JPH0227817A - Hot standby transmission system - Google Patents

Abstract

PURPOSE:To relieve the load of a switch and an isolator, to reduce the difficulty in the heat radiation and high output reflection absorbing countermeasures and to reduce the power consumption of an amplifier by reducing a transmitter output in the standby state. CONSTITUTION:Suppose that a line at the side of a modulator 20 is active and a lone for a modulator 30 is a standby, then an amplifier 21 of the active line is controlled to be in the standard operation by an amplifier control circuit 28, the signal is amplified up to the standard level and a switch 23 is closed. On the other hand, the amplifier 31 of the standby circuit is controlled to decrease its output by an amplifier control circuit 38 and the signal is amplified at only a lower level than the standard level and since the switch 33 is opened, the signal is reflected and absorbed by an isolator 32. Thus, the load of the switch and the isolator is relieved, and the difficulty of the heat dissipation and high output reflection absorption countermeasures of the radiators and the isolators is reduced and the power consumption of the amplifier in the standby state is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hot stun I transmission system in which two transmitter outputs, a working and standby transmitter, are selected and transmitted by a switch.

In particular, it relates to control of transmission output in a circuit on the standby side.

[Prior Art] FIG. 2 shows a block diagram of a conventional hot standby transmission system.

In the figure, the signal of the working line is output from a modulator 1, passes through an amplifier 2, an isolator 3, a switch 4, a circulator 5, and an antenna 6 before being sent out. 7 is a detector,
8 is a comparator, and 9 is a control circuit.

The standby circuit, like the working circuit,
Modulator 11. Amplifier 12. Isolator 13, switch 1
4. Detector 17. and a comparator 18.

And switching between the working and standby transmitter outputs is as follows:
The control circuit 9 performs this by switching the switches 4 and 14.

In this conventional hot standby transmission method,
The transmitter (standby circuit) in the standby state outputs the same level of transmission output as the transmitter during line operation, opens the switch 14 in the output stage of the transmitter under the control of the control circuit 9, and reflects the output. By absorbing this with the isolator 13, the transmission output of the transmitter in the standby state was cut off.

[Problems to be Solved] In the conventional system described above, the output of the transmitter in the standby state is absorbed by the isolator, which results in a high output load being applied to the switch and the isolator.

For this reason, the radiator needs to be made larger as a heat dissipation measure, and power that would otherwise be unnecessary is consumed by the amplifier.

The present invention has been made in view of the above-mentioned problems.
To provide a hot standby transmission method that can reduce the load on switches and isolators, thereby reducing the need for heat dissipation measures for radiators and isolators as well as high-output reflection and absorption measures, as well as reducing the power consumption of amplifiers in standby mode. purpose.

[Means for Solving the Problem] In order to achieve the above object, the present invention provides a working and standby system each having a modulator, an amplifier for amplifying the output from the modulator, and an isolator for passing the output from the amplifier. In a hot standby transmission system in which the output from two transmitters is selected by a switch and transmitted, an amplifier control circuit is provided to control the output of the standby amplifier to be lowered.

[Example] An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention.

In the figure, there are two transmitters, a working one and a backup one.

modulator 20.30 and this modulator 20.30, respectively.
an amplifier 21.31 that amplifies the output from the amplifier 21.31, and an isolator 22 that passes the output from the amplifier 21.31.
．． 32 and a switch 23°33.

And switching between the working and standby transmitter outputs is as follows:
The control circuit 40 does this by switching the switches 23.33.

Further, in both the working system and the standby system, the amplifier 21.31
an amplifier control circuit 28,38 for controlling the operation of the comparator 26, forming a circuit for monitoring the transmit power;
36, and detectors 27 and 37. The operation of the amplifier control circuit 28.38 is controlled by the control circuit 40, and the reference level of the comparator 26.36 is set by the control circuit 40. In addition, each comparator 26
．． The output of 36 is input to a control circuit and monitored.

Now, in this embodiment, the line on the modulator 20 side is currently in use,
Assuming that the line on the R unit 30 side is in standby, the signal on the working line is output from the modulator 20 and sent out through the amplifier 21 → isolator 22 → switch 23 → circulator 24 → antenna 25. .

At this time, the amplifier 21 is controlled by the amplifier control circuit 28 to perform standard operation. Therefore, the @ signal is amplified to the standard level, and the switch 23 is also closed.

Furthermore, in order to monitor the transmission output, the reference level of the comparator 26 is set to the standard, and compared with the detection output of the wave detector 27.

On the other hand, the signal of the standby circuit is output from the modulator 3o, but the amplifier 31 is controlled by the amplifier control circuit 38 to perform standby operation, that is, to lower the output.

Therefore, the signal is amplified only to a level lower than the standard level, and since the switch 33 is also open, it is reflected once and absorbed by the isolator 32. At this time, the reference level of the comparator 36 for monitoring the transmission output is set to the standard during standby, and is compared with the detection output of the detector 37.

[Effects of the Invention] As explained above, the present invention reduces the output of the transmitter in the standby state to lighten the load on the switch and isolator, thereby providing heat dissipation measures for radiators and isolators as well as high output reflection and absorption measures. This has the effect of reducing the power consumption of the amplifier in standby mode.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a hot standby transmission method according to the present invention, and FIG. 2 is a block diagram of a conventional hot standby transmission method. 30: Modulator 31 Amplifier 32 Near isolator 33: Switch 24: Circulator 25: Antenna 26, 38: Comparator 27.37: Detector 28, 38: Amplifier control circuit 40: Sub-prize circuit

Claims (1)

[Claims] Each transmitter has a modulator, an amplifier that amplifies the output from the modulator, and an isolator that passes the output from the amplifier. A hot standby transmission method characterized in that the standby transmission method is provided with an amplifier control circuit that controls the output of a standby amplifier to be lowered.