JP3212835B2 - Discharge control method and apparatus for optical fiber fusion splicer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge control method in an optical fiber fusion splicer and an apparatus used for the method.

[0002]

2. Description of the Related Art In an optical fiber fusion splicer, the amount of heat generated in the aerial discharge for melting the end face of an optical fiber varies depending on the state of air serving as a heating resistor. Therefore, it is necessary to correct the discharge conditions depending on the state of the air in order to obtain the optimal discharge heat generation.

For this reason, a discharge control device as shown in FIG. 4 has conventionally been used. In FIG. 4, 11 is an optical fiber to be fusion-spliced, 13 is a discharge electrode, and 15 is a power supply for discharge. In this apparatus, the discharge power supply 15 is controlled as follows in order to obtain an optimal discharge heat generation amount.

First, various parameters representing the state of air, such as atmospheric pressure, temperature, and humidity, are measured by sensors 17a, 17b, and 17c.
... Next, a correlation coefficient calculator 19 calculates a correlation coefficient between the change in each parameter and the change in the amount of heat generated by discharge. The arithmetic unit 19 incorporates conditional expressions obtained in advance by experiments. Next, the computing unit 2 is calculated from the correlation coefficient and the target value 21.
In step 3, a correction value is obtained, and the correction value is added to the previous discharge condition by the adder 25, and the discharge condition of the discharge power supply 15 is determined so that the next discharge heat generation amount is optimized. Conventionally, control has been performed in such a manner as to optimize the amount of heat generated by discharge.

[0005]

The conventional discharge control employs means for detecting the state of air and correcting the discharge condition based on the detected state. Therefore, a large number of sensors are required to detect the air condition. In addition, since the amount of heat generated by discharge also changes due to deterioration of the electrodes and the attachment of foreign matter to the electrodes, it is not possible to cope with a change in the amount of heat generated by discharge only due to factors other than air.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and apparatus for controlling a discharge of a fusion splicer which does not require a large number of sensors and which can appropriately control the amount of generated heat in response to changes in all parameters affecting the discharge. To provide.

[0007]

According to the present invention, a discharge voltage and a discharge current of a circuit including a discharge electrode and a discharge power supply are detected, and an impedance between the discharge electrodes is calculated from the detected values. , Wherein the subsequent discharge intensity is corrected according to the calculated change in impedance.

[0008]

[Function] Since the effects of all parameters such as air condition and electrode surface condition are integrated in the impedance between the electrodes during discharge, this impedance is obtained, and the target value is corrected by using the impedance. If controlled, it becomes possible to perform appropriate discharge control corresponding to changes in all parameters that affect discharge.

[0009]

FIG. 1 shows an embodiment of the present invention. 11 is an optical fiber, 13 is a discharge electrode, and 15 is a power supply for discharge. This device includes a detector 27 that detects a discharge voltage and a discharge current of a circuit including the discharge electrode 13 and the discharge power supply 15. The values of the discharge voltage and the discharge current detected by the detector 27 are input to an impedance calculator 29, where the impedance between the discharge electrodes is calculated. This impedance is affected by all parameters that affect the discharge, such as the state of the air and the state of the discharge electrode at that time.

Next, a correction value is obtained by the calculator 33 from the calculated impedance and the target value 31 of the discharge intensity, and the correction value is added to the previous discharge condition by the adder 35, so that the next discharge heat generation is optimized. The discharge condition of the discharge power supply 15 is determined so that This makes it possible to perform appropriate discharge control taking into account changes in all parameters that affect discharge.

FIGS. 2 and 3 show a more specific embodiment of the present invention. This device comprises a discharge circuit and a discharge control circuit. Assuming that the impedance between the electrodes during discharge is Z _G and the impedance of the discharge circuit (all impedances other than Z _G ) is Z _S , the discharge circuit can be expressed as shown in the upper part of FIG. The impedance Z _S is a characteristic value of the discharge circuit, and the impedance Z _G is a value that changes depending on the state of air, the surface state of the electrode, and the like. The discharge power supply 15 can change a discharge voltage and a discharge current by a control signal from the outside.

On the other hand, the discharge control circuit has a detector 27 for detecting a voltage waveform v and a current waveform i of the discharge circuit.
The voltage waveform v and the current waveform i detected by the detector 27 are input to A / D converters AD1 and AD2, respectively, where they are digitally encoded. The arithmetic circuit ALU calculates the impedance between the discharge electrodes from the digitally encoded voltage waveform and current waveform, and creates a voltage control signal and a current control signal for controlling the discharge power supply 15 toward the target value 31. Therefore, the following operation is performed in the arithmetic circuit ALU.

Detector 27 attached to discharge circuit
Detects a voltage waveform v and a current waveform i as shown in FIG. Since this waveform is digitally encoded and input to the arithmetic circuit ALU, the peak value is found by sequentially comparing the values. As a result, a maximum value v ₀ of the voltage, a maximum value i ₀ of the current, and a phase delay Δφ of the current with respect to the voltage are obtained.

An effective value V of the voltage and an effective value I of the current are calculated by statistical processing of the voltage waveform v and the current waveform i. From the effective value V of the voltage and the effective value I of the current, the absolute value of the total impedance | Z | (= | Z _S +
Z _G |) is calculated.

[0015]

| Z | = V / I

The absolute value of this impedance | Z |
Then, the resistance component R and the reactance component X of the impedance of the discharge circuit are obtained from the current delay Δφ with respect to the voltage.

[0017]

R = | Z | cos Δφ X = | Z | si
n Δφ

From the resistance component R and the reactance component X of the impedance of the discharge circuit, a resistance component R _G and a reactance component X _G of the impedance between the electrodes during discharge are obtained.

[0019]

[Number 3] _{R G = R-R S X} G = X-X S

[0020] From the resistance component R _G and the reactance component X _G of the impedance between the electrodes during discharge, it obtains the power P _G to be supplied between the electrodes during discharge.

[0021]

| Z _G | = √ (R _G ² + X _G ² )

[0022]

P _G = | Z _G | I ² cos Δφ [or P _G = | Z _G | (V ² / | Z | ² ) cos Δφ]

Power P _G supplied between electrodes during discharge
And the target power P _GO . As a result of the comparison, if they match, no correction command is issued. If the two do not match as a result of the comparison, a correction command for one or both of the current and the voltage is issued. Each effective value is obtained from the target power P _GO by the following calculation. Equation (6) is for correction with current, Equation (7) is for correction with voltage, and Equation (8) is for correction with current and voltage.

[0024]

I ₀ = {P _GO / (| Z _G | cos Δφ)}

[0025]

V ₀ = √ ｛| Z | ² P _GO / (| Z _G | cos
Δφ)｝

[0026]

I ₀ V ₀ = √ ｛| Z | P _GO / (| Z _G | co
s Δφ)｝ The arithmetic circuit ALU creates the voltage control signal and the current control signal as described above. The generated signals are converted into analog signals by D / A converters DA1 and DA2, respectively, and are used as a voltage control signal V _CO and a current control signal _ICO as a discharge power source 1.
5 is input. The discharge power supply 15 is thereby controlled so that the next discharge intensity is appropriate.

[0027]

As described above, according to the present invention, a discharge current and a discharge voltage which are affected by changes in all parameters such as an air state and an electrode surface state are detected, and the impedance between the discharge electrodes is detected therefrom. , And control of the discharge conditions is performed, so that it is possible to faithfully cope with changes in all parameters, and to perform appropriate discharge heat generation control.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a discharge control device according to the present invention.

FIG. 2 is a circuit block diagram showing a more specific embodiment of the present invention.

FIG. 3 is a graph showing a discharge voltage waveform and a discharge current waveform.

FIG. 4 is a schematic configuration diagram showing a conventional discharge control device.

[Explanation of symbols]

11: Optical fiber 13: Discharge electrode 15: Power supply for discharge 27: Detector 29: Impedance calculator 31: Target value 33: Calculator 35: Adder Z _G : Impedance between electrodes during discharge Z _S : Discharge circuit Impedance (all impedances other than Z _G ) AD1, AD2: A / D converter ALU: Arithmetic unit DA1, DA2: D / A converter

Claims (2)

(57) [Claims] 1. A discharge voltage and a discharge current of a circuit including a discharge electrode and a discharge power supply are detected, an impedance between the discharge electrodes is calculated from the detected values, and a subsequent discharge intensity is calculated according to a change in the calculated impedance. A discharge control method for an optical fiber fusion splicer, wherein the correction is performed. A detecting means for detecting a discharge voltage and a discharge current of a circuit including a discharge electrode and a power supply for discharge; a calculating means for calculating an impedance between the discharge electrodes from the detected values; A discharge control device for an optical fiber fusion splicer, comprising: a correction unit that corrects a discharge intensity by using a control unit.