JPH03292785A - Laser oscillator power supply - Google Patents

Abstract

PURPOSE:To protect a switching element against damage by a method wherein it is judged that a drive signal is normal or not at the inverter end of a transmission line provided between an inverter circuit and a drive signal output circuit, and when it is found that the drive signal is abnormal, a laser is made to stop oscillating. CONSTITUTION:When a drive signal is not normally given to a MOS FET 9 through the intermediary of a gate amplifier 5 due to that an optical fiber comes off from a transmitter 2 or a receiver 4 or the transmitter 2 is not turned ON because of malfunction, or when an optical signal serving as a drive signal of the MOSFET 9 becomes abnormal, the receiver 4 outputs a high or a low direct voltage output. At this point, as an input capacitor 13 of a pulse discriminating circuit 10 shuts off a direct voltage, a FET 16 is turned OFF, the output of the pulse discriminating circuit 10 becomes low, and the output of an AND circuit 11 becomes also low. In this case, a laser oscillator control circuit 1 stops the operation of an oscillation circuit 1a receiving the output of the AND circuit 11 to stop the oscillation of a laser, whereby the MOSFET 9 of the inverter circuit 6 can be protected against damage.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a laser oscillator power supply, and particularly relates to a laser oscillator power supply that prevents the switching element from being destroyed when the driving signal for the switching element becomes abnormal. be.

[Prior Art] FIG. 2 is a block diagram of a conventional laser oscillator power supply. In the figure, (1) is a laser oscillator control circuit, which is a circuit that starts, stops, and performs other controls of the laser oscillator.

Note that this laser oscillator control circuit includes an oscillation circuit (1a) as a drive signal output circuit that outputs a drive signal for driving a switching element of an inverter circuit (6), which will be described later. (2) is a transmitter that converts the electrical signal output from the oscillation circuit (Ia) included in the laser oscillator control circuit (1) into an optical signal, and (3) is the fiber end as a transmission path for transmitting the optical signal (4 ) is a receiver that converts an optical signal into an electrical signal, (5) is a gate amplifier that amplifies the electrical signal of the receiver (4), (6) is an inverter circuit driven by the gate amplifier (5), and (7) is an inverter. A transformer boosts the output of the circuit (6), (8) is an electrode that excites the laser medium by discharge, and (9) is a MOS FET that constitutes the inverter circuit (6).

Note that the laser oscillator power supply refers to (1) excluding electrode (8).
, (2), (3), (4), (5)
, (6) and (7).

Next, the operation will be explained. Laser oscillator control circuit (
The oscillation circuit (1a) in 1) outputs an electrical signal that is a drive signal to the inverter circuit (6), converts it into an optical signal by the transmitter (2), and transmits it to the receiver (4) via the optical fiber (3). do. The receiver (4) converts the optical signal into an electrical signal and provides a drive signal to the gate amplifier (5) of the MOS PET (9) that constitutes the inverter circuit (6).
FET (9) is driven.

The output of the inverter circuit (6) is boosted by a transformer (7) and applied to an electrode (8) to excite a laser medium (not shown) by discharge.

[Problems to be Solved by the Invention] In the conventional laser oscillator power supply as described above, the drive signal for the switching element of the inverter circuit (6) is transmitted via the optical fiber that is the transmission path, so it is susceptible to vibrations etc. If the end fiber is disconnected from the transmitter or receiver, or the transmitter or receiver breaks down, making it impossible to transmit or receive optical signals, the drive signal may be transferred to the inverter circuit (
M
There was a problem that the OS FET (9) was destroyed.

This invention was made in order to solve this problem, and when the drive signal of the switching element of the inverter circuit becomes abnormal, the laser oscillation is detected and the laser oscillation is immediately stopped to prevent the destruction of the switching element. The purpose is to obtain oscillator power supply.

[Means for Solving the Problems] A laser oscillator power supply according to the present invention includes an inverter circuit that applies a voltage to a discharge electrode of a laser oscillator, and a drive signal output circuit that outputs a drive signal that drives a switching element of this inverter circuit. and a transmission line for transmitting the drive signal output from the drive signal output circuit to the inverter circuit, and a drive signal discrimination circuit for determining whether the drive signal is normal or not is provided at the end of the transmission line on the inverter circuit side. and stops laser oscillation when the drive signal is abnormal based on the output of this drive signal discrimination circuit.

[Function] In the present invention, the inverter side of the transmission line provided between the inverter circuit that applies voltage to the discharge electrode of the laser oscillator and the drive signal output circuit that outputs the drive signal for the switching element of the inverter circuit. At the end, it is determined whether the drive signal is normal or abnormal, and if the result of the determination is that the drive signal is abnormal, the laser oscillation is stopped to protect the switching element.

[Example 1] An example of the present invention will be described below with reference to the drawings. 1st
FIG. 1 is a configuration diagram showing an embodiment of the present invention. In FIG. 1, the same parts as in FIG. 2 are given the same reference numerals, and the explanation thereof will be omitted. (10) is a pulse discrimination circuit, which detects abnormal transmission of an optical signal based on whether the output of the receiver (4) is a pulse. This pulse discrimination circuit receives the output of the receiver (4) via a buffer (I2) which will be described later. That is, the pulse discrimination circuit (10) is a MOS PET
It has the function of a drive signal discrimination circuit that determines whether the drive signal (9) is normal or not, and is connected to the end of the optical fiber (3) on the inverter circuit (6) side, which is the drive signal transmission path. .

(11) is an AND circuit, (12) is a buffer, (13)
is a capacitor A, (+4) is a resistor, (+5) is a capacitor B1, (16) is an FET, and (17) is an inverter.

The operation of the laser oscillator power supply configured as described above will be explained with reference to FIG. A receiver (4) that converts an optical signal into an electrical signal, which is placed before the Kate amplifier (5).
The output is passed through the buffer (12) to the pulse discrimination circuit (
lO) manually. When issuing a laser oscillation command, the receiver (
Since the output of 4) is a pulse voltage, it passes through the capacitor A (13) at the input of the pulse discrimination circuit (10) and is low-passed by the resistor (14) and capacitor B (15).
Smoothed by Low Pa5s) filter, F E
Turn on T (1B), and the output of the pulse discrimination circuit (1o) becomes the old gh. This signal and laser oscillation (beam ON)
) A logical product is performed with the signal that is the old gh during the command output, and if this is the old gh, it is determined to be normal.

If the optical fiber (3) is disconnected from the transmitter (2) or receiver (4), or the transmitter (2) is malfunctioning and does not turn on, the drive signal is transmitted normally to the MOS FET (9) via the gate amplifier (5). If it is not given, that is, No! When the optical signal that is the drive signal for the 3-FET (9) becomes abnormal, the output of the receiver (4) becomes an old gh or low DC voltage output. At this time, the pulse discrimination circuit (10
) input capacitor A (13) cuts off the DC voltage, so FET (1B) turns OFF, the output of the pulse discrimination circuit (10) becomes Low, and the output of the AND circuit (11) also becomes Low. Become. In this case, the laser oscillator control circuit (1) takes in the output of the AND circuit (11), stops the operation of the oscillation circuit (1a), and stops laser oscillation, and the MOS PET (9) of the inverter circuit (6)
prevent it from being destroyed.

Although this embodiment has been described with respect to the gate amplifier X1, similar circuits are added to the other three gate amplifiers.

In the above embodiments, the pulse discriminating circuit is explained using an electric circuit, but an element using an arithmetic processing unit, such as a micro-collector, may also be used.

Further, although the case where the transmitter and receiver are directly connected to the optical fiber has been described, connectors may be attached to both ends of the optical fiber and connected to the transmitter and receiver.

Furthermore, a cable may be used instead of an optical fiber to directly transmit the electrical signal, and the oscillation circuit output transmitted via the cable is transmitted from the front stage of the gate amplifier (5) via the buffer (12). Pulse discrimination circuit (10
) can be similarly implemented.

[Effects of the Invention] As explained above, the present invention provides a transmission system that is provided between an inverter circuit that applies a voltage to a discharge electrode of a laser oscillator and a drive signal output circuit that outputs a drive signal for a switching element of the inverter circuit. At the end of the path on the inverter side, it is determined whether the drive signal is normal or abnormal, and if the result of the determination is that the drive signal is abnormal, the laser oscillation is stopped.
Even if the drive signal is not transmitted normally for some reason, this has the effect of preventing the switching element from being destroyed. Additionally, it has the effect of making it easier to identify the location where a problem occurs during maintenance.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a laser oscillator power supply according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional laser oscillator power supply. In the figure, (1) is a laser oscillator control circuit, (1a)
is the oscillation circuit, (2) is the transmitter, <3) is the fiber end, (4) is the receiver, (5) is the gate amplifier, (
6) is an inverter circuit, (7) is a transformer, (8) is an electrode, (9) is a MOS FET, (10) is a pulse discrimination circuit, (11) is an AND circuit, and (12) is a buffer. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] An inverter circuit that applies a voltage to a discharge electrode of a laser oscillator, a drive signal output circuit that outputs a drive signal that drives a switching element of this inverter circuit, and a drive signal output circuit that outputs a drive signal that drives a switching element of this inverter circuit. A transmission line for transmitting a drive signal to the inverter circuit; a drive signal discrimination circuit connected to an end of the transmission line on the inverter circuit side for determining whether the drive signal is normal; A laser oscillator power supply comprising a laser oscillation stop circuit that stops laser oscillation when a drive signal is abnormal based on the output.