JPH029218A - Pulse generator - Google Patents

Abstract

PURPOSE:To eliminate the need for a charging high voltage power supply, to select a low voltage charging power supply and to expand the output voltage variable range by storing an electric energy by a reactor and varying the conductive state of a superconducting material so as to change the switching by means of a changeover means. CONSTITUTION:The conducting state mode of a superconducting material 2 is kept to the superconducting state. In this state, when a switch 9 is closed, a current flows through a loop of power supply 7 power impedance 8 switch 9 reactor 5 superconducting material. When a current I flowing to the reactor 5 reaches a prescribed value and the switch 9 is opened, the said current loop changes to a loop of reactor 5 superconducting material 2 diode 6. In this state, when the conducting state mode of the superconducting material 2 is selected to the normal conducting state from the superconducting state, the current flowing so far to the superconducting material 2 is commutated to the capacitor 1, which si charged. The charging voltage in this case shows a rapid voltage leading from the state of voltage 0.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a pulse generator suitable for use as a power source for lasers, ion beams, etc. that require steep rising voltages and currents.

[Prior Art] In general, power sources for lasers require voltages and currents with particularly steep rises, and conventional pulse generators used as power sources for such lasers include those shown in Fig. 2. be. This figure 2 is, for example, published in Japanese Patent Application Laid-Open No. 60-961.
1 is a circuit diagram of a conventional pulse generator disclosed in Japanese Patent No. 82; FIG.

Pulse generation requires switching of some kind of switching element, but one switching element can produce a steep pulse voltage (for example, a rise time of 100 nm) for applications such as lasers.
In order to generate a voltage of about s), the voltage, current peak, and steepness of the switching element are largely responsible, and there is a limit to the use of conventional switching elements such as thyratrons and thyristors alone, and it is difficult to increase the output of the laser. The increased capacity of pulse generators associated with this has required the development of auxiliary switching means that alleviates the responsibility of conventional switching elements.

Therefore, in the conventional device shown in FIG. 2, a saturable reactor SI and capacitors C1 to C3 are combined.
A so-called magnetic switch is used as an auxiliary switching means for switch S.

To explain the operation of this conventional device, after each capacitor C□, C2 is charged to a terminal voltage U0 through a resistor R by a DC power supply HV, a switch S connected in parallel to the capacitor C1 is turned on. S, reactor L6. A loop current flows through capacitor C□, and the polarity of the terminal voltage of capacitor C1 is reversed (LC inversion method)
However, if it is assumed that the saturable reactor S1 has a large inductance in an unsaturated state during this process, then L
The reversal voltage has approximately the same peak value as during charging, and only the polarity is reversed. Therefore, at this point, the saturable reactor SI
, the terminal voltages of each of capacitors C□ and C2 are added in series, and a voltage of twice the voltage U0 charged to capacitor C2 is first applied, but this If the saturation magnetic flux of the saturable reactor SI is set so that the saturable reactor SI becomes saturated at a certain point in time, the inductance value of the saturable reactor SI changes as the state of the saturable reactor SI suddenly changes from unsaturated to saturated. suddenly changes from large to small.9 When the saturable reactor SI is magnetically switched in this way, the 12 U voltage charged in the series circuit of capacitors C, , C, transfers to capacitor C3. For simplicity, capacitor c.

Assuming that the resistance component of the loop of C2, saturable reactor SI, and capacitor C1 is 0, and the capacitor C2 charging coil Loc is infinite, capacitor C3 is about to be charged to 2tJ, and the capacitor C) is parallel to the capacitor C). Supplies a voltage U, to a load R+, connected to.

In the above operation, ↑first, the time to reverse the polarity of capacitor C2 and the time to transfer the series added voltage of capacitors C□ and C7 to capacitor C□ are the capacitor values C, ,
If C,,C, are given λ, the inductance L is set so that the former is longer. The above C when the reactor is saturated
It can be made longer by making it larger than the transition loop inductance. The responsibility of the switch S in this case is: (1) The voltage responsibility is the charging voltage U. ■ Current steepness (dj/dt) duties are U, /L. , ■The current peak duty is Uo・ff';, /T, , so the inductance L0 causes the switch S
responsibilities are reduced.

[Problems to be solved by the invention] Since the conventional pulse generator is configured as described above, a high voltage power supply (HV) is required for charging, and the conditions of the magnetic switch are such that the voltage applied to the saturable reactor SI is There were problems such as the variable range of the charging voltage was narrow and the variable range of the output voltage was also narrow because the charging voltage depended on the applied voltage.

The present invention was made to solve the above-mentioned problems, and an object of the present invention is to provide a pulse generator that does not require a high voltage power supply and can have a wide variable range of output voltage.

[Means for Solving the Problems] A pulse generator according to the present invention includes a series circuit of a capacitor and a superconductor connected in parallel to each other, a reactor and a diode connected in parallel to the superconductor, and the above-mentioned series circuit. A series circuit of a power supply and a switch connected in parallel to the diode and the conductivity state of the superconductor are
Alternatively, a switching means for switching to normal conductivity is provided, and a pulse output is obtained by the terminal voltage of the capacitor and jl.

[Function] In the pulse generator which is most suitable for the present invention, when the superconductor is brought into the superconducting state by the switching means and left in the superconducting state, the terminal voltage of the capacitor becomes 0 in a short-circuited state, and the current from the power source closes the switch. This allows the reactor to flow through the superconductor. Now, when the switch is opened, the current flows through the reactor,
The current flows along the loop of the superconductor and diode, and in this state, when the switching means switches the superconductor from superconductivity to normal conductivity, the electrical energy accumulated by the current flowing through the superconductor and reactor is commutated to the capacitor. , this capacitor is charged and its terminal voltage shows a steep rise from the O state. The terminal voltage of this capacitor is then used as a pulse output.

[Embodiments of the Invention] Hereinafter, an embodiment of the present invention will be explained with reference to the drawings.
In the figure, 1 is a capacitor, 2 is a superconductor having two modes of conduction, superconductivity and normal conductivity, and the capacitor 1 is connected in parallel. In addition, 3 is an external magnetic field application coil (switching means) that applies an external magnetic field to the superconductor 2.
This coil 3 generates an external magnetic field by supplying a control current from a control power source (not shown) through control terminals 4, 4, and switches the conductivity state of the superconductor 2 to superconductivity or normal conductivity.

Furthermore, a series circuit of a reactor 5 and a diode 6 is connected in parallel to the superelectric 4 body 2, and the diode 6 is connected to a power source 7. A series circuit of a power supply impedance 8 and a switch 9 is connected in parallel.

Next, the operation of the device of this embodiment will be explained.

First, the conduction state mode of the superconductor 2 is set to the superconducting groove state. In other words, both ends of the capacitor 1 are completely short-circuited and the terminal voltage is set to O.

In this state, when switch 9 is closed, power supply 7 → power supply impedance 8 → switch 9 → reactor 5 → superconductor 2
Current flows in the loop. For simplicity, if we assume that the voltage of the power supply 7 is the DC voltage E, the value of the power source impedance 8 is the resistance R, and the inductance of the reactor 5 is L, the current flowing through the reactor 5 is I = (E / R) ( 1-
When this current reaches a predetermined value, the switch 9 is opened, and the above current loop changes to a loop of reactor 5 → superconductor 2 → diode 6.

In this state, current is passed through the external magnetic field applying coil 3 from a control power source (not shown) connected to the control terminals 4, 4.
When the conductivity mode of the superconductor 2 is changed from superconductivity to normal conductivity, the current that had been flowing through the superconductor 2 is commutated to the capacitor 1, and the capacitor 1 is charged.

The charging voltage at this time is ideally l go 7 - I (
However, L is the inductance of the reactor 5, C is the capacitance of the capacitor 1, and I is the predetermined current value supplied by the power supply 7.
It will show your enthusiasm.

The terminal voltage of the capacitor 1 is then supplied as a pulse output to a load (not shown) connected in parallel to the capacitor 1.

In this way, according to the device of this embodiment, by storing electrical energy using the current flowing through the reactor 5, a high voltage power source for charging can be made unnecessary. In addition, switching changes the conductive state of the superconductor 2 to the coil 3.
Since the output voltage is controlled at any given time, the variable range of the output voltage depends only on the charging current, and there are far fewer restrictions than in conventional devices.

In addition, in the above embodiment, a case has been described in which the magnetic field by the coil 3 is used as a means for switching the conductive state of the superconductor 2 to superconductivity or normal conductivity, but it is also possible to control the temperature of the superconductor 2 by heating with a heater, The conduction state may also be switched, and in this case, the same effects as in the above embodiment can be achieved.

[Effects of the Invention] As described above, according to the present invention, while electrical energy is stored using a reactor, the switching operation for obtaining a steeply rising pulse output is performed by changing the conductive state of the superconductor. Since this is configured to be performed by changing the output voltage using a switching means, there is no need for a high-voltage power supply for charging, and switching can be controlled at any time, and the variable range of the output voltage depends only on the charging current. , that restriction is greatly reduced. In this way, Mitsuru? ! It is possible to lower the voltage of the power supply and expand the output voltage variable range, resulting in lower costs and higher functionality.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a pulse generator according to an embodiment of the present invention, and FIG. 2 is a circuit diagram showing a conventional pulse generator. In the figure, go - capacitor, 2... - superconductor,
3-. Coil for applying external magnetic field (switching means), 5-. Reactor, 6-.- diode, 7-.. power supply, 9-.- switch. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] A series circuit of a capacitor and a superconductor connected in parallel to each other, a series circuit of a reactor and a diode connected in parallel to the superconductor, a series circuit of a power supply and a switch connected in parallel to the diode, and the superconductor 1. A pulse generator, comprising: switching means for switching a conductive state of a body to superconductivity or normal conductivity, and a pulse output is obtained as a terminal voltage of the capacitor.