JPH0341994B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an output voltage detection device for a laser oscillator, and particularly to an output voltage detection device for a laser oscillator that can be constructed at low voltage and at low cost.

[Conventional technology]

The electrical impedance of the laser tube changes depending on the state of the internal gas, etc., and as a result, the voltage supplied to the laser tube changes, and the output voltage of the high frequency power supply device changes. For example, in a laser oscillator having a current feedback loop to the laser tube, if the electrical impedance fluctuates, the supply voltage will naturally fluctuate if the current is controlled to be constant. If this is left as is, it will cause damage to the semiconductors that make up the inverter in the high frequency power supply. It is also necessary to monitor the output voltage to obtain a stable supply voltage.

For this reason, conventional methods have been to detect the output voltage of a high-frequency power supply, raise an alarm when it exceeds a standard voltage, and stop operation when it exceeds a dangerous voltage. In order to control the output voltage, it was necessary to detect and monitor the output voltage. Therefore, in laser oscillators, it is important to monitor and measure the output voltage of the high frequency power supply. Traditionally, these measurements have been made using potential transformers or split capacitors.

[Problem that the invention seeks to solve]

However, when using an instrument transformer, the voltage is quite high, so a transformer with a considerable dielectric strength is required, and since the frequency of the high-frequency power source is high, high-frequency characteristics are also required. This required a very expensive potential transformer.

In addition, with the method of dividing the voltage using capacitors, it was not possible to separate the power supply line to the laser tube from the ground on the control device side, and there was a problem that there was a high risk of noise entering the control circuit. .

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide an output voltage detection device for a laser oscillator that can be constructed at low voltage and at low cost.

[Means for solving problems]

In order to solve the above problems, the present invention provides an output voltage detection device for a laser oscillator having a step-up transformer 2 between a high frequency power source 1 and a laser tube 4, as shown in FIG. Output voltage detection of a laser oscillator characterized in that a current transformer 5 for detecting current is provided on the ground side of the laser oscillator, and the output voltage of the high frequency power supply device 1 is detected from the current of the current transformer 5. An apparatus is provided.

[Effect]

Since the current transformer is installed on the ground side of the primary winding of the transformer, the voltage of the current transformer is very low. The output voltage can be calculated from the product of the current value from the current transformer and the input impedance on the primary side of the transformer.

〔Example〕

An embodiment of the present invention will be described below based on the drawings.

FIG. 1 shows a block diagram of an embodiment of the present invention. In the figure, reference numeral 1 denotes a high-frequency power supply device, which rectifies commercial power and converts it into direct current, which is then converted into high-frequency voltage by a high-frequency inverter. Reference numeral 2 denotes a step-up transformer, which steps up the high-frequency power source from the high-frequency power supply device to a required voltage. A matching circuit 3 performs impedance matching between the transformer 2 and the laser tube, and efficiently supplies power from the high frequency power supply to the laser tube. In this embodiment, a π-type matching circuit is used. 3
1 and 33 are capacitors forming a parallel reactance, and 32 is an inductance forming a series reactance.

4 is a laser tube. A tube 41 is made of quartz glass or the like, and a laser medium gas 42 is circulated inside. 43a and 43b are electrodes, and high frequency power is applied to the tube 41 through these electrodes. Laser medium gas 4 inside this tube 41
2, a high-frequency power source generates a discharge to oscillate and amplify laser light. The direction of the laser beam is perpendicular to the plane of the paper.

Reference numeral 5 denotes a current transformer, which is provided at the ground on the primary side of the transformer 2. Therefore, the voltage of the current transformer 5 is very low, and the insulation voltage of the current transformer 5 is low. Furthermore, the ground of the current transformer 5 is separated from the power line for laser discharge, and the possibility of noise being mixed in is low.

Reference numeral 6 denotes a control device that can calculate the voltage of the high frequency power source output from the high frequency power supply device 1 from the product of the current signal value from the current transformer 5 and the input impedance on the primary side of the transformer. This can be obtained by converting the current signal value from the current transformer 5 into a digital value using a DA converter, storing the input impedance value on the primary side of the transformer as a digital value in advance, and then multiplying the two values. .
This detected voltage can protect FETs and the like used within the high frequency power supply 1.

These voltage values are compared with a predetermined reference voltage value, and if the reference voltage value is exceeded by a predetermined value or more, an alarm is displayed. Also, if this voltage value reaches a dangerous voltage or higher, the exercise will be stopped. Furthermore, this voltage can be monitored and controlled automatically to keep it constant.

In the above description, a current transformer is provided on the primary side of the transformer, but the transformer 2 may be configured as a three-turn transformer without providing a special current transformer.

〔Effect of the invention〕

As explained above, in the present invention, the output voltage of the high frequency power supply device is detected from the current detected from the current transformer provided on the ground side of the primary side of the transformer. voltage is low,
An inexpensive current transformer can be used, and the output voltage of a high frequency power supply device can be measured with a simple configuration.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention. 1...High frequency power supply device, 2...Transformer, 3...
...Matching circuit, 4...Laser tube, 5...Current transformer.

Claims (1)

[Scope of Claims] 1. In an output voltage detection device for a laser oscillator having a step-up transformer between a high-frequency power supply and a laser tube, a current transformer for detecting current is provided on the ground side of the primary side of the transformer, and the transformer comprises: An output voltage detection device for a laser oscillator, characterized in that it is configured to detect the output voltage of the high frequency power supply device from the current of the current.