JPS6229312A - Large current pulse power supply device - Google Patents

Abstract

PURPOSE:To attain low cost and to reduce power loss by using a thyristor at least two arms constituting a full wave rectifier circuit and providing a control circuit controlling the thyristor. CONSTITUTION:An on-gate signal being the result of detection of a capacitor voltage Vc across a smoothing capacitor C1 and controlling the conduction angle of thyristors SCR1, SCR2 to form the prescribed Vc s sent to the thyristors SCR1, SCR2 of a full wave rectifier circuit B from a control circuit T.C.U. In giving the on-signal from a control circuit C.U provided in a constant current circuit R to a gate of a switching element transistor, a MOS FET is turned on, a pulse current IF flows to a power diode DUT being a diode to be tested and the capacitor voltage Vc across the smoothing capacitor C1 is lowered. The control circuit T.C.U detects the decrease in the voltage Vc to send the on-gate signal. Thus, switching elements such as MOS FET with a low dielectric strength are used to reduce the power loss.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a large current pulse power supply device for supplying constant current and large current pulses to an element under test as a negative voltage source.

[Prior Art] For example, a large current pulse power supply device as shown in FIG. There are circuit configurations.

In the figure, King is an AC transformer that inputs 200 V AC to the primary side and outputs 20 V AC to the secondary side, and B is a full-wave rectifier consisting of diodes D1 to D4 connected to the secondary side of AC transformer T. circuit, C is a smoothing capacitor connected between the positive and negative DC output lines of this full-wave rectifier circuit, R is a constant current circuit, and this constant current circuit R is the DC output of full-wave rectifier circuit B. A field effect transistor (MO) is connected to the positive side of the line.
A switching element Tr such as SFET> and a shunt regulator SH are connected in series.

C-U is a control circuit connected to both ends of the shunt regulator SH, and necessarily controls the switching element Tr.

The DUT has an output terminal T1. This is a power diode as a device under test connected between T2.

Next, the operation of the above configuration will be explained with reference to the waveform diagram of FIG. 4.

That is, Fig. 4 (a) shows the AC voltage waveform at the zero point flowing to the secondary side under the AC transformer, Fig. 4 (b) shows the voltage waveform at the zero point on the DC output side of the wave rectifier circuit B, and Fig. C) is the current waveform flowing through the power diode DUT, and (D) in the same figure
is a waveform showing a change in the capacitor voltage Vc of the smoothing capacitor C.

Therefore, output terminal T1. When the control circuit CU gives an on signal to the switching element Tr, MOS FET in this example, at a predetermined timing to the power diode DUT connected to T2, the DUT receives a predetermined signal as shown in FIG. 4 (C). A pulse current flows, and if this OUT is, for example, a 300 A class power diode, the forward pulse current (IF) needs to be about 1,000 A, and the conduction time is 5 to 8 ms.

[Problems to be solved by the invention] Since the conventional large current pulse power supply device is configured as described above, the capacity of the smoothing capacitor C must be increased in order to make the 1F flowing to the DUT a large current. In addition, in order to prevent the capacitor voltage Vc of the smoothing capacitor C from decreasing, it is necessary to increase the charging voltage.
When the capacitor voltage VC increases, a MOS FET must use an element with a high withstand voltage. moreover,
10 to 30 MOS FETs are used in parallel depending on the size of I, and in this case, power loss increases.

As mentioned above, in conventional large current pulse power supply devices, the price increases due to the increase in the capacity of the smoothing capacitor, and the MOS FE
There were problems such as the necessity of increasing the voltage resistance of the T and an increase in power loss.

[Purpose of the Invention] This invention was made to solve the above-mentioned problems, and it is possible to reduce the capacitance of a smoothing capacitor and eliminate the need to increase the withstand voltage of switching elements such as MOS FETs. The object of the present invention is to obtain a large current pulse power supply device that is inexpensive and has low power loss.

[Means for Solving the Problems] A large current pulse power supply device according to the present invention uses thyristors in at least two arms constituting a full-wave rectifier circuit, and is provided with a control circuit for controlling the thyristors. I'll go.

[Function] The voltage across the smoothing capacitor connected between the positive and negative DC output lines of the full-wave rectifier circuit is detected, and when the capacitor voltage drops below a predetermined voltage, the two terminals of the full-wave rectifier circuit are
An on-gate signal is sent from the control circuit to the thyristor provided in each arm.

As a result, the SIRISK is turned on, the smoothing capacitor is charged to a predetermined voltage, and current also flows to the power diode OUT of the device under test.

[Embodiment] A large current pulse power supply device according to an embodiment of the present invention will be described below with reference to the circuit groove diagram in FIG. 1 and the operating waveform diagram in FIG. 2.

Note that the same or corresponding parts as in FIG. 3 showing the configuration of the conventional device are given the same reference numerals, and detailed explanation thereof will be omitted.

In Figure 1, 5CR1 and 5CR2 are full-wave rectifier circuits B
The cyrisk, T-C-U, connected to the two arms of
Gates G1. of the thyristors 5CR1 and 8CR2. G2
Sends an on-gate signal to thyristors SCR and 5CR.
This is a control circuit for controlling 2.

In other words, the control circuit T-C-U includes a smoothing capacitor C
1, and the voltage V across the capacitor C1 is
C is detected, and when the VC falls below a predetermined value, an on-gate signal is sent to the thyristors 5CR1 and 5CR2.

The configuration of the above is necessarily the same as that of the conventional device, but the thyristors 5CR1 and 5CR2, the diodes D3 .
MOS F as D4 and switching element Tr
As for ET, it is assumed that the maximum capacity is ■, which allows lightning current to flow.

Next, the operation of the above configuration will be explained.

Thyristor 5 of high wave rectifier circuit B from control circuit T-C-U
The capacitor voltage Vc of the smoothing capacitor C1 is detected and an on-gate signal is sent to CR1 and 5CR2 to control the conduction angle of the thyristors 5CR1 and 5CR2 so that the voltage becomes a predetermined VC.

In this embodiment, the capacitor voltage is set to 12V as shown in FIG. 2(C). Therefore, when the control circuit C-U provided in the constant current circuit R sends an on signal to the gate of the switching element Tr, that is, the MOS FET, the MOS FET is turned on, and the power diode DUT, which is the element under test, is turned on. Figure 2 (b)
A pulse current IF shown by flows. When this pulse current fF flows to OUT, the capacitor voltage Vc of the smoothing capacitor C1 decreases as shown in FIG. 2(C).

Next, when this capacitor voltage Vc decreases, 5CR1
, 5CR2 detects the drop in VC and sends an on-gate signal to the thyristors 5CR1 and 8CR2.

In the example of Fig. 2, the thyristor 5 is
In order to send an on-gate signal to gate G1 of CR1,
The thyristor 5CR1 is turned on, and at the same time as the smoothing capacitor C1 is charged, current also flows through the power diode DUT.

On the other hand, when the IF to the power diodes Dt and JT is cut off, the smoothing capacitor C1 is immediately charged by the thyristors 5CR1 and 5CR2, and the predetermined capacitor voltage V
When it reaches c, the flow angle of the thyristors 5CR1 and 5CR2 becomes small and becomes a steady state.

Note that, like FIG. 4(b), FIG. 2(a) shows the rectified waveform at the zero point of the high wave rectifier circuit B.

Further, in the above embodiment, thyristors are connected to the two arms of the full-wave rectifier circuit, but gate turn-off thyristors (GTO) may be used instead of these general thyristors.

[Effects of the Invention] As described above, according to the present invention, thyristors are used in at least two arms of the full-wave rectifier circuit in a large current pulse power supply, the capacitor voltage of the smoothing capacitor is detected, and the capacitor voltage is When the capacitor voltage drops, the control circuit immediately sends an on-gate signal to the thyristor gate to compensate for the drop in capacitor voltage and increase the voltage by 1q.
It is no longer necessary to set the charging voltage high in advance in consideration of the drop in capacitor voltage as in the past, which makes it possible to use capacitors with smaller capacitances, reducing manufacturing costs and reducing the need for switching elements such as MOSFETs. Compared to conventional devices, devices with lower withstand voltage can be used, and there are effects such as reduced power loss when a large number of these devices are connected in parallel.

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram of a large current pulse power supply according to an embodiment of the present invention, FIG. 2 is its operating waveform diagram, FIG. 3 is a circuit diagram of a conventional large current pulse power supply, and FIG. It is an operation waveform diagram. In the diagram, King is an AC transformer, B is a full-wave rectifier circuit, and 5C
R1 and 5CR2 are thyristors, D3 and D4 are diodes, C1 is a smoothing capacitor, and TCU is thyristor 5CR.
1,5CR2 control circuit, switching elements such as Trl and tMO3FET, CU a control circuit of the switching element Tr, and OUT a power diode as an element under test.

Claims (1)

[Claims] A switching element that includes a full-wave rectifier circuit connected to the secondary side of an AC transformer and a smoothing capacitor inserted between the positive and negative DC output lines of this full-wave rectifier circuit, and is controlled by a control circuit. In a large current pulse power supply device that supplies large current and constant current pulses to the device under test through A large current pulse power supply device comprising: a control circuit that detects and sends an on-gate signal to the thyristor when the capacitor voltage of the capacitor falls below a predetermined value.