JPS6231532B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides low noise band
The present invention relates to a phase pulse signal generation circuit suitable for generating a phase pulse signal on the AC voltage waveform of a leased line or on the AC voltage waveform of a dedicated line.

FIG. 1 shows a basic circuit for transmitting a phase pulse signal to a power distribution line. A capacitor 2 and an electronic switch 3 are connected in series between the AC distribution lines 1 and 1'. When the electronic switch 3 is closed in the currently determined phase, a charging current suddenly flows into the capacitor 2, instantaneously shorting the AC distribution line.
Since the charging current changes in a very short period of time, a phase pulse signal is generated on the voltage waveform of the AC distribution line.

If you want to transmit in the low-noise part of the commercial frequency voltage waveform of the AC distribution line, that is, in the low noise band 5 of the commercial frequency voltage wave 4 in Figure 2, the basic circuit shown in Figure 1 has a sufficient level. Since it is not possible to generate a phase pulse signal of 1, a phase pulse signal generating circuit shown in FIG. 3 has conventionally been used. 6 is a diode, 7 is an injection capacitor, 8 is a capacitor, 9 is a discharge resistor for discharging the charge stored in the capacitor 8, 10 is an inductance, 11 is a capacitor, 12 is a thyristor or other electronic switch, 13 is a thyristor 1
This is the gate input terminal of No. 2. The diode 6, the inductance 10, and the capacitor 11 have high impedance to high frequencies, and constitute a power supply circuit that always applies a high voltage to the series circuit of the capacitor 8 and the thyristor 12. The capacitor 11 is charged to the illustrated polarity via the diode 6 and the inductance 10 at a phase when the commercial frequency voltage of the AC distribution line has a relatively high instantaneous value. Therefore, since the potential of the capacitor 11 is applied to the point a through the inductance 10, the potential at the point a is always maintained at a constant high potential regardless of the phase of the commercial frequency voltage. In this state, when a trigger signal is applied to the gate input terminal 13 of the thyristor 12 at a predetermined phase point, for example, in the low noise band 5 on the commercial frequency voltage wave 4, the thyristor 12 becomes conductive. , a rapid charging current flows through the capacitor 8, and the potential at point a drops instantaneously. At this time, the electric charge charged in the capacitor 11 is prevented from discharging into the series circuit of the capacitor 8 and the thyristor 12 due to the inductance 10, and the potential of the capacitor 11 remains unchanged. This a
The potential change at the point is transmitted to the AC distribution lines 1, 1' through the injection capacitor 7, generating a phase pulse signal 14 in the low noise band 5 on the commercial frequency voltage wave 4, as shown in FIG. I can do it.

However, recently, with the advent of terminal encoder systems, it has become necessary to generate a phase pulse signal consisting of a plurality of phase pulses in the low noise band 5 of the commercial frequency voltage wave 4. The circuit of FIG. 3 is sufficient to transmit one phase pulse in the low noise band 5 of the commercial frequency voltage wave 4, but in order to transmit multiple phase pulses, the discharge of the capacitor 7 must be extremely short. It must be done continuously at intervals. For this purpose, the value of the inductance 10 must be made small so that the capacitor 7 can be charged quickly after completion of discharging. However, if the value of inductance 10 is reduced, capacitor 1
1, the discharge becomes larger and it becomes impossible to maintain the point a at a constant potential. It is extremely difficult to set the value of the inductance 10 so as to satisfy these two conflicting objectives and also to ensure stable operation.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a phase pulse signal generating circuit with high transmission efficiency, which can generate a plurality of stable phase pulses at short intervals.

To achieve this object, the present invention provides a charging circuit comprising a diode and a first capacitor connected in series between the lines of a line to which an alternating current voltage is applied, and a charging circuit connected in series between the lines. an injection circuit comprising a second capacitor and a first electronic switch; a connection point between the diode and the first capacitor in the charging circuit; and a connection point between the second capacitor and the first electronic switch in the injection circuit; and a second electronic switch connected between the two electronic switches, and the on/off timing of both electronic switches is determined so that the second electronic switch is turned off while the first electronic switch is on. .

Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

FIG. 4 shows a phase pulse signal generating circuit according to an embodiment of the present invention. First, a diode 15 and a first capacitor 16 are connected in series between the distribution lines 1 and 1' to form a charging circuit 17.
1', a second capacitor 18, an inductance 19 and a first electronic switch 20 are connected in series to form an injection circuit 21, and a diode 1'.
A second electronic switch 22 and a resistor 23 are inserted between the connection point between the inductor 5 and the capacitor 16 and the connection point between the inductance 19 and the electronic switch 20. 24 and 25 are gate input terminals of electronic switches 20 and 22; 26 is electronic switch 20;
This is a diode for reverse breakdown voltage. The on/off timings of both electronic switches 20 and 22 are determined so that electronic switch 22 is off while electronic switch 20 is on, as shown in FIG.

First, the distribution line voltage is rectified by the diode 15, and the capacitor 16 is charged by this rectified voltage and maintained at a constant voltage. In this state, at time T ₀ in FIG. 5, the electronic switch 20 is off and the electronic switch 22 is on, so the capacitor 18 is charged by the charge on the capacitor 16 through the resistor 23, the electronic switch 22, and the inductance 19. Ru. Next, at time T ₁ ,
The electronic switch 20 is turned on, and the electronic switch 2
2 is turned off, the charge on the capacitor 18 is discharged through the inductance 19 and the electronic switch 20. In this case, since the electronic switch 222 is off, the charge on the capacitor 16 is transferred to the resistor 222.
There is no discharge through the electronic switch 20, and the potential of the capacitor 16 is not affected at all. This discharge produces a dip portion 28 of the phase pulse 27 shown in FIG. 6 on the commercial frequency voltage wave 4. If there is no inductance 19, a spike wave 29 as shown by the dotted line will be generated, but in reality, due to the presence of the inductance 19, the waveform will be a vibration waveform due to gentle resonance. Then the time
At _T2 , the electronic switch 20 is turned off. Even when the electronic switch 20 is turned off at time _T2 , an over portion 30 shown in FIG. 6 occurs due to the electromotive force in the opposite direction generated in the inductance 19, and thereafter attenuates in about half a cycle. When the timing is set so that the electronic switch 22 is turned on at time T ₃ in synchronization with the rise of the over portion 30, the capacitor 1 is turned on by turning on the electronic switch 22.
6 to capacitor 18 via inductance 19
However, this charging waveform is over portion 3.
Waveform 3 superimposed on 0 and shown as a dotted line in FIG.
It becomes 1. If there is no inductance 19,
Although this becomes a spike wave 32, it becomes a gentle waveform 31 due to the presence of the inductance 19.

Since the electronic switch 22 provided between the charging circuit 17 and the injection circuit 21 is turned off while the electronic switch 20 is on, the charging voltage of the capacitor 16 does not drop. Therefore, when the electronic switch 22 is turned on after the electronic switch 20 is turned off, the capacitor 18 is rapidly charged from the capacitor 16, reducing the time required to prepare for the next transmission. Therefore, it becomes extremely easy to inject a plurality of phase pulses 27 into the low noise band 5 of the commercial frequency voltage wave 4.

Furthermore, since the capacitor 16 will not be discharged during the transmission operation by turning off the electronic switch 22,
The charging voltage of the capacitor 16 is always kept constant,
Therefore, even if the phase pulses 27 are generated at short intervals, the capacitor 18 is always charged to the same level, that is, the level of the phase pulses 27 is always the same level, and the transmission efficiency is improved. Note that since the capacitance of the capacitor 18 is considerably smaller than that of the capacitor 16, even if the capacitor 18 is charged from the capacitor 16, the charging voltage of the capacitor 16 will hardly decrease.

In the embodiment of FIG. 4, resistor 23 is not absolutely necessary. Also, the inductance 19 can be omitted if it can be replaced by an inductance on the distribution lines 1, 1'. electronic switch 2
As 0 and 22, transistors, thyristors, etc. can be used.

The present invention allows phase pulse signals to be transmitted not only in the low noise band 5 but also in other phase bands. Further, the present invention can be used not only for AC distribution lines but also for dedicated lines to which AC voltage is applied.

As explained above, according to the present invention, the charging circuit and the injection circuit are separated by the second electronic switch, and while the electronic switch of the injection circuit is on, the second electronic switch is switched on.
Since the electronic switch is turned off, multiple stable phase pulses can be generated at short intervals, improving transmission efficiency.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing the basic circuit of a conventional phase pulse signal transmission circuit, Figure 2 is a waveform diagram showing a state in which a phase pulse signal is transmitted on a commercial frequency voltage wave, and Figure 3 is a circuit diagram of a conventional phase pulse signal transmission circuit. A circuit diagram of a signal transmission circuit, FIG. 4 is a circuit diagram showing an embodiment of the present invention,
FIG. 5 is a time chart showing the operation timing of an electronic switch according to an embodiment of the present invention, and FIG. 6 is a waveform diagram of a phase pulse transmitted according to an embodiment of the present invention. 1, 1'... Distribution line, 15... Diode, 1
6...First capacitor, 17...Charging circuit, 1
8... Second capacitor, 20... First electronic switch, 21... Injection circuit, 22... Second electronic switch, 27... Phase pulse.

Claims (1)

[Claims] 1. A charging circuit consisting of a diode and a first capacitor connected in series between the lines of a line to which an alternating current voltage is applied, a second capacitor connected in series between the lines, and a first electronic switch. and a second electronic switch connected between a connection point between the diode and the first capacitor in the charging circuit and a connection point between the second capacitor and the first electronic switch in the injection circuit. A phase pulse signal generating circuit comprising: a phase pulse signal generating circuit having timings for turning on and off both electronic switches such that the second electronic switch is turned off while the first electronic switch is on.