JPS5910164A - Firing device for thyristor - Google Patents

Abstract

PURPOSE:To enable to readily correct the irregularity of characteristics of the parts which form an optical firing system by providing a plurality of groups of light emitting elements connected in series with each other, and connecting the groups in parallel with each other, thereby enabling to adjust the drive current between the group. CONSTITUTION:Light emitting diodes 2-1-1-2-1-3 form a group A, and a current regulating variable resistor 7-1 is connected in series with the diodes. Similarly, light emitting diodes 2-2-1-2-2-3 form a group B, and a variable resistor 7-2 is connected in series with the diodes. The diodes of the group A emit light outputs to phototransistors 4-1-1-4-1-3 through light guides 3-1-1-3-1-3, and the diodes 4-2-1-4-2-3 of the group B emit light outputs to phototransistors 4-2-1-4-2-3. The absolute value of the light output can be regulated by variable resistors 7-1, 7-2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an ignition device that simultaneously ignites a large number of cyrisks by optically transmitting a pulse signal.

[Background of the invention]

In large power conversion controllers such as DC power transmission, when the voltage and current of the thyristors used as power conversion control elements are smaller than the desired output, multiple thyristors are connected in series and parallel, and each thyristor is turned on at the same time. Make an arc. In this case, for the ignition of each thyristor, the ignition signal obtained from a common signal source is distributed to each thyristor, but it is necessary to provide sufficient insulation between each thyristor connected in series, and also to It is necessary to provide insulation between the circuits, and an electromagnetic coupling method or an optical ignition method is used to transmit the ignition signal.

FIG. 1 is a diagram showing a conventional example of a light ignition method.

The current signal generator 1, which is used as a common signal source, includes a number of light emitting elements (light emitting diodes are shown in the figure) 2-1.2-2. In which ignition pulse current is connected in series.・・・・・・2-n
to cause each light emitting element to emit light. This light emitting element 2-1
．． 2-2. ...2-n's light output is the light guide 3-1.3-2. ...3- Optical transmission using n. Each light guide 3-1.3-2,...
・The optical output of 3-n is determined by each light-receiving element (phototransistor is shown in the figure) 4-1.4-2°...4
- Convert to electrical signal with n. Each light receiving element 4-1.4-
2. ...4-n pulse output is provided by element gate circuit 5-1.5-2. . . . 5-n for pulse amplification, and main thyristor 6-1.6-2.・・・・・・6-n
ignition pulse is obtained. Note that the main thyristors 6-1, 6-2. ...5-n is shown with its voltage dividers omitted. Further, when each main thyristor is a module in which a plurality of thyristors are connected in series, the output of the element gate circuit is distributed to each thyristor by a pulse transformer.

In this method, each light emitting element 2-1, 2-2,...
By connecting . However, light emitting elements vary in their current-light output characteristics, and even with the same driving current, the light output varies. Therefore, in each light ignition system, the intensity of light at a light receiving part such as a light receiving element varies, and the sensitivity of the light receiving part varies. For this reason, there is a difference in the trigger time of the main thyristor,
A transient overvoltage would be applied to the thyristor whose turn-on was delayed, potentially destroying the element.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ignition device that can correct variations in the amount of transmitted light due to differences in light emission intensity of light emitting elements.

[Summary of the invention]

The ignition device according to the present invention has a plurality of groups in which light emitting elements are connected in series, and each group is connected in parallel so that the drive current between the groups can be adjusted, and by adjusting the drive current, it is possible to correct variations in the amount of transmitted light. This is what I did.

[Embodiments of the invention]

FIG. 2 shows an embodiment of the present invention, in which the number of groups is two. Light emitting diodes connected in series 2-1-1.2-
1-2.2-1-3 constitute one group A, and a variable resistor 7-1 for current adjustment is connected in series. Similarly, the light emitting diodes 2-2-1.2-2-2.2-2-3 constitute one group B, and are equipped with a variable resistor 7-2. Each light emitting diode in group A has light guide 3
-1-1.3-1-2.3-1-3 provides optical output to phototransistor 4-1-1.4-1-2゜4-1-3, and each light emitting diode of group B provides optical output to the phototransistor 4-2-1.4-2-2.4-2-3 via the light guide 3-2-1.3-2-2.3-2-3.

Here, variations in the sleep current-light characteristics of the light-emitting diodes can be corrected by combining light-emitting diodes with substantially the same characteristics into the same group when dividing the light-emitting diodes into groups. In this case, the absolute amount of optical output can be adjusted by variable resistor 7-1.7-2.

By grouping the light emitting diodes in this manner, variations in the light emission intensity can be easily corrected, and the problem of destruction of the main thyristor due to non-uniformity of the light ignition system can be solved. Furthermore, it is not necessary for all the light-emitting elements used to have the same characteristics, and elements with different percentages can be used in different groups, improving the yield in use.

〔Effect of the invention〕

As explained above, the ignition device according to the present invention can easily correct variations in the characteristics of the parts that constitute the optical ignition system,
It has excellent effects when applied to an ignition device that simultaneously ignites a large number of thyristors.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional light ignition type ignition device, and FIG. 2 is a block diagram showing an embodiment of the present invention.

Claims (1)

[Claims] 1. A large number of light emitting elements connected to an original signal generator, light receiving elements provided corresponding to these light emitting elements, and a large number of thyristors ignited by electrical signals from these light receiving elements. A thyristor ignition device characterized in that the plurality of light emitting elements are connected in series and parallel, and a current adjustment means is provided in the series connection portion.