JPS6331183A - High voltage dc pulse generator for primary controlled gas laser - Google Patents

Abstract

PURPOSE:To realize reduction in size and extended service life of apparatus by controlling a load current with a DC voltage of a DC-DC converter and controlling ON and OFF an inverter switch circuit with the specified time interval in the primary side of a booster transformer to generate a DC high voltage pulse. CONSTITUTION:A commercial AC input is rectified into DC by a rectifying circuit 1, the rectified output is controlled and converted to a DC voltage corresponding to an output current by a converter 2 and moreover it is converted to high frequency AC by an inverter switch circuit 3. An output voltage of the high voltage rectifying circuit 5 becomes a rectangular wave pulse by repeatedly controlling the inverter switch circuit 3 for ON and OFF with the desired duty higher than the carrier frequency or higher in the primary side n1 of the booster transformer 4 and thereby a load current waveform applied to a gas laser 8 has a constant current pulse. Accordingly, a conversion frequency of high voltage DC pulse generating circuit for gas laser can be increased, size reduction can be realized and service life can also be extended by employing a semiconductor switch.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a circuit for generating DC high voltage pulses for a gas laser device. Conventionally, in gas laser equipment that requires high DC voltage, the output and flow are controlled by a saturable reactor SR, as shown in Figure 1.
The control AC by the saturable reactor SR is transferred to the step-up transformer T.
DC high voltage pulses were obtained by increasing the voltage and opening and closing the vacuum tube VT, which floated the rectified and smoothed output. In the conventional system, the operating frequency is combined with the commercial 'a source's same frequency C.
Therefore, the response of the control circuit becomes slow and the size of the transformer T becomes unavoidable.

Furthermore, since a vacuum tube vT is used as a switch, the operating life is short and it is uneconomical. It is an object of the present invention to solve these problems.

2 and 5 are circuit diagrams of an embodiment of the present invention and operation waveform diagrams of each part thereof. In the figures, 1 is a rectifier circuit, 2 is a DC-DC converter, 3 is an inverter switch circuit, 4 is a step-up transformer, and 5 is a A high-voltage rectifier circuit, 6 a parasitic resistor, 7 a capacitor, and 8 a gas laser tube. 3 and 4 respectively show a basic circuit example of a converter (step-down converter) and a circuit example of an inverter switch applied to the embodiment of the present invention, and sw, , sw, ~SW in FIG. These are switching elements such as transistors 1, MO8FETs, and thyristors. The operation will be explained below with reference to FIG. First of all,
In Figure 2, the rectifier circuit 1 rectifies the commercial AC input AC into DC (see the voltage waveform in Figure 5 (a)), and the rectified output is converted to a converter 2 (step-down converter shown in Figure 3).
The output current is controlled and converted into a DC voltage corresponding to a desired output current (see the voltage waveform in FIG. 5(o)). converter 2
The DC output of the inverter switch circuit 3 (Fig. 4 a, b
, e) is converted into high-frequency alternating current. If this inverter switch circuit 3 is repeatedly operated and stopped at a desired duty higher than the carrier frequency on the primary side nl of the step-up transformer 4 (see the voltage waveform in Figure 5 e), the high voltage rectifier circuit 5 The output voltage waveform of is a square wave pulse (see voltage waveform in FIG. 5), and the load current waveform applied to the gas laser tube 8 is a current pulse shown in FIG. 5(e). Carrier circumference S of inverter switch circuit 3:
If the number is sufficiently high, the ripple reduction capacitor 7 is not necessary. According to the present invention, the conversion frequency of the DC high voltage pulse generation circuit for gas lasers can be increased, so the response speed is increased.

Also, it can be made smaller. Furthermore, the use of semiconductor switches increases the lifespan. Since the DC high voltage pulser for pulser mode operation is controlled on the primary side, that is, the low voltage side, of the step-up transformer, it is possible to output continuously up to the comparative mode.

[Brief explanation of the drawing]

The diagram shows an example of a conventional high voltage DC pulse generation circuit for gas lasers. FIG. 2 is an example of a DC high voltage pulse generation circuit for gas lasers according to the present invention. Figure 3 is an example of a basic circuit using a step-down converter of a DC-DC converter. Figure 4 is an example of an inverter switch circuit. FIG. 5 shows operating waveforms of the circuit of the present invention. 1... Rectifier circuit, 2... DC-DC converter, 3
- Inverter switch circuit, 4... Step-up transformer 5... High voltage rectifier circuit, 6... Ballast resistor, 7...
...Condenser, 8...Gas laser tube. Patent applicant Shindengen Kogyo Co., Ltd. 1st 4th trial

Claims (1)

[Claims] A rectifier circuit that rectifies AC input into DC, a DC-DC converter that converts the rectified output into a desired DC voltage, and the D
A DC high voltage pulse generator consisting of an inverter switch circuit that converts the DC output of the C-DC converter into high frequency AC, a step-up transformer, a high voltage rectifier circuit, and a ballast resistor that stabilizes the control of the negative resistance characteristic region of the gas laser load. In the circuit, the load current is controlled by controlling the DC voltage of the DC-DC converter, and the DC high voltage pulse is generated by repeatedly operating and stopping the inverter switch circuit on the primary side of the step-up transformer at desired time intervals. A direct current high voltage pulse generation circuit for a primary control gas laser, characterized in that it generates.