JP2765730B2 - Failure detection device for transmitter for track circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial application field >> The present invention relates to a failure detection device for a transmitter used in a track circuit.

<< Prior Art >> FIG. 3 is a schematic configuration diagram of a conventional track circuit. In track 1, each block section (hereinafter referred to as section) 1T formed by dividing the track at a predetermined interval is shown. , 2T, 3T,..., A transmitter 2 and a receiver 3 are provided.

In this track circuit, when train a advances from section 1T in the direction of 2T and enters section 2T, track 1 of section 2T is short-circuited by axle W of train a, and signal transmission to receiver 3 is interrupted. You.

Therefore, depending on the reception state of the receiver 3, this section 2T
Of the train a from the section 2T and the advance of the train a from the section 2T can be detected.

The transmitter 2 includes a constant current type using a constant current type amplifier circuit and a constant voltage type using a constant voltage type amplifier circuit.

In the case of the constant current type, the failure detection of the transmitter 2 is performed by monitoring whether or not the signal current supplied to the track 1 is maintained at a predetermined value. In the case of the type, it is performed by monitoring whether the signal voltage supplied to the track 1 is maintained at a predetermined value.

<< Problems to be Solved by the Invention >> By the way, the above-mentioned conventional transmitters, both of a constant current type and a constant voltage type, are provided for improving voltage or current characteristics for the purpose of improving train detection characteristics. There is a disadvantage that current efficiency is reduced by the resistance.

Therefore, the present applicant has previously filed a patent application as a transmitter in which such a defect is improved.

The transmitter according to the prior application detects the output voltage and the output current of the amplifier circuit, adds the detection signals, and
In addition, feedback control is performed so that the added signal is constant, and the output impedance of the amplifier circuit is maintained at a constant value. Therefore, since there is no resistance for improving characteristics, there is an advantage that high power efficiency can be obtained and train detection can be performed with high accuracy.

However, unlike the conventional transmitter, the transmitter according to the prior application has an inconvenience that the output signal is not a constant current or a constant voltage, so that it is impossible to detect a transmitter failure by monitoring these signals.

An object of the present invention is to provide a failure detection device for a track circuit transmitter, which is capable of accurately detecting a failure of a transmitter according to the prior application.

<< Means for Solving the Problems >> In order to achieve the above object, the present invention detects an output voltage and an output current of an amplifier circuit that amplifies an oscillation output from an oscillation circuit, adds the detection signals, and Feedback control is performed so that the addition signal becomes constant,
A failure detection device for a track circuit transmitter configured to maintain an output impedance of the amplifier circuit at a constant value, comprising: a voltage detection circuit that detects a voltage of an output signal from the transmitter; and an output from the transmitter. A current detection circuit for detecting the current of the signal; an addition circuit for adding the two detected values; a comparison between the addition output value of the addition circuit and a reference signal; And a comparing circuit for stopping the output when the transmitter is out of order when out of the range.

<< Operation >> In the above configuration, the voltage detection circuit detects the output voltage of the output signal of the transmitter, and the signal current detection circuit detects the output current of the output signal of the transmitter.

The adding circuit adds the two detected values, and sends the added value to the comparing circuit. The comparison circuit compares the added value with a predetermined reference value. If the added value is within the reference value, a normal signal is output from the transmitter. If the added value is outside the reference value, the output is stopped as a transmitter failure.

<< Example >> Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing one embodiment of the device of the present invention.

The transmitter 10 has been proposed in the prior application and includes an oscillation circuit 10a, an amplification circuit 10b, and a control circuit 10c. Here, the detailed description is left to the earlier application, and the outline is described.

In the transmitter 10, the signal from the oscillation circuit 10a is amplified by the amplification circuit 10b. The control circuit 10c detects the output current Vi and the output voltage Vv of the output signal from the amplifier circuit 10b, and controls the gain of the amplifier circuit 10b so that the sum of the two detected values (Vv + Vi = Vo) is always constant. Is adjusted.
Therefore, the transmitter 10 can always have a constant output impedance Zo as shown in FIG.

The output signal of the transmitter 10 is sent to the section 1T via the voltage detection circuit 21 and the current detection circuit 22 of the failure detection device 20.
In this figure, an example in which transmission is performed to the section 1T is shown, but similar transmitters are provided in the other sections 2T, 3T.

Both detection circuits 21 and 22 are both are formed from the transformer, in these voltage detecting circuit 21 to the secondary winding n ₁ of the transformer T ₁ and the voltage detection winding, while the transformer T ₂ in the current detection circuit 22 the secondary winding n ₂ is set to the current detection winding of.

Secondary windings n ₁ and the detection voltage output from the n ₂ Vv and detected current Vi each known bandpass filters 23a, 23b and the rectifier circuit 24a, are prepared are sent to 24b. Thereafter, these two detection values are sent to a well-known addition circuit 25 and added,
The output signal (addition value) of the addition circuit 25 is sent to a comparison circuit 26 comprising a well-known window comparator and compared with a reference signal.

As the value of the reference signal, upper and lower limits determined using the constant voltage value Vo shown in FIG. 2 as a center are used.

Next, the operation of the above-described configuration of the apparatus of this embodiment will be described.

Now, it is assumed that the output signal is transmitted from the transmitter 10 to the orbit 1 in the section 1T. As shown in FIG. 2, this output signal is controlled and output so that the sum of the output voltage Vv and the output current Vi becomes constant even if the load impedance fluctuates.

In the voltage detection circuit 21, the output voltage Vv of the signal 10 via the second winding n ₁ of the transformer T ₁ is detected, whereas the current detection circuit
In 22 output current Vi signals 10 via the secondary winding n ₂ of the transformer T ₂ is detected.

The detected output voltage Vv and output current Vi are prepared by bandpass filters 23a and 23b and rectifiers 24a and 24b, respectively, and then sent to the addition circuit 25. Since the value added by the adder circuit 25 is rectified by the rectifiers 24a and 24b, even if the load impedance changes to L-type or C-type due to train entry, accurate values are obtained without being affected by the phase difference. An addition result is obtained.

The addition signal (addition value) from the addition circuit 25 is compared with a reference signal by a window comparator (comparison circuit) 26. That is, when the added signal exceeds an upper limit value set around the normal level (constant voltage value) Vo of the transmitter 10 shown in FIG. 2, or a lower limit value limited around the level Vo. When the difference is less than the threshold, the window comparator 26 restores the relay CHR for notifying the transmitter 10 of an abnormality (failure).

In this embodiment, the transmitter 10 includes an amplifying circuit 10b.
The output voltage Vv and the output current Vi are detected, the detection signals are added, and the control circuit 10c controls the amplification circuit 10b so that the added signal becomes constant. For this reason, since there is no resistance for improving characteristics as in the related art, a transmitter with high power efficiency can be obtained, and train detection can be performed with high accuracy.

The failure detection device 20 detects the output signal from the transmitter 10 using a voltage detection circuit 21 to detect the output voltage Vv, and the current detection circuit 22 to detect the output current Vi. After being adjusted by the rectifiers 23a and 23b and the rectifiers 24a and 24b, they are added by an adding circuit 25, and the added signal is compared by a window comparator 26 with a reference signal having upper and lower limits. When the comparison results in a mismatch, the output to the relay CHR is stopped.

Therefore, when the output from the window comparator 26 stops, it means that there is an abnormality in the output of the transmitter 10, whereby a failure of the transmitter 10 is detected. Moreover,
Since the two detection signals to be added are adjusted by the rectifiers 24a and 24b, the added value can be made accurate.

As described above, the apparatus according to the present embodiment includes the transmitter 10 itself,
Since the power efficiency is high, the train detection accuracy is good, and the failure of the transmitter 10 can be detected with high accuracy, a track circuit transmitter excellent in economy and fail-safe can be obtained.

<< Effect of the Invention >> In the device of the present invention, the failure detection device detects the output signal from the transmitter using a voltage detection circuit to detect the output voltage, and the current detection circuit detects the output current Vi, and detects the detected voltage and current. Since the addition signal is added by the addition circuit and the addition signal is compared with the reference signal by the comparison circuit, the state of the transmitter can be monitored by the output state from the comparison circuit,
The failure of the transmitter can be accurately detected.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an embodiment of the apparatus of the present invention, and FIG.
The figure is a characteristic diagram of the transmitter, and FIG. 3 is a schematic configuration diagram of a general track circuit. DESCRIPTION OF SYMBOLS 1 ... Orbit, 10 ... Transmitter, 10a ... Oscillation circuit, 10b ... Amplification circuit, 10c ... Control circuit, 20 ... Failure detection device, 21 ... Voltage detection circuit, 22 ... Current detection circuit, 23a, 23b ... Band filter circuit, 24a, 24b ... rectifier circuit, 26 ... window comparator (comparison circuit).

Claims (1)

(57) [Claims] An output circuit for detecting an output voltage and an output current of an amplifier circuit for amplifying an oscillation output from the oscillation circuit, adding the detection signals, and performing feedback control so that the added signal is constant; A failure detection device for a track circuit transmitter configured to maintain an output impedance of an amplifier circuit at a constant value, comprising: a voltage detection circuit that detects a voltage of an output signal from the transmitter; and an output signal from the transmitter. A current detection circuit for detecting the current of the above, an addition circuit for adding the two detected values, and comparing an addition output value of the addition circuit with a reference signal, an output value of the addition circuit being a reference signal value. A failure detection device for a track circuit transmitter, comprising: a comparison circuit that stops output when the transmission is out of range.