SU1476597A1 - High-voltage pulse shaper - Google Patents

Abstract

The invention relates to a pulse technique and can be used as a source of pulses for excitation, for example ultrasonic transducers, etc. The purpose of the invention — extending the functionality — is achieved by obtaining single pulses or a series of unipolar short pulses of a given amplitude. The device contains an avalanche transistor 1 with a load 2 in the emitter circuit of transistor 1, a resistor 3, a storage capacitor 4 in the collector circuit of transistor 1, a diode 5, a common bus 6 and an inductor 7 connected to the collector of transistor 1. If in coil 7 for synchronization a pulse will accumulate so much energy that it will be enough for several charges of a capacitor before the breakdown voltage of the avalanche transistor 1, then a series of several pulses will be formed on the load 2, the repetition period of which will be about four and the period of the oscillation circuit consisting of the inductor coil 7 and the capacitor 4. 1 yl.

Description

one

The invention relates to a pulse technique and can be used as a source of pulses for exciting, for example, ultrasonic piezo transducers, etc.

The purpose of the invention is to expand the functionality by obtaining single or a series of unipolar short pulses of a given amplitude.

The drawing is a schematic of the electrical circuit of the driver.

The shaper contains an avalanche transistor 1 with a load 2 in the emitter circuit of transistor 1, a resistor 3

.connected to the base of transistor 1, a storage capacitor 4 in the collector circuit of transistor 1, a diode 5 whose cathode is connected to the common bus 6, and the anode is connected to the emitter of transistor 1, and an inductance coil 7 connected to the collector of transistor 1,

The pulse shaper operates as follows.

A rectangular positive pulse through the resistor 3 opens the transistor 1 and during this synchronizing pulse in the inductor 7 the current increases, i.e. accumulates energy. At the end

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A positive square synchronizing pulse, the transistor closes and the energy stored in the coil 7 charges the storage capacitor 4 to a high voltage. As the voltage on the capacitor 4 rises, a moment comes when this voltage reaches the voltage of the avalanche transistor 1 and it breaks through. At this point in time, a short pulse of positive polarity is released at load 2. Diode 5 in this circuit performs two functions. The first function is to shunt the load 2 during a positive square clock pulse, which has a much longer duration and a much smaller amplitude than the generated pulse on load 2 after the transistor 1 has been broken. Without this diode, the circuit on one transistor performs The functions of the emitter follower and, if the amplitude of the synchronizing pulse is not much less than the voltage of the power source, the current through the coil 1 practically does not flow and there is no accumulation of energy. The second function is the shortening of the cut of the formed pulse. This happens as follows. The direct impulse resistance of diode 5 at the first moment of time is large, so the entire collector current flows through load 2 and resistor 3. At the same time, most of the current flows through load 2. As time passes, the direct impulse resistance of diode 5 decreases in size, as a result the load current ratio decreases as the shunt effect of diode 5 begins.

After the formation of a pulse at load 2, the avalanche transistor 1 for-

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The energy remaining in the circuit consisting of the coil 7 and the capacitor 4 begins to oscillate. We obtain a pulse on the collector of transistor 1. However, at the end of it, an oscillatory after-sound is observed. To eliminate the after-sounding in series with the inductor 7, a diode 8 is connected. If the inductor 7 accumulates so much energy during a synchronizing pulse that it lasts for several capacitor charges up to the avalanche breakdown voltage 1, a series of several pulses, the repetition period of which is about a quarter of the oscillation period of the circuit from the inductor 7 and the capacitor 4.

Claims (1)

Invention Formula A high-voltage pulse shaper comprising a transistor whose collector is connected to the power supply bus and storage capacitor plate, load, diode, transistor base through an inductance coil, the base of the transistor is connected to the input source, in order to expand its functionality by obtaining a single or series unipolar short pulses of a given amplitude, an avalanche transistor is used as a transistor, the emitter of which is through parallel-connected loads and a diode connected to the common bus, wherein the diode is connected in the forward direction with respect to the power source, the second plate of the storage capacitor connected to the common bus. I