JPS5870628A - Pulse generating circuit - Google Patents

Abstract

PURPOSE:To prevent arc-through, by avoiding charging to a pulse forming circuit until a switching element is completely turned off after it turns on. CONSTITUTION:When a control trigger signal 20 is inputted to a main trigger circuit 21 and a trigger delay circuit 22, a main trigger signal is outputted from the main trigger circuit 21 to trigger a main switching element 19. The trigger delay circuit 22 outputs a control trigger signal with a delay ad drives a control trigger circuit 23. Thus, a charging trigger signal is outputted from the control trigger circuit 23 to the main trigger signal after a specified delay time. A switching element 13 for charging turns on with the charging trigger signal. Since a stable inverse biase can be given to the main swithcing element 19 until turning-off, the arc-through of the main switching element can be suppressed.

Description

[Detailed description of the invention] The present invention relates to a Rheintaig Noculus generator.

FIG. 1 is a connection diagram of a conventionally used line pulse generator. Reference numeral 1 in FIG. 1 denotes a charging impedance element, for example, a choke coil is used, and charges the loop forming circuit 2 to a voltage approximately twice the power supply voltage.

Further, 3 is a discharge switching element, for example, a thyratron is used. This discharge switching element 3 is ignited by a control trigger signal 5 inputted via a main trigger circuit 4. By igniting this discharge switching element 3,...
A Norse voltage determined by the voltage is generated across the load 6. Note that 7 is a DC power supply.

FIG. 2 shows the operating waveforms of each part in FIG.
Reference numeral 9 indicates an output pulse waveform applied to the load 6, and reference numeral 10 indicates a control trigger signal.

Here, once the thyratron that can be used as the discharge switching element 3 is turned on, it remains on for a period (deionization time) until the hydrogen gas ions in the tube are neutralized. Furthermore, when a thyristor is used as the discharge switching element 3, the on state is similarly maintained for a period (turn-off time) until excess carriers inside the junction disappear.

Therefore, in order to repeatedly switch the line type Grush generator shown in Fig. 1, it is necessary to add a sufficient reverse electric ratio to the discharge switching element 3, shorten the turn-off time, and completely It is necessary to operate so that no forward voltage is applied until the discharge switching element 3 is turned off.

The application of the reverse voltage is achieved by making the load impedance lower than the characteristic impedance of the pulse shaping circuit 2, and by using the reflected reverse voltage generated in the pulse shaping circuit 2.

However, with this method, when the number of repetitive shaving waves is high or the load impedance changes, it is difficult to maintain sufficient reverse bias application time to the discharge switching element 3, and the arcing phenomenon of the discharge switching element 3 is difficult to maintain. Easy to occur.

This invention was made in order to eliminate the above-mentioned conventional drawbacks, and the main switching element is prevented from starting charging to the noggles molding circuit until it is completely turned off after the main switching element is turned on. It is an object of the present invention to provide a pulse generation circuit that can prevent arcing of elements.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the main pulse generation circuit of the present invention will be described with reference to the drawings. FIG. 3 is a circuit diagram showing one embodiment of the invention. In FIG. ), a charging switching element 13 (for example, a thyristor is used as the switching element with a control electrode), a coil 14, a pulse shaping circuit 15 made up of a coil and a capacitor, and a load 16. Connected to negative pole. This negative electrode is grounded.

A capacitor 17 and a resistor 18 are connected in parallel to the charging switching element 13.
A series circuit with is connected. Further, a main switching element 19 is connected between the connection point between the coil 14 and the pulse shaping circuit 15 and the ground.

There is. As the main switching element 19, for example, a thyratron is used.

On the other hand, 20 is a control trigger signal, and this control trigger signal 20 is input to a main trigger circuit 21 and a trigger delay circuit 22, and the output of the circuit 21 is sent to the main switching element 19. Trigger delay circuit 22
The output is sent to the cape trigger circuit 23. The output of the control trigger circuit 23 is the switching element 13 for charging.
It is designed to be sent to

Next, the operation of the cell generation circuit of the present invention constructed as described above will be explained with reference to the waveform diagram of FIG. FIG. 4(a) d shows the charging voltage charged by the charging impedance element 12, FIG. 4(b) shows the main trigger signal output from the main/trigger circuit 21, and FIG.
) shows a charging trigger signal output from the control trigger circuit 23, and further, FIG. 4(d) shows an output signal applied to the load 16.

Now, when the control trigger signal 20 is input to the main trigger circuit '21 and the trigger delay circuit 22, the main trigger signal is output from the main trigger circuit 21 as shown in FIG. 4(b), and the main switching element 19 fires. In addition, the trigger delay circuit 2
2 outputs the control trigger signal 20 with a predetermined time delay;
The control trigger circuit 23 is driven. As a result, the charging trigger output from the control trigger circuit 23 is set to a predetermined value with respect to the signal (2) (Fig. 4 (e)) Fi and the main trigger signal (Fig. 4 (b)) output from the main trigger circuit w621. The output is delayed by a delay time (Td). As a result, charging switching element 1
3 is controlled behind the main switching element J9 by a delay time Td.

When the charging switching element 1.3 is turned on by the output of the control trigger circuit 23, that is, the charging trigger signal, the capacitor of the Cruz shaping circuit 15 resonates with the charging impedance element 12, as shown in FIG. like,
is charged to twice the power supply voltage, but charging switching element 1
Since 3 is a unidirectional switch, this charging voltage is maintained at the peak value of the charging voltage, which is 1\.

Here, when the main switching element 19 is turned on by the output of the main trigger circuit 21, that is, the trigger signal, the electrostatic energy stored in the pulse forming circuit 15 is discharged in the shape of a pulse, and the fourth pulse is applied to both ends of the load 16. As shown in figure (d), a malus-like voltage is generated.

Moreover, the main switching element 19 has a deionization time T after turn-on.
However, if the delay time of the trigger delay circuit 22 is set to be longer than this deionization time Ti, the main switching element 19 will be completely turned off when the charging circuit starts charging. It is possible to prevent arcing. The capacitor 17, the resistor 18, and the coil 14 prevent the charging switching element 13 from firing due to the voltage change rate (du/at) when the main switching element 19 is turned on. Set the following conditions.

Here, R is the resistance value of resistor 18 is the inductance of coil 14 C is the capacitance of capacitor 17 It is.

As described above, according to the pulse generating circuit of the present invention, the charging switching element is inserted between the charging impedance element and the Norms shaping circuit, and the firing timing of the charging switching element is controlled by the main switching element. Since the pulse shaping circuit does not start charging after the main switching element is turned on until it is completely turned off, it is possible to stably apply a reverse bias voltage to the main switching element. This makes it possible to suppress the arcing phenomenon of the main switching element.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of a conventional line type self-generator.
Figure 2 is a waveform diagram of the signals of each part of the line type pulse generator shown in Figure 1, Figure 3 is a circuit diagram showing an embodiment of the pulse generator of the present invention, and Figure g4 (a). or Figure 4 (d
) are each of this invention! 3 is a signal waveform diagram of each part of the pulse generation circuit. FIG. 12... Charging impedance element, 13... Charging switching element, 14... Coil, 15... Mars shaping circuit, 16... Load, 17... Capacitor, 18
...Resistance, 19...Main switching element, 20...Control 1
21... Main trigger circuit, 22... Trigger delay circuit, 23... Control trigger circuit. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2

Claims (1)

[Claims] A charging impedance element to which a power supply voltage is applied, a Nors forming circuit that resonates with this charging impedance element and being charged to a voltage higher than the power supply voltage, and a closed circuit together with this Norss shaping circuit and a load. a main switching element which, when turned on in response to a control trigger signal, discharges the charging energy stored in the pulse shaping circuit in a pulse shape to generate a spiral voltage in the load; and the charging impedance. Motoko and NoJ? a charging switching element inserted between the loop shaping circuit and turning on after a predetermined time delay after the main switching element is turned on to transmit charging energy of the charging impedance element to the loop shaping circuit; Trigger means for triggering the charging switching element with a delay time longer than the turn-on and turn-off time of the main switching element from the arrival of the trigger signal. Lux generation circuit.