JPH0783151B2 - Laser power supply - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser power supply device including a capacitor charger for charging a capacitor that is repeatedly charged and discharged used in, for example, a carbon gas laser, and particularly stabilized charging. The present invention relates to a laser power supply device including a capacitor charger having a voltage characteristic.

[Conventional technology]

Conventionally, for example, a device as shown in FIG. 3 has been used as a laser power supply device including a capacitor charger for repeatedly charging and discharging a capacitor. In the figure, charges are accumulated in a capacitor 3 from a charging power source 1 through a current limiting impedance 2. The capacitor 3 includes a switch means 4 and a laser tube 5 which are connected in series with each other.
Are connected in parallel. When an ON signal is supplied from the drive circuit 6 to the switch means 4, the electric charge stored in the capacitor 3 is discharged and a large current is instantaneously supplied to the laser tube 5.

First, the drive circuit 6 detects the time when the switch means 4 is turned on via the isolator 7, and activates the integration circuit 12 to slowly raise the reference voltage. Then, this reference voltage is connected to one end of the comparator 10 and compared with the detection voltage obtained from the detection circuit 8. The error signal generated in the comparator 10 is supplied to the control terminal of the charging power source 1, the charging power source 1 is started up so as to obtain an output in proportion to the reference voltage, and charges are accumulated in the capacitor 3 again. Therefore, the charging power source 1 is made to rise at a predetermined inclination. In this way, the capacitor 3 is repeatedly charged and discharged to supply the necessary power to the laser tube.

[Problems to be solved by the invention]

However, in the conventional laser power supply device configured as described above, since the current flowing through the switch means 4 is several hundred amperes to several thousand amperes and the voltage is tens of thousands of volts, which is high energy, it is necessary to increase the withstand voltage of the isolator 7. There is. Further, since the laser tube side has a high voltage and high energy, there is a problem that even if the withstand voltage is simply increased, it is transmitted as a noise signal through the isolator and the circuit malfunctions.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a laser power source including a charging power source, a capacitor charged with energy from the charging power source, switch means connected in series with a laser tube, and a drive circuit for triggering the switch means. In the device, when the switch means is turned on, the detection voltage of the output voltage of the charging power supply is given to an integration circuit via a waveform shaping circuit to start the integration operation to raise the reference voltage and set the reference voltage to the reference voltage. The present invention proposes a laser power supply device characterized in that the capacitor is charged to a charging voltage that is substantially proportional.

[Action]

Since the present invention is configured as described above, first, the integrating circuit is started at each discharge time of the switching means on the laser tube side from the output voltage of the charging power source via the waveform shaping circuit. Then, the reference voltage is raised as the output of the integrating circuit, and the capacitor is charged by the charging voltage proportional to the reference voltage. In this way, even if the discharge time detection signal is not supplied from the drive circuit of the switch means on the laser tube side,
The start timing of the integrating circuit can be obtained by the circuit configuration only on the charging power source side.

〔Example〕

FIG. 1 shows a block diagram of a laser power supply device of the present invention.
In the figure, electric charges are accumulated in the capacitor 3 via the current limiting impedance 2 having a relatively low impedance from the charging power source 1. A laser tube 5 is connected from the condenser 3 via the switch means 4. When an ON signal is supplied to the switch means 4 from the drive circuit 6, the electric charge stored in the capacitor 3 is discharged and a large current instantaneously flows through the laser tube 5.

At this time, the output voltage of the detection circuit 8 suddenly becomes 0 as shown in FIG. Then, the output voltage of the comparator U1 in the waveform shaping circuit 13 changes from low level to high level as shown in FIG. 2 (b). Then, it is differentiated by the differentiator composed of the capacitor C2 and the resistor R3, and a pulse waveform as shown in FIG. 2 (c) is generated at the output point (c) of the waveform shaping circuit 13. On the other hand, from the reference voltage source 11 to the integration circuit 12
The capacitor C1 is charged through the resistor R1 inside. Then, the pulse of the output of the waveform shaping circuit 13 is sent to the base of the transistor Q1, and the charge of the capacitor C1 is once discharged and drops to a low level as shown in FIG. As the slow integration circuit 12 again
Output voltage rises. Then, the output voltage of the integration circuit 12 is connected to one end of the comparator 10 and compared with the detection voltage obtained from the detection circuit 8. In order to supply the error signal generated in the comparator 10 to the control terminal of the charging power source 1 and store the charge in the capacitor 3 again, the charging power source 1 is turned on so as to obtain an output proportional to the reference voltage. To obtain the desired capacitor charging characteristics. In this way, the capacitor 3 is repeatedly charged and discharged to supply the laser tube with necessary power.

〔The invention's effect〕

The present invention is configured as described above, and since the discharge time of the switch means on the laser tube side is detected only by the circuit on the charger side, an isolator is not required and a high voltage, large current switch is activated. This has the effect of eliminating the cause of malfunction or destruction due to the surge voltage of.

[Brief description of drawings]

FIG. 1 shows a block diagram of a laser power supply device of the present invention,
FIG. 2 is a waveform diagram of each part for explaining the operation of the laser power supply device shown in FIG. 1, and FIG. 3 is a block diagram of a conventional laser power supply device. 1 ... Charging power source, 2 ... Current limiting impedance 3 ... Capacitor 4 ... Switch 5 ... Laser tube, 6 ... Drive circuit 7 ... Isolator, 8 ... Detection circuit 10 ... Comparator 11 ... Reference Voltage source 12 …… Integrator circuit 13 …… Wave shaping circuit C1, C2 …… Capacitor R1 to R7 …… Resistor Q1 …… Transistor U1 …… Comparator

Claims (1)

[Claims] 1. A laser power supply device comprising a charging power source, a capacitor charged by the energy from the charging power source, a switch means connected in series to a laser tube, and a drive circuit for triggering the switching means. At this time, the detected voltage of the output voltage of the charging power source is applied to the integrating circuit via the waveform rectifying circuit to start the integrating operation, raise the reference voltage, and set the charging voltage to be approximately proportional to the reference voltage. A laser power supply device characterized by charging a capacitor.