SU790201A1 - Voltage pulse limiter - Google Patents

Description

one

The invention relates to radio. and can be used to limit the amplitude of voltage pulses. Mohset pulse limiter is most efficiently used in cases when it is necessary to galvanically isolate input and output circuits, in particular, in equipment designed for use in plasma installations, accelerators, and the like.

Voltage pulse limiters 1-2 are known,

These limiters either do not provide galvanic isolation of the input and output circuits, or require an additional power source; in addition, their circuits differ in relative complexity.

The closest technical solution to this invention is a voltage pulse limiter containing a resistor connected in series with the load, in parallel with which a transistor is connected, between the base and emitter of which threshold element 3 is turned on,

The disadvantage of a known voltage pulse limiter is the deterioration of its speed when

relatively high values of the limiting level (tens of volts), since Zener diodes, 5 having large capacitance values (more than 100 pF) between the anode and cathode, are used as the threshold element.

The purpose of the invention is to increase

To the level of limitation while maintaining the speed of the device.

This goal is achieved by introducing a transformer with two connected according to and magnetos jc windings, the resistor, transistor collector, the threshold element and the beginning of the first winding of the transformer are interconnected, the end of this winding is connected to

2Q emitter of the transistor, and the threshold element through the beginning of the second winding is connected to the base of the transistor.

Such a voltage pulse limiter practically allows an increase in the level of pulse limiting by an order of magnitude without losing speed. FIG. 1 shows the principal; electrical circuit of the device; in fig. 2 - electrical circuit

3Q one of the options for implementation.

The voltage pulse limiter comprises a resistor 1, a transistor 2 in parallel with which transformer primary winding 3 is connected, the other winding 4 of which is connected between the base of transistor 2 and threshold element 5. The device b load is connected to the third secondary winding 7 of the transformer. The device input is terminals 8 and 9.

The device works as follows.

If positive impulses are supplied to the input of the device, the amplitude of which exceeds the limiting level, then on the collector of the transit & 2 torus the amplitude of the limited pulse Ujt is approximately equal to

 U, "UB, KU, .U,;, ti)

fall

Ugg + on open transistor 2 and threshold. element 5, and

/ 2 Ml

-trans-h 1 formations between the secondary and primary windings of the transformer. equation (1) for (

LV (

pe

Then

Thus, choosing K less than unity, it is possible to obtain a level of restriction greater than in the known device, as can be seen from equation (2).

The device, made according to the invention, has

relatively high speed does not require power sources and provides galvanic isolation between input and output circuits.

Serial transformer MIT-10 (, 5, Ki Nk / j / v /, l) is used as a transformer. The maximum amplitude of the input pulses is 300 V. The amplitude of the limited pulses at the output of the third markup is 6 V. The proper rise time of the pulses is less than 50 ns.

Claims (3)

1. US Patent 3,705,418, cl. 307-237, pub. 1972. 2. USSR author's certificate 266829, cl. H 03 K 5/08, 1968. 3. Japanese patent number 25136, cl. 98 (5) A 14, published. 1969.