JPH04313923A - Remote control amplifier and its controller - Google Patents

Abstract

PURPOSE:To adjust the signal level of plural state variable means based on a control signal superimposed individually onto a DC or an AC power supply individually. CONSTITUTION:The output signal of a booster 30 having three state variable means 42, 50, 62 whose signal level is respectively adjusted in response to the level of a state adjustment signal is transmitted through a coaxial cable 76. A DC voltage is fed to the booster 30 from a smoothing circuit 106 via the coaxial cable 76. Each control signal obtained by frequency-shifting each of oscillation signals having three frequencies whose center frequency differs from each other at a control section 110 individually respectively is fed to the booster 30 via the coaxial cable 76, a branching conversion section 88 provided on the booster 30 branches respectively each control signal and converts the result into each gain adjustment signal having a level in response to each frequency shift and it is fed to the state variable means 42, 50, 62, thereby changing the signal level.

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 variable means included in an amplifier, such as a variable attenuator, from a remote location, and more particularly to a device for controlling a plurality of state variable means.

0002

[Prior Art] Conventionally, as a device for remotely controlling an amplifier from a remote location as described above, a television broadcast signal received by an antenna installed outdoors is amplified by an amplifier installed on the antenna support. In some cases, the gain of this amplifier is controlled remotely indoors. 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 voltage generated on the secondary side of the power transformer 2 is taken out by a diode 4, its level is adjusted by a variable resistor 6, and it is used as a gain adjustment voltage. It is combined at a connection point 10 with the operating voltage consisting of a negative half wave taken out by 8, and transmitted to the variable gain amplifier 16 side via a high frequency blocking coil 12 and a transmission line 14. The negative half wave of the transmitted voltage is
The signal is rectified and smoothed from the high frequency blocking coil 18 by a rectifying and smoothing circuit including a diode 20 and a capacitor 22, and is supplied to the power supply terminal 23 of the variable gain amplifier 16. On the other hand, the positive half wave whose level is adjusted on the power supply side is rectified and smoothed from the high frequency blocking coil 18 in a rectifying and smoothing circuit consisting of a diode 24 and a capacitor 26, and is then passed through the gain control voltage input terminal 28.
supplied to Therefore, the gain of the variable gain amplifier 16 is adjusted to a gain corresponding to the value adjusted by the variable resistor 6.

0003

However, with the above-mentioned device, it is only possible to adjust the gain of one variable gain amplifier. As shown in Japanese Patent Publication No. 61-54292, even if the positive half-wave and negative half-wave of AC are respectively used as gain adjustment voltages, the gains of only two amplifiers can be adjusted. . There are two types of television broadcast signals: UHF band and VHF band.
The band is divided into low channel and high channel. Therefore, an amplifier is provided for each of these three bands,
When attempting to control these gains from a remote location, there is a problem in that the above-mentioned device cannot be implemented. Note that if you want to control the gains of multiple amplifiers to be the same, you can also use the device described above, but in the case of amplifiers that amplify different bands as described above, each amplifier requires Since the gains obtained are often different, it is practically impossible to use the above-mentioned device. Further, in the above-mentioned device, it is assumed 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.

[0004] The present invention allows a plurality of state variable means, particularly three or more state variable means, to be individually controlled from a remote location, and furthermore, the amplifier having the state variable means can be used to control the supply of either DC power or AC power. It is an object of the present invention to provide a remote control amplifier and its control device that can be used even if it is a receiver type.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the remote control amplifier of the present invention is an amplifier having a plurality of state variable means for respectively adjusting the state of a signal according to the level of a state adjustment signal. and a terminal connected to the line. The operating power supply for the amplifying means is input to this terminal via the line, and a plurality of control signals for each of the state variable means are input via the line. Each of the control signals has a different fundamental frequency corresponding to each of the state variable means, and each frequency is individually shifted from each of the fundamental frequencies. The remote control amplifier of the present invention further separates each of the control signals inputted from the terminal, and provides each of the state adjustment signals having a level corresponding to the frequency shift of each of the separated control signals. A demultiplexing conversion means is also provided for converting the signal into a signal and supplying it to each of the corresponding state changing means. Further, the control device according to the present invention has the same number of means for generating a power output for the amplification means as the plurality of state variable means provided in the amplification means, and generates a plurality of oscillation signals each having a different fundamental frequency. means for generating each control signal by individually deviating from the fundamental frequency; and a superimposing means for superimposing the power output of the power supply means and each control signal and supplying the superposed signal to a line connected to the amplification means. It is equipped with.

[0006]

According to the present invention, in the control means of the control device, each oscillation signal is individually shifted in frequency from each fundamental frequency, superimposed on the power supply output, and transmitted to the amplification means. On the amplification means side, the demultiplexing conversion means demultiplexes each control signal, converts it into a state adjustment signal of a level corresponding to the frequency deviation from the fundamental frequency, and supplies it to the corresponding state variable means. Therefore, the state of the signal in each state variable means can be adjusted individually, and each amplification means can be adjusted to be variable.

[0007]

[Embodiment] As shown in FIG. 1, this embodiment consists of a so-called booster 30 and its power supply and control device 32.
It amplifies the HF band television broadcast signal and the UHF band television broadcast signal, and the VHF band television broadcast signal input from the input terminal 34 is sent to the branching filter 36.
The signal is split into a low channel television broadcast signal VL and a high channel television broadcast signal VH. The low channel television broadcast signal VL is
The signal is amplified by a low channel amplifier 44 provided with a state variable means 42 between the front stage amplifier section 38 and the rear stage amplifier section 40 . Similarly, high channel television broadcast signal VH
is amplified by a high channel amplifier 52 including a state variable means 50 between the front stage amplifier section 46 and the rear stage amplifier section 48. The thus amplified low channel television broadcast signal VL and high channel television broadcast signal VH are mixed in a mixer 54. Also,
The UHF band television broadcast signal inputted from the input terminal 56 is passed through a bandpass filter 58 and a preamplifier 60.
, state variable means 62, middle stage amplification section 64, rear stage amplification section 66
The signal is amplified by a UHF amplifier 68 equipped with a UHF amplifier 68. This amplified UHF band television broadcast signal is mixed with the VHF band television broadcast signal from the mixer 54 by the mixer 70, and the capacitor 72 of the superimposition circuit 71
is supplied to the output terminal 74 via a line, for example a coaxial cable 76, to the power supply and control device 32.

The state changing means 42, 50, 62 include:
For example, a variable attenuator 78 as shown in FIG. 2 can be used. This variable attenuator 78 is connected to the PIN diode 8
0, its cathode side is grounded via a resistor 82, and a DC voltage is supplied to its anode side via a resistor 84, and by changing this DC voltage, the PIN
By changing the high frequency resistance value of the diode 80, the amount of attenuation of the high frequency signal flowing from the cathode side to the anode side of the PIN diode 80 is changed. Note that 86 is a bypass capacitor, and a DC voltage for controlling the amount of attenuation is provided from a branching converter 88, which will be described later.

Returning to FIG. 1 again, 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 superimposition circuit 92. It is supplied to a terminal 96 via a capacitor 94 of this circuit 92. Since this terminal 96 is connected to, for example, a television receiver, the UHF band and VH band amplified by the booster 30
An F-band television broadcast signal is supplied to a television receiver.

The power supply and control device 32 has a transformer 98 that transforms a commercial AC voltage, and the AC voltage induced on the secondary side of the transformer 98 is rectified by a rectifier circuit 100 and further connected to a capacitor 102. A smoothing circuit 106 consisting of a high frequency choke 104 converts the voltage into a DC voltage, which is supplied to the output terminal 74 of the booster 30 via the high frequency blocking coil 108 of the superimposing circuit 92, the terminal 90, and the coaxial cable 76.

The power supply and control device 32 has a control section 110, and the control section 110 has basic oscillation frequencies of, for example, 4.75 KHz, 38 KHz, and 304 KH.
z and has a frequency relationship of 8 times, and the state variable means 42
, 50, and 62, three variable frequency oscillation circuits 112.
, 114, 116. This oscillation circuit 112 includes three inverters 118 and 120, as shown in FIG.
, 122, a resistor 124, a variable resistor 126, and a capacitor 128.
6. The value of capacitor 128 is such that the basic oscillation frequency is 4.7.
5KHz, and by changing the resistance value of the variable resistor 126, the oscillation frequency can be changed to, for example, ±
It is configured to shift by 2.0KHz. This oscillation signal is output through a low-pass filter 130 to prevent generation of unnecessary harmonics. Oscillation circuit 1
14 and 116 have similar configurations, so a detailed explanation will be omitted, but the basic oscillation frequencies are 38 KHz and 38 KHz, respectively.
04KHz, and the frequency deviation is ±16K, respectively.
Hz, ±150KHz. The frequency deviations of these oscillation signals are adjusted so that the highest frequency of the oscillation circuit 112 and the lowest frequency of the oscillation circuit 114 do not overlap.
are selected so as not to overlap with the lowest frequency. This state is shown in FIG.

Each variable frequency oscillation circuit 112, 114, 1
The 16 oscillation signals are connected to capacitors 132 and 134, respectively.
, 136 to a predetermined level by attenuators 138, 140, 142.
140 and 142 to each other, and as shown in FIG.
44, is supplied to the terminal 90 via the high frequency blocking coil 108, and from there to the booster 30 via the coaxial cable 76.
is supplied to the output terminal 74 of. That is, a signal in which three frequency-shifted oscillation signals are superimposed on a DC voltage is transmitted from the power supply and control device 32 to the booster 30 via the coaxial cable 76. The high frequency blocking coil 108 of the superimposing circuit 92 has a value such that it exhibits low impedance to the DC voltage from the smoothing circuit 106 and the oscillation signal from the control unit 110, and high impedance to the high frequency signal from the booster 30. The capacitor 94 is connected to the DC voltage from the smoothing circuit 106 and the control unit 1
exhibits high impedance to the oscillation signal from 10,
The capacitor 144 is selected to have a low impedance to the high frequency signal from the booster 30, and the capacitor 144 is selected to have a high impedance to the DC voltage from the smoothing circuit 106. The value is selected to exhibit a low impedance.

The superimposed signal transmitted via the coaxial cable 76 is supplied to the demultiplexing converter 88 within the booster 30 via the high frequency blocking coil 146 of the superimposing circuit 71. The DC voltage of this superimposed signal is passed through a high frequency choke 147 to a resistor 148 and a capacitor 1 as shown in FIG.
50, each amplification stage 38, 40, 46, 48, 60, shown in FIG.
64 and 66 as an operating DC voltage. The high frequency blocking coil 146 of the superimposing circuit 71 is selected to have a value that exhibits a low impedance to the superimposed signal and a high impedance to the high frequency signal from the mixer 70, and the same capacitor 72 has a high impedance to the superimposed signal. is selected to exhibit a low impedance to the high frequency signal from the mixer 70.

A composite signal of the three oscillation signals of the superimposed signal is generated across a resistor 154 via a capacitor 152, and is supplied to band amplifiers 156, 158, and 160. Bandwidth amplifier 156 includes transistor 162,
164 and two resonant circuits 166, 168.As shown in FIG. The resonance frequency is set. Therefore, an output is generated across the emitter resistor 170 of the transistor 164, which has the highest output level when the oscillation signal with a center frequency of 4.75 KHz has the highest frequency, and has the lowest output level when the center frequency has the lowest frequency. This output is rectified and smoothed by a rectifying and smoothing circuit 176 consisting of a diode 172 and a capacitor 174, and is converted into a DC voltage. This DC voltage is applied to the variable gain means 4
2 as a control voltage.

The other band amplifiers 158 and 160 are similar to the band amplifier 156, except that the resonant frequencies of their built-in resonant circuits are set slightly higher than the highest frequency of the oscillation signal with center frequencies of 38 KHz and 308 KHz, respectively. The detailed explanation will be omitted. The outputs of these band amplifiers 158 and 160 are also converted into DC by rectifying and smoothing circuits 178 and 180, and are supplied as control voltages to the corresponding state variable means 50 and 62.

The frequency of the oscillation signal having a center frequency of 4.75 KHz is shifted by the variable frequency oscillation circuit 112, and the frequency of the oscillation signal having a center frequency of 4.75 KHz is shifted, and the frequency of the oscillation signal is shifted by the frequency variable oscillation circuit 112.
56 changes, and in accordance with this change, the attenuation amount of the state variable means 42 and, in turn, the gain of the VHF band low channel amplifier 44 are adjusted. Similarly, the state variable means 5
0 attenuation, and therefore VHF band high channel amplifier 5
The gain of 2 corresponds to the frequency deviation of the center frequency of 38 KHz in the frequency variable oscillation circuit 114, and similarly, the attenuation amount of the state variable means 62, and hence the gain of the UHF amplifier 68, depends on the frequency deviation of the frequency variable oscillation circuit 114. This corresponds to the frequency shift of the oscillation signal whose center frequency is 304 KHz. In this way, in this embodiment, even if three amplifiers are provided, the gain of each amplifier can be adjusted individually.

In the above embodiment, a PIN diode is used as each state variable means to continuously change the amount of attenuation. However, as shown in FIG. 7, for example, one electronic switch or relay 182 may be used. It is also possible to use state variable means that changes the amount of attenuation in two stages. Furthermore, it is of course possible to further increase the number of electronic switches and change the amount of attenuation in multiple stages. In this case, each of the variable frequency oscillation circuits 112, 114, and 116 may also shift the frequency in stages using electronic switches. Alternatively, as shown in FIG. 8, two electronic switches or relays 184 and 186 are used to switch between a state in which a band-removal filter 188 is inserted between the amplification stages and a state in which it is not inserted, thereby removing the interference waves. It may be configured as follows. Further, in the above embodiment, a variable attenuator is used as the state variable means, but a variable gain amplifier may also be used. Further, in the above embodiment, the attenuation amounts of three state variable means are changed, but by increasing the number of oscillation signals, the attenuation amounts of even more state variable means can be changed. Further, in the above embodiment, each state variable means is provided in a different amplifier, but the attenuation amount of a plurality of state variable means provided in one amplifier may be adjusted, or the attenuation of the state variable means may be adjusted. In addition to adjusting the amount, interference waves may also be removed by switching between insertion and non-insertion of a band elimination filter provided as a state variable means separately from these state variable means. Further, in the above embodiments, the oscillation signal is superimposed on the DC voltage for operating the amplifier, but the oscillation signal may also be superimposed on the AC voltage for operating the amplifier. Furthermore, in the above embodiment, the operating voltage and the oscillation signal for gain adjustment are superimposed on the output signal from the amplifier, but only the operating voltage and the oscillation signal for gain adjustment are superimposed on the output signal from the amplifier. It may be superimposed on a line different from the transmission line of the output signal.

[0018]

As described above, in the remote control amplifier according to the present invention, the signals obtained by individually shifting the frequencies of signals having different fundamental frequencies are converted to a level corresponding to each frequency shift, and an adjusted signal is obtained. Therefore, when a plurality of state variable means, particularly three or more state variable means are provided, each of these state variable means can be adjusted individually. Also,
In the control device according to the present invention, the control signals each having the level of the signal having a different fundamental frequency individually adjusted,
Since it is superimposed on the power output, there is no need to limit the power output of the remote control amplifier to AC power unlike conventional ones, and the gain can be controlled for remote control amplifiers that operate on either AC or DC power. Can be done.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an 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 state variable means used in the same embodiment.

FIG. 3 is a detailed block diagram of a control section used in the same embodiment.

FIG. 4 is a diagram showing the frequency and level of a control signal used in the same embodiment.

FIG. 5 is a detailed block diagram of a demultiplexing/converting section used in the same embodiment.

FIG. 6 is a frequency characteristic diagram of a band amplifier used in the demultiplexing/converting section of the same embodiment.

FIG. 7 is a circuit diagram showing another example of state variable means used in the same embodiment.

FIG. 8 is a circuit diagram showing still another example of state variable means used in the same embodiment.

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 variable means 74 Output terminal 88 Demultiplexing conversion section 92 Superimposition circuit 110 Control section

Claims (3)

[Claims] Claims: 1. Amplifying means having a plurality of state variable means for respectively adjusting the state of a signal according to the level of a state adjustment signal; and an amplifying means connected to a line, the operating power of the amplifying means being inputted via the line. and a terminal into which a plurality of control signals for each of the state changing means are inputted via the line, and each of the control signals has a different fundamental frequency corresponding to each of the state changing means. Each frequency is individually shifted from each fundamental frequency, and each of the control signals inputted from the terminal is demultiplexed, and the frequency of each of the demultiplexed control signals is A remote control amplifier comprising a branching conversion means for converting the state adjustment signals into the state adjustment signals having levels corresponding to the deviations and supplying the signals to the corresponding state variable means. 2. Means for generating a power output for amplifying means of a remote control amplifier located at a remote location;
means for generating each control signal by individually shifting a plurality of oscillation signals having different fundamental frequencies from the fundamental frequency, the same number as the plurality of state variable means provided in the amplifying means; A control device for a remote control amplifier, comprising: superimposing means for superimposing a power supply output and each of the control signals and supplying the superposed signal to a line connected to the remote control amplifier. 3. An amplification means comprising a plurality of state variable means each adjusting the state of a signal according to the level of a state adjustment signal, a transmission line for transmitting an output signal of the amplification means, and a transmission line for transmitting an output signal of the amplification means. A power supply provided on the opposite side of the amplification means to supply operating power to the amplification means via the transmission line, and a power supply provided on this power supply side that individually deviates oscillation signals of different fundamental frequencies from the fundamental frequency. control signal supply means for supplying each of the control signals to the amplifying means via the transmission line; A remote control amplifier and its control device, comprising a branching conversion means that converts the level into each of the above-mentioned state adjustment signals and supplies them to the corresponding each of the above-mentioned state variable means.