JPH0343805B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pulse generator mainly used in fields such as electronic measurement and physical measurement.

(Prior Art) Generally, pulse generators are widely used in the adjustment of various electronic devices, physical measurements, and the like.

Conventionally, this type of pulse generator has been constructed by connecting a capacitor Co, a discharge gap G having a trigger terminal 1, and resistors Rs and Ro in a closed loop, as shown in FIG.
It is well known that a capacitor Cf is connected to both ends of the resistor Ro so that pulses are obtained from both ends of the resistor Ro.
A coaxial plug 3 of the coaxial cable 2 for transmitting the pulse is connected to both ends of the resistor Ro. The capacitor Co is charged with an electric charge from a DC power supply (not shown) connected to the charging terminal 4 through the charging resistor Rc, and when a trigger voltage is applied to the trigger terminal 1 of the discharge gap G, this electric charge is The pulse is discharged through the discharge gap G, the resistors Rs and Ro, and the capacitor Cf, and a pulse is taken out from the coaxial cable 2.

By the way, in a pulse generator having a circuit configuration as shown in Fig. 4, in order to obtain a pulse with a fast rise, the shape is designed to be as small as possible and the wiring to be short. It is not possible to reduce the inductance of Cf lead wires and wiring to zero. For this reason, as shown in Fig. 5, which shows an equivalent circuit when the electric charge charged in the capacitor Co is discharged, a voltage of about 3.0 μH to 1.0 μH due to the above-mentioned lead wire and its wiring is inevitably present in the discharge path of the electric charge of the capacitor Co. A residual inductance L is generated. Therefore, a high frequency vibration 5 as shown in FIG. 6 is superimposed on the output pulse, and the quality of the pulse waveform deteriorates.

Therefore, the residual inductance L of about 3.0 μH to 1.0 μH is treated as an unavoidable constant, and as shown in FIG. 4, a resistor Rs is inserted between the discharge gap G and the resistor Ro as a damping resistance for high frequency vibration. However, if the high frequency vibration is large, the value of the control resistor Rs must also be large.
There was a problem that the pulse output from the pulse generator slowed down and the output efficiency also decreased. Incidentally, the pulse rise time obtained by a conventional pulse generator of this type was about 1 μs at most, as shown in FIG.

(Object of the Invention) An object of the present invention is to provide a pulse generator that does not generate high-frequency vibrations and outputs high-quality pulses that rise quickly.

(Structure of the Invention) For this reason, the present invention includes a first capacitor having a cylindrical structure, one end of which is connected to a DC power source and the other end of which is grounded, and the electric charge of this first capacitor is temporarily discharged. A first resistor is connected to one end of the first capacitor via a switch means, and
One end of a second capacitor disposed coaxially with the first capacitor and insulated from each other is connected to the one end of the first capacitor via the switch means and the first resistor, and the other end is connected to the first end of the second capacitor. The second resistor is connected to the other end of the first capacitor, and a second resistor is connected in parallel between both ends of the second capacitor. The first capacitor is charged with charge supplied from the DC power source, and when the switch means is turned on, the charge charged in the first capacitor is discharged through the first and second resistors and the second capacitor. Then, a pulse is output from both ends of the second resistor.

In one embodiment of the present invention, the first capacitor is composed of a plurality of capacitor units arranged in a cylindrical shape around one axis, and
Each capacitor unit is composed of single capacitors connected in series in the direction of the axis.

In another embodiment of the present invention, the second capacitor is composed of a plurality of capacitor units arranged in a cylindrical shape coaxially with the first capacitor inside the first capacitor, and each capacitor The unit consists of single capacitors connected in series in the direction of the axis.

In yet another embodiment of the present invention, the capacitor units of the first capacitor are interconnected at one end and the other end thereof by a metal plate, respectively.

In a further embodiment of the invention, the switching means comprises a discharge gap and a trigger electrode for initiating a discharge in the discharge gap.

In yet another embodiment of the present invention, the switch means is constituted by a switch that is turned off and on by moving a movable contact into and out of contact with a fixed contact.

(Effects of the Invention) According to the present invention, the first and second resistors and the second capacitor are arranged coaxially with the first capacitor, and the first capacitor is charged. The direction in which the charge discharge current flows from the first capacitor and the direction in which the current flows into the first and second resistors arranged inside the first capacitor and the second capacitor are opposite to each other, and the direction is circular. Since the current flows in a circular pattern, the inductances generated in each current-carrying path are canceled out, and the residual inductance becomes small. As a result, even if the resistance value of the first resistor, which functions as a control resistor, is reduced, high-frequency vibrations will not occur in the output pulse, and the rise of the output pulse can be made faster with high efficiency. .

Further, according to one embodiment and another embodiment of the present invention, since the first and second capacitors are constituted by a plurality of capacitor units in which single capacitors are connected in series, each capacitor unit is A pulse generator having a high withstand voltage and suitable for generating high voltage pulses can be obtained. Furthermore, according to the above embodiment, the capacitance of the single capacitor is selected and the first
And the capacitance of the second capacitor can be set to a desired value.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 1, a first cylindrical insulator 11 made of resin molded into a cylindrical shape has a circular first metal plate 12 coaxial with the first cylindrical insulator 11 on one end surface thereof. A second metal plate 1 having a substantially square shape is attached to the other end surface of the second metal plate 1 by a pin 13.
4 is a pin 13 coaxially with the first cylindrical insulator 11.
Fixed by Both the first metal plate 12 and the second metal plate 14 are made of a highly conductive metal such as copper or brass. The first metal plate 12 has a diameter slightly larger than the outer diameter of the first cylindrical insulator 11 . Further, the length of each side of the second metal plate 14 is the same as that of the first cylindrical insulator 1.
It is larger than the outer diameter of 1.

On the outer peripheral surface of the first cylindrical insulator 11, a capacitor unit _Co1 formed by connecting four capacitors _CM in series is arranged in the axial direction of the first cylindrical insulator 11. This capacitor unit Co ₁
, one terminal 15 is the first terminal of the first metal plate 12.
The other terminal 16 is soldered to the protrusion 12a that protrudes outward from the end surface of the cylindrical insulator 11, and the other terminal 16 is
The metal plate 14 is soldered to a protrusion 14 a that protrudes outward from the end surface of the first cylindrical insulator 11 . On the outer peripheral surface of the first cylindrical insulator 11, as shown in FIG _.
is placed. These 8 sets of capacitor units
Co ₁ are connected in parallel to each other to form a cylindrical first capacitor as a whole.

Note that one terminal 15 of each capacitor unit Co ₁ is inserted into the insertion hole 1 formed in the first metal plate 12.
7, it is bent at right angles and soldered to the first metal plate 12. The other terminal 16 of each capacitor unit Co ₁ is also connected in the same manner as above.
It is soldered to the second metal plate 14.

On the other hand, inside the first cylindrical insulator 11,
As shown in FIG. 1, a second cylindrical insulator 21 is fixed coaxially with the first cylindrical insulator 11. As shown in FIG. This second cylindrical insulator 21 has a third metal plate 2 whose one end is housed within the first cylindrical insulator 11.
2 with a pin 13, and the other end is fixed to the second metal plate 14.

A fourth metal plate 23 is arranged between the third metal plate 22 and the first metal plate 12, and this fourth metal plate 2
3 and the third metal plate 22 is a first resistor Rs ₁ consisting of a resistor unit Rs that functions as a braking resistor.
is arranged coaxially with the first cylindrical insulator 11. Each of the resistor units Rs is connected between the fourth metal plate 23 and the third metal plate 22.

Between the third metal plate 22 and the second metal plate 14, a resistance unit R _L1 in which six resistors R _L are connected in series is arranged in the axial direction of the second cylindrical insulator 21. , is connected between the third metal plate 22 and the second metal plate 14. The above resistance unit
R _L1 is a total of 8 sets around the second cylindrical insulator 21,
These eight resistor units R _L1 constitute the second resistor.

Also between the third metal plate 22 and the second metal plate 14 is a capacitor unit _CR1 in which six capacitors _CR are connected in series.
It is arranged outside R _L1 in the axial direction of the second cylindrical insulator 21 and connected between the third metal plate 22 and the second metal plate 14 . A total of eight sets of the capacitor units C _R1 are arranged around the second cylindrical insulator 21, forming a cylindrical second capacitor as a whole. It is preferable for the second capacitor to be configured as closely as possible to the first capacitor for the purpose of canceling out inductance, which will be described later.

Discharge electrodes 31 and 32 are attached to the center of the first metal plate 12 and the fourth metal plate 23 so as to face each other with a gap g therebetween. A trigger electrode (not shown) is arranged near the discharge electrode 32, and a trigger pulse is applied to this trigger electrode from the outside.

On the other hand, a coaxial plug 33 for pulse output is attached to the center of the second metal plate 14, and a center conductor 33a of the coaxial plug 33 is connected to the center of the third metal plate 22 through a conductor 34. be done.

The pulse generator described above with reference to FIGS. 1 and 2 has a circuit configuration as shown in FIG. 3. That is, a total of eight capacitor units Co ₁ are connected in parallel between the first metal plate 12 and the second metal plate 14. In addition, the second metal plate 14
A total of eight resistor units R _L1 are connected in parallel between and the third metal plate 22, and eight capacitor units C _R1 are connected in parallel. Further, a resistance unit Rs ₁ is connected between the third metal plate 22 and the fourth metal plate 23, and discharge electrodes 32 and 31 are connected to the fourth metal plate 23 and the first metal plate 12, respectively. .

In such a configuration, when the second metal plate 14 is connected to the ground and a DC voltage is applied from the charging terminal 35 through the charging resistor Rc to the first metal plate 12, the capacitor unit _Co1 is charged with electric charge.

After the charging to the capacitor unit Co ₁ is completed, when a trigger pulse is applied to the trigger terminal 36, the charges charged in the capacitor unit Co ₁ are discharged, and a discharge current ip flows from each capacitor unit Co ₁ to the first metal plate 12. flows through the center of the resistor unit Rs ₁ . After this, the above discharge current ip
is shunted to each resistor unit R _L1 and capacitor unit _CR1 at the third metal plate 22, and currents ir and iq flow through each resistor unit R _L1 and capacitor unit _CR1 , respectively.

The direction in which the discharge current ip flows out from _each capacitor unit Co ₁ and the direction of _the currents ir and _iq are opposite to each other. Since the unit C _R1 is arranged coaxially and the currents ir and iq flow concentrically with respect to the above current ip, the inductance generated in the flow path of the current ip and the inductance generated in the flow path of the currents ir and iq cancel each other out. We share each other. As a result, the residual inductance of the pulse generator shown in FIG. 1 is reduced.
Therefore, by reducing the resistance value of the resistor unit Rs ₁ within a range where high frequency vibrations do not occur, it is possible to obtain high quality pulses with a fast rise and no high frequency vibrations from the coaxial plug 33.

In the above embodiment, the residual inductance L is approximately
30nH, less than 1/100 of the conventional pulse generator, and the rise of the output pulse is 1μs with a conventional pulse generator.
What used to be 1.5 μs, we were able to obtain a value of about 100 ns, which is less than 1/10 of the time.

In the above embodiment, eight sets of capacitor units Co ₁ , C _R1 and resistor units Rs ₁ , R _L1 are used.
Co ₁ , _CR1, etc. are not limited to eight pairs.

Also, the number of capacitors C _M and _CR that make up each capacitor unit Co ₁ and C _R1 , and the number of each resistor unit.
The numbers of resistors Rs and R _L that constitute Rs ₁ and R _L1 are also arbitrary.

Furthermore, individual cylindrical capacitors may be used as the first and second capacitors.

Furthermore, instead of the discharge electrodes 31 and 32, a switch can be used to start discharging the capacitor unit _Co1 .

[Brief explanation of drawings]

1 and 2 are a partially sectional front view and a partially cutaway side view of a pulse generator according to the present invention, respectively, and FIG. 3 is an equivalent circuit diagram of the pulse generator of FIGS. 1 and 2, and FIG. Figure 4 is a circuit diagram of a conventional pulse generator, Figure 5 is an equivalent circuit diagram of the pulse generator in Figure 4 when pulses are generated taking into account residual inductance, and Figures 6 and 7 are respectively showing the braking resistance. FIG. 5 is an explanatory diagram showing changes in the pulse waveform output from the pulse generator of FIG. 4 according to FIG. DESCRIPTION OF SYMBOLS 11... First cylindrical insulator, 12... First metal plate, 14... Second metal plate, 21... Second cylindrical insulator, 22... Third metal plate, 23... Fourth metal Plate, Co ₁ , C _R1 ... Capacitor unit, Rs ₁ ,
R _L1 ...Resistance unit.

Claims (1)

[Scope of Claims] 1. A first capacitor having a cylindrical structure with one end connected to a DC power supply and the other end grounded, a switch means for temporarily discharging the electric charge of the first capacitor, and a switch means for temporarily discharging the electric charge of the first capacitor. a first resistor connected to one end of the first capacitor via the switch means; a first resistor disposed coaxially with the first capacitor and insulated from each other; 1st
a cylindrical second capacitor whose other end is connected to the other end of the first capacitor;
A pulse generator comprising: a capacitor; and a second resistor arranged in parallel between both ends of the second capacitor. 2. The pulse generator according to claim 1, wherein the first capacitor is composed of a plurality of capacitor units. 3. The plurality of capacitor units are arranged in a cylindrical shape around one axis, and each capacitor unit is constituted by a single capacitor connected in series in the direction of the axis. The pulse generator according to range 2. 4. Claim 1, wherein the second capacitor is composed of a plurality of capacitor units, and is arranged coaxially with the first capacitor inside the first capacitor. The pulse generator described. 5. Claim 4, characterized in that each of the plurality of capacitor units constituting the second capacitor is composed of a single capacitor connected in series in the axial direction of the first capacitor.
Pulse generator as described in section. 6. Any one of claims 1 to 3, wherein each of the capacitor units of the first capacitor has one end and the other end connected to each other by a metal plate, respectively. 1. The pulse generator described in 1. 7. Claim 1, characterized in that the first resistor is composed of a plurality of resistor units, and is arranged coaxially with the first capacitor inside the first capacitor. The pulse generator described. 8. Claim 1, wherein the second resistor is composed of a plurality of resistor units, and is arranged coaxially with the first capacitor inside the first capacitor. The pulse generator described. 9. The pulse generator according to claim 1, wherein said switching means comprises a discharge gap and a trigger electrode for starting discharge in said discharge gap. 10. The pulse generator according to claim 1, wherein the switch means is a switch that is turned off and on by moving a movable contact into and out of contact with a fixed contact.