SU767953A1 - Two-channel pulse former for electric drive control system - Google Patents

Description

(54) TWO-CHANNEL PULSE FORMER FOR ELECTRIC DRIVE CONTROLS

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A two-channel pulse shaper for electric drive control devices is known, containing in each channel a transistor keystone pulse shaper and a key transistor amplifier, the output of which through a Zener diode is connected to the base of a transistor common to two channels of a blocking generator, the output winding of the blocking transformer through a diode and a resistor is connected to device output 1.

The disadvantage of a two-channel pulse generator is the low reliability of its operation.

The purpose of the invention is to increase the work of the former.

The goal is achieved in that a two-channel pulse shaper for electric drive control devices contains each channel. A transistor shaper of trapezoidal pulses and a key transistor amplifier, the output of which through a Zener diode is connected to the base of a blocking oscillator, output blocking transformer which through the diode and the resistor is connected to the output

device, introduced two additional diode connected between the outputs of the transistor shapers of trapezoidal pulses and the inputs of key amplifiers, and a resistor connected between the total width of the transistor shapers of trapezoidal pulses and the total thickness of the key amplifiers.

The drawing shows the structural electrical circuit of a two-channel pulse generator for drive control devices.

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In each channel of a two-channel pulse conditioner, transistor drivers 1, 2 of trapezoidal pulses contain transistors 3 and 4, resistors 5 and 6, 7 and 8, zener diodes 9 and 10, capacitors 11 and 12. The outputs of drivers 1 and 2 of trapezoidal pulses through the corresponding separation diodes 13 and 14 are connected to the inputs of key transistor amplifiers 15 and 16 on transistors 17 and 18, resistors 19 and 20, 21 and 22, restrictive diodes 23 and 24. The outputs of key transistor amplifiers 15 and 16 are connected to the input of a common for two channels blocking-gene rator 25 with a transistor 26, a blocking transformer 27 with an input 28 and output 29 and 30 winding MI, a separation diode 31, resistors 32 and 33, a resistor 34, a diode 35 and a capacitor 36. The outputs of the key transistor amplifiers 15 and 16 are connected via zener diodes 37 and 38 to the blocking generator 25. The two-channel pulse shaper also contains a variable resistor 39, resistors 40 and 41, input buses 42 and 43, output tires 44 and 45, buses 46, 47, 48, 49, 50. The common entry point is indicated by 51 .

The shaper works as follows.

A sinusoidal voltage is applied to the input terminals 42, 43, synchronized with the frequency of the mains supply. Since the circuit is symmetric, we will describe the signal passing through the upper section of the circuit - for a positive half-wave. - The trapezoidal pulse width is determined by the bias voltage common to both channels supplied to buses 46, 47 by the polarity indicated in the diagram. Trapezoidal pulses drive the shaper 1 and trapezoidal pulses. A sawtooth voltage is formed during periods of time when transistor 3 is closed, i.e., during the absence of a trapezoidal pulse. The reliable locking of the transistor 3 at the moment when the trapezoidal pulses are absent is carried out by the negative bias applied through the resistor 5. The parameters of the resistor 6 and the capacitor 11 are chosen so that the voltage on the capacitor 11 increases linearly.

In the initial state, the transistor 18 of the key amplifier is biased by a bias current, which is determined by the magnitude of the resistor 19. The sawtooth voltage is blocking for the transistor 18. Once this voltage exceeds the control voltage that the regulated resistor 39 is applied to, the polarity in the drawing, transistors 18 are closed. Thus, the moment of transition of the transistors 18 from the saturation mode to the cutoff mode is determined by the magnitude of the control voltage and can be controlled in phase in the range from 0 to 180 ° relative to the trailing edge of the rectangular pulse. Diodes 24 are needed to limit the positive voltage on the bases of the transistors 18. Diodes 13 (14) prevent short-circuiting from the source of control voltage through saturated transistors 3 (4) or discharged capacitors 11 (12).

The rectangular pulses taken from the collectors of the transistors 18 (17), shifted in phase by 180 °, through the zener diodes 37 control the operation of the blocking generator, 25, operating in standby mode. The zener diode 37 excludes the supply of reverse voltage to the transistor 18, and also stabilizes the voltage from the transistor 18 to the transistor 26, thereby ensuring the receipt of 25 pulses of the amplitude strictly equal to the output of the 44, 45 blocking generator. At the moment of the absence of a rectangular pulse from transistor 18, transistor 26 is locked by a positive bias voltage, resistor 32 is adjusted for the reverse current of the base.

The blocking generator is started by the negative pulse, taken from the transistor 18. The operation time of the blocking generator is determined by the width of the negative rectangular pulse.

A burst of pulses or single pulses removed from the secondary winding of a pulsed transformer is fed through output diodes 44, 45 through diode 35 to an electric drive control device.

The other half of the circuit works similarly.

The shaper allows to obtain single pulses or pulse packets that are strictly equal in amplitude, it is stable in operation, reliable and does not require maintenance during operation.

Claims (1)

Invention Formula Dual-channel pulse shaper for electric drive control devices containing a transistor keystone pulse driver in each channel and a key transistor amplifier, the output of which through a Zener diode is connected to the base of a transistor common to two channels of a blocking generator, the output winding of the blocking transformer through a diode and a resistor is connected to the output of the device , characterized in that, in order to increase the reliability of operation, two additional diodes are inserted in it, connected between the outputs and transistor formers of trapezoidal pulses and inputs of key amplifiers, and a resistor connected between a common busbar of transistor formers of keystone impulses and a total thickness of key amplifiers. Sources of information taken into account in the examination 1. Navy. “Transport, 1975, No. 11, p. 49 (prototype). I1 | -} C S fJO r "J- I -rH4-er 5