JPH0642645B2 - Induction antenna device - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an improvement of an induction antenna device used in, for example, railways, roads, and tunnels.

[Technical background of the invention and its problems]

Generally, in this type of device, for example, as shown in FIG. 1, the transmission output of a transmitter 1 is fed to a feeder line 2 and a hybrid transformer 3.
It is configured to supply to the guide lines 4a and 4b through the matching device composed of a and the matching transformer 3b, respectively, and thereby to perform transmission. In the figure, 5 is a terminating resistor.

By the way, in this type of device, it is generally necessary to monitor an abnormality such as a disconnection or a ground fault.
As shown in the figure, the induction wires 4a and 4b are connected to the yoke coil 6
A monitoring line 8 for direct current is led to the transmitting device 7 in which the transmitter 1 is installed via a loop, and a loop resistance monitoring circuit 9 and a ground resistance monitoring circuit 10 are connected to the monitoring line 8 to perform abnormality monitoring. ing.

Therefore, it is necessary to draw out the monitoring line 8 for each of the guide lines 4a and 4b, and to provide the loop resistance monitoring circuit 9 and the ground resistance monitoring circuit 10, respectively, which leads to an increase in the size of the device. Further, in the above-mentioned conventional configuration, the guide wire 4
Only the abnormalities a and 4b can be monitored, and the abnormalities including the feeder line 2 and the transmitter 1 cannot be monitored.

[Object of the Invention]

The present invention provides an inductive antenna device having excellent monitoring performance capable of simplifying the configurations of the loop resistance monitoring circuit and the ground resistance monitoring circuit and performing abnormal monitoring of all the constituent elements including a power feeding path such as a power feeding line. The purpose is to do.

[Outline of Invention]

In order to achieve the above-mentioned object, the present invention connects a power supply line and an induction wire in an AC manner through a matching unit, and transmits the transmission output of a transmitter to the dielectric line through the power supply line and the matching unit, respectively. In the inductive antenna device to be supplied, a choke coil is inserted between the primary side winding and the secondary side winding of the matching unit, and the feeder line and the induction line are connected to each other by direct current so that the transmitter The power supply line and the induction line are connected in series to form a direct current loop, and a loop resistance monitoring circuit and a ground resistance monitoring circuit are respectively inserted in the direct current loop.

Example of Invention

FIG. 2 is a circuit configuration diagram of the induction antenna device according to the embodiment of the present invention. In the figure, the same parts as those in FIG.

The hybrid transformer 31 and the matching transformers 32 and 33 of the matching unit 30 have their primary side and secondary side short-circuited via a high-frequency chain coil 34, respectively. A DC blocking capacitor 35 is inserted in each of the primary winding and the secondary winding of each of the transformers 31, 32 and 33. Then, the power supply line 2 and each of the guide lines 4a, 4
b is connected in a direct current, and as a result, a direct current loop is formed in which the transmitter 1, the power supply line 2, the terminating resistor 5, the loop resistance monitoring circuit 9, the high-frequency chain coil 71, and the induction lines 4a and 4b are connected in series. To be done. Loop resistance monitoring circuit 9
Is a DC blocking capacitor 72 in the transmitter 70.
Are connected to both ends of each through a high-frequency chain yoke coil 71. Further, the ground resistance monitoring circuit 10 is connected between the other end of the high-frequency chain coil 71 whose one end is connected to the power supply line 2 and the ground end. Reference numeral 72 is a capacitor that passes only the high frequency transmission output.

With such a configuration, the transmission output of the transmitter 1 is supplied to the respective induction lines 4a and 4b through the power supply line 2, the hybrid transformer 31, and the matching transformers 32 and 33 without any change from the conventional case (FIG. 1). Then, the transmission is performed.

On the other hand, the DC monitoring current of the loop resistance monitoring circuit 9 is
-Hyoke coil 34 of the hybrid transformer-Choke coil 34 of the matching transformer 32-Induction line 4a-Choke coil 34 of the matching transformer 32-Choke coil 34 of matching transformer 33-Induction line 4b-Choke coil 34 of matching transformer 33-Choke coil 34 of hybrid transformer 31- The power supply line 2 flows through the path of the loop resistance monitoring circuit 9, and the disconnection is monitored by this. Further, the DC monitoring current of the ground resistance monitoring circuit 10 also flows through the same route as the loop resistance monitoring current and finally flows to the ground end, whereby the ground resistance is monitored, that is, the ground fault is monitored.

In this way, according to this embodiment, by forming a DC loop in which all the components including the power supply line are serially connected,
It is possible to monitor disconnection and ground fault for all components at once. Therefore, reliable monitoring can be performed without overlooking the abnormality. Further, since the power supply line 2 is used as a monitoring line, it is not necessary to provide a separate monitoring line, and it is also necessary to provide a separate loop resistance monitoring circuit 9 and ground resistance monitoring circuit 10 for each induction line 4a, 4b. Since only one set of the monitoring circuits 9 and 10 is required, the configuration of the device can be remarkably simplified and downsized as compared with the conventional one. As a result, the cost of the device can be reduced.

The present invention is not limited to the above embodiment,
For example, the insertion position of each chain yoke coil and the insertion position of the loop resistance monitoring circuit and the ground resistance monitoring circuit can be variously modified and implemented without departing from the scope of the present invention.
For example, it can be inserted into the guide wires 4a and 4b. In addition, a switching circuit for switching the path of the DC loop from the matching transformer 32 to the hybrid transformer 31 is provided between the matching transformers 32 and 33, and this switching circuit is remotely operated and switched on the transmitting device side, so that each induction line 4a, 4b The abnormal position may be confirmed. By doing this, when an abnormality occurs, the occurrence position of the abnormality can be set to each guide wire 4
It can be confirmed for each a and 4b, and the time required for restoration can be greatly shortened.

[Effects of the Invention] As described in detail above, according to the present invention, a choke coil is inserted between the primary side winding and the secondary side winding of a matching unit to connect the power supply line and the induction line to direct current. By connecting to form a DC loop in which the transmitter and the induction wire of the power supply line are connected in series, and by inserting a loop resistance monitoring circuit and a ground resistance monitoring circuit into this DC loop, respectively. The loop resistance monitoring circuit and the ground resistance monitoring circuit can be simplified in configuration, the transmitter can be downsized, and all the constituent elements including the power feeding path such as the power feeding line can be monitored for abnormalities. An inductive antenna device with excellent performance can be provided.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of a conventional induction antenna device,
FIG. 2 is a circuit configuration diagram of the induction antenna device according to the embodiment of the present invention. 1 ... Transmitter, 2 ... Feed line, 4a, 4b ... Induction line,
5 ... Termination resistance, 9 ... Loop resistance monitoring circuit, 10 ...
Ground resistance monitoring circuit, 30 ... Matching device, 31 ... Hybrid transformer, 32, 33 ... Matching transformer, 34, 7
1 ... High frequency Chiyoke coil, 35, 72 ... DC blocking capacitor, 70 ... Transmitter.

Claims (1)

[Claims] 1. An inductive antenna device, wherein a power supply line and an induction wire are AC-connected via a matching unit, and a transmission output of a transmitter is supplied to the dielectric line via the power supply line and the matching unit, respectively. By inserting a choke coil between the primary side winding and the secondary side winding of the matching unit and connecting the power supply line and the induction line in a direct current manner, the transmitter, the power supply line and the induction line are connected. Forming a DC loop connected in series, and inserting a loop resistance monitoring circuit and a ground resistance monitoring circuit into the DC loop, respectively.