JPH01241228A - Signal repeater - Google Patents

Abstract

PURPOSE:To improve the reliability in a way that the cause of a fault does not give effect onto two relay circuits at the same time by devising the repeater so that a rectifier element is interposed to each power supply line for the duplicated relay circuits with the same configuration in a way of being biased in the opposite energizing directions, thereby activating the elements alternatively. CONSTITUTION:If an amplifier 2 is failed and it is detected by a receiver 4, the polarity of a power voltage with respect to power cables L3, L4 is inverted, then the amplifier 3 is transited to the operating state and a transmission signal is supplied to the receiver 4 via a hybrid circuit (T1, R1) and signal cables L9, L10. The polarity of the power voltage is controlled in such a way to activate one relay circuit independently of the state of the other relay circuit, thereby preventing the entire repeater from going to an inactivating state. Moreover, the number of signal cables is decreased and the entire cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a signal relay device inserted into a signal cable in a signal transmission system such as a remote monitoring system and a wired communication system.

[Prior Art] Conventionally, for example, in a remote monitoring system that detects and monitors the operating status of various devices at a remote location, signals from a sensor attached to a detection target are transmitted to a control and monitoring device installed at a remote location. In order to transmit signals accurately, a signal repeater may be inserted in the middle of the signal cable in consideration of the adverse effects of the transmission distance, such as signal attenuation and noise mixing.

By the way, some signal transmission systems have signal cables installed underwater or underground, and in such systems, signal relay devices are also installed underwater or underground. Therefore, even if a failure occurs in the signal relay device, maintenance and inspection cannot be easily performed. Furthermore, depending on the signal transmission system, it is desired that signal transmission be performed continuously at all times. That is, there are cases where a communication interruption accident due to a failure of a signal relay device or the like may lead to a functional outage of the entire system.

In such a system, it is desired that the signal relay device itself has very high reliability, and for this reason conventionally, the second
As shown in the figure, a signal relay device is used in which the relay circuit is duplicated to improve reliability.

In FIG. 2, a pair of input terminals T1 of the signal relay device 1
and T2 are connected to signal cables extending from transmitting devices (not shown) such as measurement sensors and communication devices, and signals input to these input terminals T1 and T2 are transmitted via signal lines L1 and L2. The signal is then input to two amplifiers 2 and 3, which serve as relay circuits and are connected in parallel. Each amplifier 2.3 is supplied with positive and negative power supply voltages from the receiving device 4 via power cables L3 and L4, and performs an amplifying operation upon receiving the supplied power supply voltages.

The transmission signals amplified by each amplifier 2.3 are provided to the receiving device 4 via a pair of signal cables L5 and L6, L7 and L8, respectively. These pairs of signal cables L5 and L6, L7 and L8 are connected to switching input terminals Sla and S2a, Slb and S2b of a pair of interlocking switches S1 and S2 of two-man power one output lift in the receiving device 4, The output signal from one amplifier 2.3 is taken into the receiving device 4 by the interlocking switching operation of these switches S1 and S2.

Here, the switches S1 and S2 normally select the amplifier 2, and when the receiver 4 detects that the amplifier 2 has failed and no signal arrives, the switches S1 and S2 select the output signal of the other amplifier 3. It is designed so that it can be switched so that the

[Problems to be Solved by the Invention] However, in the conventional signal relay device 1 as described above, when a surge voltage or the like occurs in the power cables L3 and L4, the power cables L3 and L4 are common to the two amplifiers 2.3. Since the surge voltage is applied to both the amplifiers 2 and 3 at the same time, this surge voltage causes the two amplifiers to
were destroyed at the same time, and there was a fear that the duplication would become meaningless.

Furthermore, if a breakdown occurs in the amplifier 2 that is in selective operation due to various reasons and the power supply is short-circuited within this amplifier 2, the power supply to the other amplifier 3 will be stopped and this amplifier 3 will be interrupted. There was a problem in that the high reliability provided by duplication could not be enjoyed because the system was rendered inoperable.

Furthermore, the conventional signal relay device 1 described above requires a total of six pulls for power and signals, which requires a large amount of cables to be laid, which increases the risk of failure. , the installation work was complicated.

The first invention has been made in consideration of the above points, and
It is more reliable because it prevents the cause of failure in one duplex relay circuit from affecting the other relay circuit, and also prevents various causes of failure, such as surge voltage to the power cable, from affecting both relay circuits at the same time. The present invention aims to provide a signal relay device with high performance.

In addition, the second invention provides a signal relay device that can output the output signal from the duplicated relay circuit to the receiving device via a pair of signal cables, thereby reducing the number of signal cables. This is what we are trying to provide.

[Means for solving the problem] In order to solve the problem, in the first invention,
A signal relay device comprising first and second relay circuits having the same configuration that perform predetermined signal processing on an input signal, and transmitting an output signal from the negative relay circuit to a destination device,
A rectifying element is placed on the power supply line to the first relay circuit branched from the external power cable so that the rectifying element is biased in the forward direction with respect to the first power supply voltage, and The rectifying element was inserted so as to be biased in the opposite direction with respect to a second supply voltage obtained by inverting the first supply voltage. Further, another rectifying element is placed on the power supply line branched from the power cable to the second relay circuit so that the rectifying element is biased in the opposite direction with respect to the first supply power voltage, and The rectifying element was inserted so as to be biased in the forward direction with respect to the second supply power voltage. The second relay circuit is brought into a rest state with respect to the first supply power voltage at which the first relay circuit is in an operating state, and the second relay circuit is brought into a rest state with respect to a second supply power voltage at which the second relay circuit is in an operating state. The first relay circuit is placed in a dormant state.

Further, in the second invention, the power supply configuration for the first and second relay circuits is configured similarly to the first invention, and the output signal from the first relay circuit and the second relay circuit are connected to each other. The output signal from the transmitter is outputted to the transmission destination device via a signal coupling circuit and a single pair of output cables.

[Function] In the first aspect of the invention, the rectifying element inserted on the power supply line to the first relay circuit is biased in the forward direction with respect to the first supply voltage, so that the power supply current is 1st
It flows into the power supply terminal of the relay circuit and becomes operational. At this time, other rectifying elements connected to the second relay circuit are biased in the opposite direction, so that the power supply current does not flow into the power supply terminal of this second relay circuit and the second relay circuit enters a resting state.

On the other hand, when the supplied power supply voltage is reversed, the first relay circuit, which has been in an operating state, reverses the bias direction of the rectifying element and becomes in the opposite direction, so the power supply current does not flow into it and the first relay circuit goes into a dormant state. . On the other hand, the second relay circuit, which has been in a dormant state until now, has the bias direction of the other connected rectifying elements reversed and becomes a forward direction, so that the power supply current flows into the second relay circuit and the second relay circuit becomes in an operating state.

By controlling the direction in which the power supply voltage is applied in this way, one relay circuit can always be kept in an operating state regardless of the state of the other relay circuit.

In the second aspect of the invention, the output signals from the first or second relay circuit, which are selectively activated by such a power supply configuration, are transmitted through the signal coupling circuit to form a single pair of signals. I made it output to the cable.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of a signal relay device according to this embodiment, and corresponding parts to those in FIG. 2 are denoted by the same reference numerals and their explanation will be omitted.

In FIG. 1, one output terminal of the amplifier 2 is connected to one end TRa of the first winding Lll provided on the primary side of the coupling transformer TR via the signal line E1, and the other output terminal is connected to the signal line E1. It is connected to the other end TRb of the first winding Lll via E2 and a resistor R1. In this way, the amplified transmission signal by the amplifier 2 is transmitted to the second winding L20 provided on the secondary side of the transformer TR.

Also, one output terminal of the other amplifier 3 is connected to the signal line E.
3 to one end TRd of the third winding L12 provided on the primary side of the coupling transformer TR, and the other output terminal is connected to the third winding L1 through the signal line E4 and resistor R1.
2 is connected to the other end TRc. In this way, the amplified transmission signal by the amplifier 3 is transmitted to the second winding L20 of the coupling transformer TR.

Therefore, in this embodiment, a hybrid circuit is constructed by the coupling transformer TR and the resistor R1.

Both ends TRe, TR of the second winding L20 of the coupling transformer TR
f is connected to the output terminal of the signal relay device 1o and further connected to the receiving device 4 via a pair of signal cables L9 and Llo, and supplies the transmission signal amplified by the amplifier 2 or 3 to the receiving device 4. It is done like this.

In this embodiment, not only the above-described relay configuration but also the configuration for supplying the power supply voltage to the first and second amplifiers 2 and 3 are different from the conventional device.

A positive power supply terminal of one amplifier 2 is connected to a cathode terminal of a diode D1, and an anode terminal of this diode D1 is connected to one power supply cable L3 via a power receiving terminal T3 of the signal relay device 10. Further, the negative power terminal of the amplifier 2 is connected to the anode terminal of the diode D2, and the cathode terminal of the diode D2 is connected to the other power cable L4 via the other power receiving terminal T4 of the signal relay device 10. That is, when the power supply voltage through the power cable L3 is a positive voltage and the power supply voltage through the power cable L4 is a negative voltage, the diode D1
and D2 are forward biased, and conversely, when the power supply voltage through the power cable L3 is a negative voltage and the power supply voltage through the power cable L4 is a positive voltage, the diodes D1 and D
2 are connected so that they are biased in the opposite direction.

In addition, the positive power supply terminal of the other amplifier 3 is connected to the diode D.
The anode terminal of this diode D3 is connected to one power cable L4 extending from the receiving device 4 via a power receiving terminal T4.

Further, the negative power terminal of the amplifier 3 is connected to the anode terminal of a diode D4, and the cathode terminal of this diode D4 is connected to the other power cable L3 via the other power receiving terminal T3. That is, power cable L3
When the power supply voltage across power cable L4 is a positive voltage and the power supply voltage across power cable L4 is a negative voltage, diodes D3 and D4 are biased in the opposite direction; , the diodes D3 and D4 are connected to be biased in the forward direction when the power supply voltage via the power supply cable L4 is a positive voltage.

In the above configuration, in the initial state, the power cable L
When the supply voltages at 3 and R4 are respectively positive and negative, diodes D1 and D2 are forward biased, while diodes D3 and D4 are reverse biased, so that the - amplifier 2 operates. state, the other amplifier 3 enters a rest state (operation standby state), and the transmission signal amplified by the amplifier 2 is given to the signal cable L9 and LIO via the hybrid circuit consisting of the resistor R1 and the coupling transformer TR, and the receiving device 4.

During such a transmission operation, if an abnormal voltage such as a surge voltage is applied from the outside to the power cables L3 and R4, the amplifier 2, which is supplied with power via the forward biased diodes D1 and D2, will , an excessive current may be supplied due to the abnormal voltage and the device may be destroyed. Note that even in such a case, the amplifier 3 will not be destroyed because the diodes D3 and D4 are biased in opposite directions.

If the amplifier 2 fails in this manner, the receiving device 4 detects the occurrence of the failure by not receiving a transmission signal. At the time of this detection, the receiving device 4
3 and R4.

As a result, the diodes D3 and D4, which were previously biased in the reverse direction, are now biased in the forward direction, and a positive power supply voltage is applied to the positive power supply terminal of the amplifier 3, and a negative voltage is applied to the negative power supply terminal of the amplifier 3, so that a power supply current flows. Amplifier 3
transition from the suspended state to the active state. In addition, amplifier 2
In this case, the diodes D1 and D2 are biased in the opposite direction, and the power supply current no longer flows.

As a result, the transmission signal is amplified by the amplifier 3 and sent to the vibrator blade circuit (Tl and R1) and the signal cables L9 and L.
It is transmitted to the receiving device 4 via IO.

Note that even when a short-circuit abnormality occurs in the amplifier 2, the operating amplifier is switched to the amplifier 3 in the same manner as described above.

Therefore, according to the embodiment described above, a rectifying element is inserted in a predetermined direction on the power supply line for each of the duplicated amplifiers, and only one of the amplifiers is selectively put into operation depending on the polarity of the power supply voltage. Therefore, even if an external factor that causes a failure of the amplifier 2 in the operating state occurs, it is possible to avoid failure of the other amplifier 3, and the other amplifier 3 continues to transmit data. operation, and reliability can be further increased.

Further, since the output signals of the two amplifiers are transformer-coupled and output to a pair of signal cables, the number of signal cables can be reduced compared to the conventional method, and installation work can be made easier.

Incidentally, in the conventional device shown in FIG. 2, it may be possible to reduce the number of signal cables by providing a transformer coupling configuration in the signal relay device, but in the case of the conventional device, the amplifier 2
Since amplifiers 2 and 3 are in operation at the same time and the transmission signals are applied to the transformer at the same time, it is necessary that these transmission signals be in phase. However, although amplifiers 2 and 3 are intended to have the same configuration, in reality Because they cannot be configured to be exactly the same, and their characteristics change depending on the surrounding environmental conditions, the transmission signal supplied to the transformer coupling may be in phase, and the waveform of the transmission signal may become dull. It was becoming difficult to achieve the original relay function. According to this embodiment, amplifiers 2 and 3 are alternatively activated, so that such disadvantages do not occur even with transformer coupling.

Further, according to the above embodiment, since the number of input signal cables and the number of output signal cables of the signal relay device 1 are equal, a plurality of signal relay devices are connected between the transmitting device and the receiving device. Easy to insert.

In the above-described embodiment, the outputs of the duplicated amplifiers are combined by a transformer and outputted to the receiving device 4, but other coupling configurations may be used.

Further, in the above-described embodiment, an amplifier is used as the relay circuit, but a circuit other than the amplification function, such as a filter circuit or a waveform shaping circuit, may be used.

Further, the signal cable may be an electrical cable as in the above-described embodiment, or may be an optical fiber cable having a light receiving element and a light emitting element at each input terminal and output terminal.

Furthermore, in the above-described embodiment, the rectifying element inserted to selectively operate the relay circuit is a diode, but other rectifying elements such as a diode etc. It can also be applied.

Further, in the above-described embodiments, the power supply voltages are positive voltages and negative voltages, but they may be positive voltages and ground voltages.

[Effects of the Invention] As described above, according to the first aspect of the present invention, a rectifying element is placed on each power supply line of the relay circuits having the same configuration that are duplicated in the signal relay device. Since the relay circuits are inserted so that they are biased in different conduction directions and operate selectively, circuit failures due to abnormal voltages that enter from the outside via the power cable will occur only on one side, and will not occur on the other side. It is possible to prevent failures in the relay circuits, and also to prevent the entire signal relay device from becoming inoperable due to a short-circuit abnormality in one of the relay circuits. Furthermore, since the relay circuit on the standby side is operated selectively, it is not in relay operation while it is on standby, so the life of the relay circuit can be extended accordingly.

Moreover, according to the second aspect of the present invention, in addition to this, the number of signal cables can be reduced, the installation work can be facilitated, and the entire system can be made inexpensive.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a signal relay device according to the present invention, and FIG. 2 is a block diagram showing a conventional signal relay device. 2.3...Amplifier, D1-D4...Diode, T
R...Transformer, R1...Resistor, R3, R4...
Power cable, R9, LIO...signal cable.

Claims (1)

[Claims] (1) In a signal relay device that includes first and second relay circuits of the same configuration that perform predetermined signal processing on input signals, and that sends an output signal from one relay circuit to a destination device, from the outside. A rectifying element is placed on the power supply line branched from the power cable to the first relay circuit so that the rectifying element is biased in the forward direction with respect to the first power supply voltage, and The rectifying element is inserted so as to be biased in the opposite direction with respect to a second supply voltage obtained by inverting the first supply voltage, and is connected to the second relay circuit branched from the power cable. Another rectifying element is placed on the power supply line such that the rectifying element is biased in the opposite direction with respect to the first supply voltage, and the rectifying element is biased in the opposite direction with respect to the second supply voltage. interposed so as to be biased in a forward direction, and bring the second relay circuit into a rest state with respect to the first supply power voltage at which the first relay circuit is in an operating state;
A signal relay device characterized in that the first relay circuit is brought into a rest state with respect to the second power supply voltage at which the second relay circuit is in an operating state. (2) The output signal from the first relay circuit and the output signal from the second relay circuit are output to a pair of output cables via a single signal coupling circuit. A signal relay device according to claim 1.