RU2785411C1 - Rectangular voltage pulse generator - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to generators of mostly nanosecond and microsecond rectangular voltage pulses of a high amplitude, without subsequent oscillations, which can be used for tests of electrical insulation materials, as well as in pulse power supply systems of such loads as solid-state laser pumping lamps, laser diodes, magnetrons, high-voltage test benches. The invention uses a uniform artificial forming line, a consistent load, and a system for adjustment of a pulse shape, consisting of sequentially connected adjusting capacity and resistance, and a forming (line) with distributed parameters, connected in parallel to them, having wave resistance equal to load resistance and an electrical length equal to half the front duration of a pulse obtained without the use of this forming line.

EFFECT: obtainment of single voltage pulses of a rectangular shape.

1 cl, 1 dwg

Description

In impulse technology, generators of impulse voltages with direct discharge of a capacitor or those made according to the Arkadiev-Marx scheme [1] have found wide application. In the voltage pulse generation mode, the oscillator is a series circuit of capacitors forming a shock capacitance C _r , which, being connected to a resistive load R, is discharged with a characteristic time RC _r , so that the shape of the pulse on the load, if the parasitic inductance and capacitance are sufficiently small, has view

где n - число ступеней генератора, V₀ - напряжение заряда каждой ступени.

where n is the number of generator steps, V ₀ is the charge voltage of each step.

The exponential shape of the voltage pulse is not always acceptable, and therefore, to obtain a rectangular pulse, circuits for correcting the shape of the voltage pulse are used.

Known pulse voltage generator, in which the correction of the shape of the top of the pulse occurs due to the discharge of the correction capacitance through the resistor [2]. The disadvantage of such a generator is the pronounced uneven shape of the pulse top. This is due to the fact that the initial section of the exponentially decreasing generator voltage subjected to correction is almost linear in nature, and the correction voltage changes non-linearly over time, since it represents a full exponential discharge of the correction capacitance through the resistor.

Rectangular voltage pulse generators are known, in which the corrective circuit consists of at least one capacitor shunted by an inductance, which are switched by a separate spark gap [3], [4]. The disadvantage of such devices is the complexity of the electrical circuit, caused by the need to have an additional switch and control unit for synchronous control of the spark gap.

Also in pulsed technology, pulsed voltage generators containing homogeneous artificial lines [6] with a trapezoidal pulse shape at a matched load have found wide application. One of the important parameters of the pulse is the shape of the pulse top and its front. To obtain voltage pulses with a steep leading edge and a flat top, corrective chains are used [5], [6]. Nevertheless, these corrective circuits do not allow obtaining an impulse on a matched load, which is close in shape to a rectangular one in the front.

In the nanosecond range of durations, an approximation to the desired pulse shape can be achieved by using forming lines with distributed parameters. However, as the pulse duration increases, the use of such lines becomes difficult due to the need for a corresponding increase in their length.

According to the criterion of minimum sufficiency, the closest is the generator according to patent RU 2102834.

The advantage of the claimed generator in comparison with the known ones is the production of single trapezoidal voltage pulses of micro and nanosecond durations on a matched load with a shape that is close to rectangular in the front part when using a relatively simple electrical circuit.

This is achieved in this invention using a circuit containing a homogeneous artificial forming line, a matched load, a switch, a source of charging voltage, a pulse shape correction system, characterized in that the correction system contains series-connected corrective capacitance and resistance, and a forming line connected in parallel to them. with distributed parameters, having a wave impedance equal to the load resistance, and an electrical length equal to half the duration of the front of the pulse obtained without the use of this forming line.

Figure 1 shows the circuit diagram of the pulse generator.

The generator works as follows. A homogeneous artificial forming line (highlighted by a dotted line in the figure) (5) is charged through the resistance (2) from the charging voltage source (1). When the controlled switch (3) is closed, the homogeneous artificial forming line (5) is discharged to the load (4). The decrease in the duration of the front of the pulse occurs due to the discharge of the line also to the series-connected corrective capacitance (6) and resistance (7) and the forming line connected in parallel to them with distributed parameters (8).

The effectiveness and efficiency of using the proposed generator is as follows. The described design of the generator makes it possible to obtain single voltage pulses of micro and nanosecond durations of a rectangular shape using a relatively simple electrical circuit and can be applied in practice to test electrical insulating materials and electrical and radio products for pulsed electrical strength, as well as in pulsed power systems for such loads as pump lamps solid state lasers, laser diodes, magnetrons, high voltage test benches.

Sources of information

1. Month G.A. Pulse energy and electronics. - M.: Nauka, 2004.

2. Patent RU 2012129 C1. High voltage pulse generator.

3. Patent RU 2102834 C1. Rectangular high voltage pulse generator.

4. A.S. USSR SU 1465949 A2. High voltage pulse generator.

5. Evtyanov S., Redkin G.E. Pulse modulators with an artificial line. / M., Soviet radio, 1973.

6. Opre V. Generators of rectangular current pulses based on homogeneous artificial lines. // Power electronics, 2008, No. 1. pp.56-61.

Claims (1)

A generator of rectangular voltage pulses, containing a uniform artificial forming line, a matched load, a switch, a charging voltage source, a pulse shape correction system, characterized in that the correction system contains series-connected corrective capacitance and resistance and a forming line connected in parallel to them with distributed parameters, having wave resistance equal to the load resistance, and an electrical length equal to half the duration of the front of the pulse obtained without the use of this forming line.

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