JP2809913B2 - High pressure switch device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-voltage switch device used for a pulse laser pulse generator or the like.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing a conventional pulse laser pulse generator using a copper vapor laser described in Japanese Patent Application Nos. 2-32741 and 2-34252. 1, 1 is a high-voltage power supply, 2 is a charging reactor connected to the high-voltage power supply 1, 3 is a charging diode connected in series to the charging reactor 2, 4 is a charging / discharging device connected in series to the charging diode 3. Capacitor, 9
Is a high-speed switch element composed of an FET (field-effect transistor) or the like, 8 is a switch circuit composed of a series-parallel circuit of a number of high-speed switch elements 9, and is connected between the charging diode 3 and the high-voltage power supply 1. .

[0003] Reference numeral 10 denotes a reverse current suppressing element connected in series to the capacitor 4 and is constituted by a series-parallel circuit of a plurality of diodes or a plurality of magnetic saturation elements. Reference numeral 11 denotes a bypass resistor connected in parallel to the reverse current suppressing element 10, 7 denotes a laser discharge tube connected between the reverse current suppressing element 10 and the high-voltage power supply 1, and 5 denotes a charging device connected in parallel to the laser discharge tube 7. Resistance.

Reference numeral 12 denotes a gate circuit for driving the switch circuit 8, and a common gate terminal G of each parallel circuit stage of the high-speed switch element 9 such as an FET constituting the switch circuit 8.
And a common source terminal S, and a gate terminal G
Is applied.

[0005] Reference numeral 13 denotes an optical oscillator for generating an optical pulse;
Represents the light pulse generated by the optical oscillator 13 in each gate circuit 12
An optical fiber to be provided to the photoelectric conversion element inside.

A gate power supply circuit 15 supplies a power supply voltage to the gate circuit 12, and a gate power supply line 16 transmits the power supply voltage.

FIG. 6 shows the configuration of the gate circuit 12. Reference numeral 17 denotes a photoelectric conversion element for converting the light pulse transmitted through the optical fiber 14 into an electric pulse signal.
Is a bias resistor connected to the output side of the photoelectric conversion element 17, and 19 is a buffer which shapes a pulse signal output from the photoelectric conversion element 17 to form a conduction signal and adds it to the gate terminal G. The source terminal S is grounded. Reference numeral 20 denotes a connector connected to the gate power supply line 16.

FIG. 7 shows the structure of the optical oscillator 13.
Reference numeral 21 denotes an astable multivibrator for generating a repetitive pulse signal of a predetermined period, 22 a differentiating circuit for differentiating the pulse signal, 23 a buffer for shaping the differentiated pulse of the differentiating circuit 22 into a narrow pulse signal, and 24 Is an electro-optical conversion element that converts a pulse signal from the buffer 23 into an optical pulse and sends it to the optical fiber 14.

FIG. 8 shows the configuration of the gate power supply circuit 15. Reference numeral 25 denotes an AC power supply; 26, an insulating transformer to which an AC voltage of the AC power supply 25 is applied; 27, a plurality of secondary windings of the insulating transformer 26; This is a rectifier circuit that rectifies and smoothes the applied voltage and sends it to the gate power supply line 16.

Next, the operation will be described. In FIG. 5, a high voltage is slowly charged to a capacitor 4 from a high-voltage power supply 1 through a charging reactor 2, a charging diode 3, a bypass resistor 11, and a charging resistor 5. Next, when the switch circuit 8 is turned on by the conduction signal of the gate circuit 12, the high voltage of the capacitor 4 applies a pulse voltage for several hundred nanoseconds to the laser discharge tube 7 via the reverse current suppressing element 10. Thus, the laser discharge tube 7 is discharged, the discharge current i _x is the capacitor 4 flows the switch circuit 8, the laser discharge tube 7, the path of the reverse current suppressing element 10 and the capacitor 4. At this time, the reverse current suppressing element 10 suppresses the reverse current of the oscillating current due to the inductance of the circuit.

In the optical oscillator 13 shown in FIG. 7, a repetitive pulse signal output from the astable multivibrator 21 is differentiated by a differentiating circuit 22. The differentiated pulse is shaped into a narrow pulse signal by the buffer 23.

This pulse signal is converted into an optical pulse by the electro-optical conversion element 24, and the optical pulse is sent to the gate circuit 12 through the optical fiber 14.

In the gate circuit 12 shown in FIG. 6, the light pulse sent through the optical fiber 14 is converted by the photoelectric conversion element 17 into an electric pulse signal. The pulse signal is shaped by the buffer 19 to be applied to the common gate terminal G of each FET parallel circuit stage of the switch circuit 8 as a conduction signal composed of a pulse signal equivalent to the narrow pulse signal. By making it conductive,
The entire switch circuit 8 is made conductive.

In the gate power supply circuit 15 shown in FIG. 8, an AC voltage of an AC power supply 25 is converted into a DC voltage by each rectifier circuit 27 via an insulating transformer 26. This DC voltage is supplied as a power supply voltage to the connector 20 of each gate circuit 12 via the gate power supply line 16.

[0015]

The switch circuit 8 used in the conventional pulse laser pulse generator is composed of a series-parallel circuit of a number of high-speed switch elements 9 as described above. A gate circuit 12 is required for each of the parallel circuit stages, and a gate power supply circuit 15 for supplying power to each gate circuit 12 is provided.
Further, the number of optical fibers 14 required from the optical oscillator 13 to the number of stages of the parallel circuit is required, and the component configuration is large and complicated. In addition, since the gate circuit 12 is constituted by active components such as the buffer 19 and the photoelectric conversion element 17, there is a problem that an operation timing shift may occur due to a difference in characteristics.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. By forming the gate circuit almost entirely from passive components, there is little possibility that an operation timing shift due to a difference in characteristics will occur. An object is to obtain a high-voltage switch device that does not require a fiber, a gate power supply circuit, or the like.

[0017]

A high-voltage switch device according to the present invention comprises a high-speed switch element, for example, a series or series-parallel connection of FETs.
A drain terminal of T is connected to a gate terminal of the FET through a first diode, a capacitor, a reactor, and a second diode. A first resistor for discharging is connected to both ends of the first capacitor, and the reactor And a third diode having a cathode connected to a connection point of the capacitor and an anode connected to a source terminal of the FET, and a second resistor between a gate terminal and a source terminal of the FET; In this embodiment, one FET of the series circuit is ON / OFF controlled.

According to a second aspect of the present invention, there is provided a high-voltage switch device in which a speed-up capacitor and a primary winding of a transformer are connected in series between both ends of an FET, and a secondary output voltage of the transformer is connected via a diode. This is added to the gate terminal.

[0019]

The high pressure switch device according to the first aspect of the present invention
ON / OFF by controlling only one FET in the series circuit or only the FET connected in parallel with this FET
This eliminates the need for a gate circuit, an optical oscillator, a gate power supply circuit, and their wiring.

In the high voltage switch device according to the second aspect of the present invention, the voltage obtained from the secondary side of the transformer increases the gate voltage by the speed-up capacitor when the FET is turned on, thereby increasing the switching speed.

[0021]

[Embodiment 1] An embodiment of the first aspect of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 30 denotes a high-voltage switch device as a whole. 9 is a high-speed switching element,
In this embodiment, the FET 9 is used. Further, this embodiment shows a case where four FETs 9 are connected in series for simplicity.

Reference numerals 31, 32, 34, and 35 denote a first diode, a capacitor, and a capacitor connected in series between a drain terminal D at one end of the FET 9 and a gate terminal G as a control terminal.
Reactor, a second diode. 33 is a first resistor for discharging connected in parallel with the capacitor 22, 37 is a second resistor connected between the gate terminal G and the source terminal S at the other end of the FET 9, and 36 is a third diode. The cathode is connected to the connection point between the capacitor 32, the first resistor 33 and the reactor 34, and the anode is connected to the source terminal S.

Reference numeral 38 denotes an external oscillator for generating a pulse for driving the lowermost FET 9. Here the time constant determined by the first resistor 33 and the capacitor 32 is set from the sufficiently long repetition period, which is driven by the external oscillator 38.

Next, the operation will be described. Now, at point a, V
It is assumed that a voltage of ₀ is applied, and the voltage is equally distributed to each FET 9. In this state, both ends of the capacitor 32 of each stage are charged with a voltage of approximately V _0/4 . From this state, the lowermost FE
It is assumed that T9 becomes conductive. At this time, the operation is performed as shown in FIG. That is, when the lowermost stage FET 9 conducts at time t ₀ , the voltage v ₂ applied to each upper stage FET 9 tends to increase by _{１ ／} of the decrease of the lowermost stage voltage v ₁ . Thereby, the current i ₁ flows as shown in FIGS. 1 and 2, and the gate voltage v _G of each FET 9 is increased as shown in FIG. When the gate voltage v _G reaches the threshold voltage Vth,
Each upper-stage FET 9 starts to conduct.

Next, since the accumulated electromagnetic energy in the current i ₁ is the reactor 34, after the voltage rise of v ₂ is also stopped, it continued charging of the gate by a loop W shown in FIG. 1, sufficient Increase to the gate voltage v _G. When the gate voltage v _G reaches the maximum value, the gate voltage v _G is discharged with a time constant determined by the gate capacitance and the gate resistance 37 to prevent backflow in the second diode 35, and eventually returns to zero. As a result, all the FETs 9 are turned off, and again wait for the next operation.

Embodiment 2 FIG. FIG. 3 shows an embodiment of the second aspect of the present invention, in which the switching speed of the FET 9 is increased. In FIG. 3, reference numeral 39 denotes a speed-up capacitor connected to the drain terminal D; 40, a transformer whose primary winding is connected in series with the capacitor 39 and connected to the source terminal S; Is a fourth diode supplied from the secondary winding to the gate terminal G.

Next, the operation will be described. The charge stored in the speed-up capacitor 39 is
N is supplied to the gate terminal G from the secondary side of the transformer 40 through the fourth diode 41 together with N. This supply further increases the rising speed of the gate voltage v _G ,
Very fast switching speeds are obtained.

Embodiment 3 FIG. FIG. 4 shows an embodiment in which a large number of FETs 9 are connected in series / parallel.
To each of the FETs 9 connected in parallel.

[0029]

As described above, according to the first aspect of the present invention, one high-speed switch element of the series circuit of high-speed switch elements is used for drive control, and the other high-speed switch elements are provided with a diode, a resistor, and a resistor. Because it was configured to connect a circuit consisting of a capacitor, a reactor, etc., the conventional gate circuit,
The wiring of the optical oscillator, the gate power supply circuit, and the optical fiber and the like between them can be omitted altogether, so that the number of parts is greatly reduced, and stable operation can be obtained with a simple configuration. .

Further, according to the second aspect of the present invention, since the speed-up capacitor and the transformer are connected to the high-speed switching element, the switching speed can be increased.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a high-voltage switch device according to an embodiment of the present invention;

FIG. 2 is a timing chart showing the operation of the device.

FIG. 3 is a configuration diagram of a high-voltage switch device according to an embodiment of the present invention;

FIG. 4 is a configuration diagram showing another embodiment of the apparatus.

FIG. 5 is a configuration diagram of a conventional pulse generator for a pulse laser.

FIG. 6 is a configuration diagram of a gate circuit in the device.

FIG. 7 is a configuration diagram of an optical oscillator in the same device.

FIG. 8 is a configuration diagram of a gate power supply circuit in the device.

[Explanation of symbols]

 9 High-speed switch element 31 First diode 32 Capacitor 33 First resistor 34 Reactor 35 Second diode 36 Third diode 37 Second resistor 39 Speed-up capacitor 40 Transformer 41 Fourth diode

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-236623 (JP, A) JP-A-3-237811 (JP, A) JP-A-62-44067 (JP, A) JP-A-62-44067 60311 (JP, A) JP-A-4-133512 (JP, A) Japanese Utility Model Application Sho 61-134131 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H03K 17/10 H03K 17 / 12

Claims (2)

(57) [Claims] A series circuit of a plurality of high-speed switch elements or a series-parallel circuit in which a plurality of the series circuits are connected in parallel;
A first diode provided in series between one end of another high-speed switch element except one high-speed switch element of one series circuit and a control terminal of the high-speed switch element;
A capacitor, a reactor, and a second diode; a first resistor connected in parallel with the capacitor; a second resistor connected between the other end of the other high-speed switch element and the control terminal; A high-voltage switch device comprising: a third diode having a cathode connected to a connection point between the capacitor and the reactor and an anode connected to the other end. 2. A speed-up capacitor and one of transformers between one end and the other end of the other high-speed switch element.
And a control terminal of the other high-speed switch element or a high-speed switch element connected in parallel with the other high-speed switch element through a fourth diode. The high-voltage switch device according to claim 1, wherein the high-voltage switch device is supplied to a terminal.