided on the opposite side of the transmission line from the amplifying means and supplied to the transmission line. said the operating power output generating means for generating an operating power supply output for amplification means, provided we are in the operating power output generating means side, said amplifying means for
Output signal and the frequency different from the above operating power supply output.
And the above-mentioned variable state hand having different frequencies
Oscillator means for generating the same number of oscillating signals as the number of stages, control signal generating means for individually adjusting the level of each oscillating signal to generate a control signal, and a composite signal of the control signals for the amplifying means. Transmission means for modulating a carrier wave having a frequency different from that of the output signal and the output of the operating power supply to generate a modulation control signal, superimposing it on the output of the operating power supply and transmitting it to the amplifying means side by the transmission line, and the amplifying means side Demodulation means for demodulating the modulation control signal from the superimposed signal of the operating power supply output and the modulation control signal transmitted through the transmission line to demodulate the modulation control signal into the composite signal; A remote control amplifier, which demultiplexes the synthesized signal into the control signals, converts the demultiplexed signals into the state adjustment signals, and supplies the demultiplexed state signals to the corresponding state changing means. The control device of the benefactor. 6. The remote control amplifier and its control device according to claim 5, wherein said transmission means has amplitude modulation means .
Remote control amplifier and a control system, characterized in Rukoto. 7. The remote control amplifier and the control device therefor according to claim 5, wherein said transmission means has frequency modulation means .
A remote control amplifier and its control device.