JPH0413951B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steep wave impulse voltage generator (hereinafter referred to as a steep wave generator).

High voltage wavefront length 50ns for steep wave impact voltage test
A steep rising pulse voltage waveform of ~200 ns and a wave tail length of 0.2 μs to 1 μs is required. Since such a steep wave generator is required to have extremely low inductance, the circuit elements, including their structure, must be miniaturized. In addition, with miniaturization, high voltage insulation materials are required for insulation.

There are steep wave generators that utilize discharge between spherical electrodes and have one or two stages of spherical gaps, but the higher the voltage, the larger the diameter of the spherical electrodes and the higher the manufacturing cost. If the voltage is increased to one or two stages of ball gaps, the starting characteristics will become extremely poor, and the circuit constants will become such that a steep impulse voltage waveform cannot be obtained.

The circuit diagram of a conventional steep wave generator with one stage of sphere gap is constructed as shown in Figure 1, where C is a capacitor, A is a high voltage terminal, B is an output terminal, and R is a high voltage terminal.
is a discharge resistor, and F is a low voltage connection bar. _Q1 , _Q2
is a spherical electrode, and G is a spherical gap between spherical electrodes Q ₁ and Q ₂ , between which a discharge is caused. Further, as a feedback circuit on the low voltage side, a low voltage terminal D of the discharge resistor R and a low voltage terminal I of the main capacitor C are connected by a low voltage connection bar F.

To explain the operation in this case, the main capacitor C
Then, charge the pulse voltage from the charging terminal T _R1 . This means that a pulse voltage is applied between the high voltage terminal A and the output terminal B. When the charging voltage of the main capacitor C reaches its maximum, a gap G between the bulbs Q ₁ and Q ₂ is maintained to cause a self-destructive discharge to occur. Since the high voltage terminal A and the output terminal B are short-circuited, the potential of the main capacitor C is transferred to the high voltage part (output terminal B) of the circuit element discharge resistor R that determines the tail of the steep impulse voltage waveform. The low voltage side of the main discharge circuit is connected to the low voltage terminal D of the discharge resistor R through the low voltage connection bar F to the low voltage terminal I of the main capacitor C.
Return to. Output terminal B is a test object connection terminal when performing a steep wave impact voltage test. The drawback of this conventional steep wave generator is that when increasing the voltage, the gap between the balls is made longer in one stage, which causes a delay in the discharge time.
The wavefront length of the rising portion of the steep impulse voltage waveform becomes longer, making it impossible to obtain a predetermined steep impulse voltage waveform. And the dispersion of discharge increases significantly. Therefore, the steep wave impulse voltage was limited in terms of economy and generated waveform, and the starting characteristics were short in width.

The present invention aims to eliminate these deficiencies and provide a steep wave generator that can provide a wide range of significantly improved starting characteristics, a high voltage that could not be produced in the past, and a stable and reliable steep wave shock voltage. It is.

The present invention will be explained below with reference to embodiments shown in FIGS. 2 and 3.

Figure 2 is a circuit diagram of the steep wave generator, where C is the main capacitor, A is the high voltage terminal, B is the output terminal, R is the discharge resistor, F is the low voltage connection bar, L is the pulse transmission coil, and X is the test object. It is a thing. Q ₂₂ is a hemispherical electrode with an insulated needle end, Q ₁ …Q _(o+1)1 is a hemispherical electrode, and hemispherical electrode Q ₂₁
and Q ₂₂ , Q ₃₁ and Q ₃₂ . . . Q _o1 and Q _o2 are electrically connected, respectively, and intermediate connection electrodes W ₁ … W _(o-1) are led out between them. G ₁ , G ₂ ...G _o is hemispherical electrode Q ₁ and
Q ₂₁ , Q ₂₂ and Q ₃₁ ...A discharge is caused between the spheres of Q _o2 and Q _(o+1)1 , respectively. Further, the gap length of the spherical gap G ₁ is always set to one half of the gap length of the other spherical gaps G ₂ . . . G _o .

C ₁₁ ...C _{1 (o-2)} connects every other intermediate electrode W ₁ ...W _(o-2) to the connection circuit between high voltage terminal A and output terminal B,
The voltage dividing capacitors C ₂₁ ...C _{2 (o-2)} inserted before and after each connection point connect the intermediate connection electrodes W ₂ ...W _(o-3) remaining between the high voltage terminal A and the output terminal B, Connect with W _(o-1) .

One design example of this device is a hemispherical electrode Q ₁ ...
If the diameter of Q _(o+1)1 is 15 cm, the capacitance of the capacitor is C ₁₁ and C _2(o-2) is 1000 pF, C ₁₂ …C _1(o-2) , C ₂₁
...C _{2 (o-3)} is 500 pF, and the voltage applied to the capacitor C ₁₂ ...G _{2 (o-3)} is set to be twice the voltage applied to the capacitors C ₁₁ and C _{2 (o-2)} . The capacitance of this capacitor is not fixed to this value, but may be appropriately selected depending on the diameter of the hemispherical electrode, etc.

Under these conditions, the charging terminal is connected to the main capacitor C.
Charge the pulse with a higher voltage than T _R1 . This means that a high voltage pulse is applied between high voltage terminal A and output terminal B, and capacitors C ₁₁ ...C _1(o-2) , C ₂₁ ...
The voltage is divided by C _2(o-2) , and an equal voltage is applied to each spherical gap G ₁ ...G _o .

When the potential of the main capacitor C reaches the highest high-voltage pulse voltage, a trigger pulse voltage is applied to the trigger pulse terminal T _R2 to cause a discharge in the spherical gap G ₂ through the pulse transmission coil L, and the hemispherical electrode Q ₂₂ , Since the potential of Q ₁ is the same as the potential of hemispherical electrode Q ₃₁ and the gap length of the sphere gap G ₁ is set to half of the gap length of the other sphere gaps, there is no other gap in the sphere gap G ₁ . A voltage with a potential gradient twice that of the voltage applied to the sphere gap G 1 is applied, and a discharge automatically occurs in the sphere gap G ₁ .

As a result, the ball gap G ₃ also becomes 2 of the initial applied voltage.
As a result, a discharge will automatically occur in the sphere gap _G3 . In this way, high voltage terminal A and output terminal B are short-circuited. The discharge in this case is different from that of the conventional example. A trigger pulse voltage is applied from the trigger pulse terminal T _R2 , and a discharge occurs in the spherical gap G ₂ between the hemispherical electrode Q ₂₂ with an insulated needle end of the trigger electrode and the hemispherical electrode Q ₃₁ . By increasing the gap voltage of the next stage bulb gap more than twice, the discharge time is delayed,
It is possible to reduce variations in discharge and cause stable discharge. In addition, by inputting a trigger pulse with an arbitrarily controlled delay time to the trigger pulse terminal T _R2 , stable discharge can be obtained, and the starting characteristics can be significantly improved. This means that the high voltage terminal A and the output terminal B are short-circuited due to the gap between the series multi-stage balls, and the main capacitor C is connected to the high voltage part (output terminal B) of the discharge resistor R that determines the wave tail of the steep wave shock voltage waveform. The potential of is shifted. The low voltage side of the main discharge circuit is then fed back from the low voltage terminal D of the discharge resistor to the low voltage terminal I of the main capacitor through the low voltage connection bar F. Output terminal B is a test object connection terminal when performing a steep wave impact voltage test. The pulse transmission coil L is a series multistage ball gap.
When G ₁ ...G _o is in a discharging operation, the potential of the main capacitor C changes, but it has a high impedance against steep waves and measures a high withstand voltage.

Therefore, the steep wave generator according to the present invention has a delay in discharge time, a stable discharge with little variation in discharge, even when a trigger pulse whose delay is controlled arbitrarily is input, and a significantly improved starting characteristic with a wide range. Become something. In this type of series multi-sphere gap, a hemispherical electrode Q, a capacitor C, and an intermediate connection electrode W can be stacked to easily increase the voltage. When the steep wave generator according to the present invention is used in a steep wave shock voltage test, a stable steep wave shock voltage waveform of high voltage can be applied to the test object with very little delay in discharge time and variation in discharge. I can do it.

FIG. 3 shows an example of the assembly and arrangement of the steep wave generator.
(Those with the same name as those shown in the circuit diagram in Figure 2 are given the same symbol.) The main capacitor part consists of frames 7, 8 made of insulating material,
9 and 10 (frame 9 in Figure 3 is placed on the back side of frame 8 and frame 10 on the back side of frame 7), the main capacitor C is placed in it, and placed on the insulating stand 17. do. The upper part of the main capacitor C is framed by a charging terminal T _R1 which also serves as a cover plate, and the lower part of the main capacitor C is connected to the main capacitor low voltage terminal I. The charging terminal T _R1 and the low voltage terminal I of the main capacitor C are electrically connected to the main capacitor C, respectively. The series multistage ball gap portion is made of insulating material frames 3, 4,
5 and 6, a high-voltage frame fitting that also serves as the high-voltage terminal A, and a frame fitting that also serves as the output terminal B, and are formed inside the frame. 1 ₁ and 1 ₂ are fixed rods made of insulating material that fixedly support hemispherical electrodes Q ₃₁ ...Q _o1 with intermediate connection electrodes W ₁ , W ₂ ...W _(o-1) , 2 ₁ and 2 ₂ are hemispherical electrodes This is a support rod made of an insulating material that fixedly supports Q ₁ , Q ₂₂ ...Q _o2 with intermediate electrodes W _S1 , W _S2 ... W _so .
Further, the fixing rods 1 ₁ and 1 ₂ are fixedly supported by a high voltage frame metal fitting that also serves as a high voltage terminal A and a frame metal fitting that also serves as an output terminal B. The hemispherical electrode Q _(o+1)1 is fixedly supported on the high-voltage terminal A and also serves as an electrical connection. Capacitor C ₁₁ ,
C ₁₂ C _1(o-2) is between each intermediate connection electrode W ₁ , W ₃ ...W (o-2) derived from each hemisphere electrode Q ₃₁ , Q ₅₁ ...Q _{(o-1 )1.} Fixed and electrically connected. Capacitors C ₂₁ , C ₂₂ ...C _{2 (o-2)} and each hemispherical electrode W ₂ ...W _(o-3) ,
It is fixed and electrically connected between each of W _(o-1) . In addition, capacitors C _{1 (o-2)} and C _{2 (o-2)} are fixed to high voltage terminal A, which also serves as electrical connections, and capacitors C ₁₁ and C ₂₁ are fixed to output terminal B, which also serves as electrical connections. Supported. 21 is an insulating support plate for the hemispherical electrode _Q21 , which is also fixed to the fixing rod ₁₂ .
Reference numeral 19 denotes a ball gap adjuster, and by operating this, the support rods 2 ₁ and 2 ₂ simultaneously move left and right, allowing the ball gaps G ₁ , G _{2 .} . . G _o to be adjusted simultaneously. Gap between spheres G ₁ ,
The length of G ₂ ...G _o is appropriately adjusted by the ball gap adjuster 19 according to the charging voltage of the main capacitor C.

Hemispherical electrodes Q ₂₁ and Q ₂₂ , Q ₃₁ and Q ₃₂ . . . Q _o1 and Q _o2 are electrically connected by flexible lead plates, respectively.

Frames 11, 12, 13, 14 made of insulating material
(In Figure 3, the frame 13 is placed on the back side of the frame 12, and the frame 14 is placed on the back side of the frame 11.)
A discharge resistor R is placed and attached on the outside. Further, on the inside, a pulse transmission coil L is arranged, which is formed by winding a coaxial cable around a hollow support cylinder made of an insulating material and forming it into a coil shape.

The high-voltage part of the discharge resistor R is fixedly supported and electrically connected to a metal frame that also serves as an output terminal B, and the low-voltage terminal D of the discharge resistor is connected to the low-voltage connection bar R. The low voltage connection bar F is also connected to the main capacitor low voltage terminal I, forming a main discharge circuit on the low voltage side. The low-voltage connection bar F is arranged so that it is electrically insulated from the pedestal that also serves as the ground terminal 20 by insulating stands 17 and 18, taking noise countermeasures into consideration when measuring voltage. The above-described main capacitor section, pulse transmission coil section, and discharge resistor section are arranged on a pedestal that also serves as the ground terminal 20.

In addition, an insulating stand 16 is installed on the main capacitor part (the charging terminal T _R1 which also serves as the cover plate of the main capacitor C), and the high voltage terminal A side of the multi-stage ball gap is placed on top of the insulating stand 16, and the frames 3, 4, 5 , 6 are fixedly supported.

The discharge resistor R is attached to the output terminal B side of the multi-stage bulb gap and is fixedly supported by a frame framed by frames 11...14.The main capacitor charging terminal T _R1 and the high voltage terminal A are electrically connected with a lead wire. ing.

The circuit diagram shown in Figure 2 can be realized by the steep wave generator with the above structure, and it has significantly improved starting characteristics as described above, a wide range of operation, high voltage that could not be produced conventionally, and stable and reliable steep wave generation. A wave shock voltage is obtained. Then, based on the above-mentioned embodiment, a steep wave generator with 15 stages of ball gaps was manufactured,
Output voltage 2000KV, steep wave shock voltage waveform, wavefront length
A wave length of 180 ns and a wave tail length of 1 μs were obtained.

Furthermore, the stability of discharge variation was less than 30 ns.

As described in detail above, the steep wave generator according to the present invention has significantly improved starting characteristics and stable high output, and is of extremely high industrial and practical value.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of a conventional steep wave shock voltage generator with one stage of ball gap, Fig. 2 is a circuit diagram of an embodiment of the steep wave shock voltage generator of the present invention, and Fig. 3 is a circuit diagram of a steep wave shock voltage generator of the present invention. An example of the arrangement of a wave impact voltage generator, where A is a front view and B is a side view. C: Main capacitor, _C11 , _C12 ...C1 _(o-2) , _C21
C ₂₂ ...C _2(o-2) : Voltage dividing capacitor, G ₁ , G _2-
G _o : Spherical gap, L : Pulse transmission coil, Q ₂₂ : Hemispherical electrode with insulated needle end of trigger electrode.

Claims (1)

[Claims] 1 Connect multiple sets of bulbs in series in multiple stages, and connect voltage dividing capacitors alternately in parallel between the bulbs so that the voltage between each bulb is equal, and connect the high voltage charged in the main capacitor in parallel. voltage,
By applying a trigger pulse to the trigger electrode provided between the spheres, the spheres are successively short-circuited,
In the steep wave shock voltage generator that discharges electricity through the bulbs connected in multiple stages in series, a pulse transmission coil made of a coaxial cable formed into a coil is disposed on the output side of the bulbs connected in multiple stages in series, A steep wave impulse voltage generator characterized in that a trigger pulse is applied through the pulse transmission coil.