JPS6155081B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for heating and fusion splicing optical fibers using gas discharge, and more particularly to an optical fiber fusion splicing apparatus that can reduce the no-load output voltage.

Conventional optical fiber fusion splicing equipment (hereinafter referred to as a splicer) uses a detector to detect the output arc current by increasing the output voltage at no-load to a high voltage of 10 kV or more, shortening the time from spark discharge to arc discharge. From the beginning, a control circuit controlled this current to a value suitable for fusion splicing optical fibers. However, with this, the output voltage at no load is
Since the voltage is 10kV or more, there are disadvantages such as the need for a large high-voltage transformer and the need to increase the dielectric strength.

SUMMARY OF THE INVENTION An object of the present invention is to provide a splicer which can reduce the output voltage under no load and which can perform fusion splicing of high-quality optical fibers in order to eliminate the above-mentioned drawbacks.

In order to achieve the above object, the present invention makes it possible to reduce the output voltage during no-load, to narrow down the optical fiber to a value suitable for fusion splicing, for example, when starting the arc from spark discharge to arc discharge. , focused on making the arc start unstable, and set a current value sufficient for short arc start until the arc is completely started, and after the arc becomes stable, the optical fiber is fused using a current control circuit. It is characterized by controlling the arc current to a value suitable for the connection.

Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 is a block diagram of the splicer circuit according to the embodiment of the present invention, Fig. 2 is a time chart showing the operation of each part, A shows the state of change in the output current, B shows the operation of relay 7, and C shows the operation of relay 3. Operation, D shows the operation of the start switch 11. FIG. 3 shows the operating characteristics of the splicer output.

In the figure, 1 is a commercial power supply, 2 and 10 are rectifiers, and 3 and 7
is a relay, 4 is a high frequency oscillator, 5 is a high voltage transformer, 6 is a detector, 8 is a current control circuit, 9 is a power transformer, 11 is a start switch, 12 is a timer, 13 is a delay timer, and R is a stabilizing resistor. .

To obtain high voltage output, the AC voltage from the commercial power supply 1 is rectified into DC by the rectifier 2, the high frequency is outputted by the high frequency oscillator 4 via the relay 3, and the high voltage of 4000v to 6000v is generated by the high voltage transformer 5. An arc is generated which is outputted through a stabilizing resistor R and used for fusion splicing of optical fibers. On the other hand, the arc current is detected by the detector 6, and the current control circuit 8 calculates the difference between the arc current and a current value suitable for fusion splicing of optical fibers, and sends feedback to the high frequency oscillator 4, so that the arc current becomes light. The current value is set to be suitable for fiber fusion splicing.

On the other hand, regarding time control, an AC voltage from a commercial power supply 1 is stepped down by a power transformer 9 and converted to DC by a rectifier 10 for driving a start switch 11, a timer 12, and a delay timer 13. When the start switch 11 is turned on, the relay 3 operates as shown in FIG. 2, a high voltage is generated at the output, and spark discharge begins. At this moment, the delay timer 13 has not yet activated the relay 7, so the arc starts at point MP1, the intersection of the characteristics A and B in Figure 3 (output current 40 mA). In FIG. 3, A shows the characteristics of the discharge electrode, B shows the operating characteristics of the output when the current control circuit 8 is not operating, and C shows the operating characteristics of the output when the current control circuit 8 is operating. B and C have a drooping characteristic due to the stabilizing resistor R. The time it takes for the relay 3 to operate and the arc to stably start is several milliseconds when the output voltage is 4000v to 6000v as in this example, so the setting time for the delay timer 13 is a little longer, for example, about 5 milliseconds. Keep it. (However, the operating time of relay 3 is not included in this figure.) Therefore, as shown in Fig. 2, relay 7 operates 5 milliseconds after the start switch 11 is turned on.
The current control circuit 8 starts operating. Current control circuit 8
Through this operation, the output current is controlled to a value of 25 mA, which is the most suitable value for fusion splicing of optical fibers, and the operating point becomes MP2. Next, apply the above arc current for the most suitable time (1 to 10
Since the timer 12 is set to a time period of 2 seconds), when this time elapses, the relays 3 and 7 are disconnected, arc discharge and arc current control are completed, and the optical fibers are completely fused and spliced. Although an arc with a relatively large power is generated for 5 milliseconds when the arc is started, there is no problem in actual use such as excessive melting of the optical fiber, and this example reduces the no-load output voltage of the splicer to Even if the voltage is lowered to 6kV, the optical fibers will be completely fused and spliced.

FIG. 4 is a block diagram of a splicer circuit according to another embodiment of the present invention, and FIG. 5 shows operating characteristics of the splicer output of FIG. 4.

Components in the figure that have the same functions as those in FIG. 1 are indicated by the same symbols. 13' is a delay timer, 14 and 15 are current control circuits, A in FIG. 5 is the same characteristic of the discharge electrode as A in FIG. The operating characteristics of the output are shown below.

The difference between FIG. 4 and FIG. 1 is that a current control circuit 14 is provided to set an arc current value that facilitates arc starting. That is, start switch 1
When 1 is input, relay 3 operates and outputs 4000v~
A voltage of 6000v is generated and spark discharge begins. From this moment, the current control circuit 14, which is set to a current value of 40 mA in this example, at which arc starting can be easily performed, functions, and the arc starts at MP1' in FIG. Next, as in the example shown in Fig. 1, it takes several milliseconds for a stable arc discharge to occur, so the current control circuit 15 starts its function by the delay timer 13', which is set to a slightly longer time of about 5 milliseconds. do. As a result, the operating point of the arc immediately shifts to a current setting value suitable for fusion splicing of optical fibers, 25 mA in this example, and the arc continues. Point MP2' in FIG. 5 is this operating point. Thereafter, when the discharge time (1 to 10 seconds) set in the timer 12 has passed, the relay 3 is turned off and the discharge ends. In this embodiment, the current control circuit 14,
15 has a drooping characteristic, the output operating characteristics are as shown in FIG. 5 D and E.

The current control circuit 8 in FIG. 1 and the current control circuit 15 in FIG. The control operation may be started by detecting this by utilizing the drop to v.

As explained in detail above, according to the present invention, the no-load output voltage can be lowered, so the high-voltage transformer can be made smaller, the dielectric strength structure can be simplified, and the fusion splicing of high-quality optical fibers becomes possible. There is.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a splicer circuit according to an embodiment of the present invention, Fig. 2 is a time chart showing the operation of each part, Fig. 3 is an operational characteristic of the splicer output in the case of Fig. 1, and Fig. 4 is a diagram of the present invention. FIG. 5, a block diagram of a splicer circuit according to another embodiment of the invention, shows the operating characteristics of the splicer output in the case of FIG. In the figure, 1 is a commercial power supply, 2 and 10 are rectifiers, and 3 and 7
is a relay, 4 is a high frequency oscillator, 5 is a high voltage transformer, 6 is a detector, 8, 14, 15 are current control circuits, 9 is a power transformer, 11 is a start switch, 12 is a timer, 13, 13' are delay timers, R is a stabilizing resistance.

Claims (1)

[Claims] 1. In a device for heating and fusion splicing optical fibers by gas discharge, there is an arc generation section that generates an arc for optical fiber fusion, and an arc current output from the arc generation section is detected and a current suitable for fusion is determined. and a setting section connected to the arc generating section and the arc current controlling section to set the driving time of the arc generating section and the arc current of the arc current controlling section. Optical fiber fusion splicing equipment.