SU577628A1 - Adjustable push-pull inverter - Google Patents

Description

I

The invention relates to a conversion technique and can be used to obtain a pulse-controlled voltage.

 Devices are known for carrying out voltage regulation 1, 2. However, using such devices, a wide range of regulation is not possible. In addition, they are complex and not reliable enough. The closest to the proposed device is an adjustable push-pull inverter containing an output transformer connected to the input terminals, the transistors connected to the primary windings, and their bases are connected via diodes to the control terminals signals and associated with two control key elements H,

These key elements are included in the inverter positive feedback circuit. With alternate control from the master oscillator, bipolar pulses of variable frequency and adjustable duty cycle are taken from the output of the inverter.

The disadvantage of this device is the impossibility of a wide range of regulation. Also, since the vein

The new elements are included in the trans-chi; tori bases; the reliability of the entire device decreases (the regime with a dangling base).

The purpose of the invention is to increase confidence and expand the range of regulation.

This is achieved by the fact that the controllable key elements form a trigger connected to the input pins / and its control inputs are connected to additional windings and transformers, and the outputs through rheistors to control transitions corresponding to

related transistors.

The drawing shows a diagram of a 1-shot push-pull inverter.

The inverter is made on the basis of a magnetotransistor multivibrator 1 on

transistors 2.3 and transformer 4, having two primary windings 5.6, two windings 7.8 positive feedback, two additional windings 9.10 and output winding I. To the base of the transistors, control pulses are sent through diodes 2.13 . In the cream of this, the inverter contains a trigger 14 on controlled key elements. (Thyristors) 15,16, resistors 17,18 and con

densator 19, and the anodes thyristor

connected through resistors 20, 21, with the bases of transistors 2.3 so that opposite ends of the feedback winding 7 or 8 and the additional winding 9 or 10 are connected to the base of the transistor and to the control electrode of the thyristor connected to it.

The scheme works as follows.

When supply voltage is applied and control pulses are absent, the inverter starts to work in autoscale mode. Suppose that it opens (transistor 2, then the field pkocTb of the voltage on the windings of transformer 4 corresponds to the indicated circuit

The thyristor 15 is turned on, and unlocking voltage is applied to the base of transistor 2 through resistor 20. When a positive control pulse arrives at the bases of transistors 2.3 through diodes 12, 13, transistor 2 closes and remains in this position for a time equal to the duration of the synchronization pulse. At the end of the control pulse, transistor 2 opens again, since at its base there is an unlocking voltage.

When the next control pulse arrives, the processes described are repeated.

The operating point of the transformer then moves along a hysteresis loop. When a certain number of control pulses arrive, the core of the transformer 4 becomes saturated and the inverter switches, i.e. transistor 2 is closed and transistor 3 is removed. The polarity of the voltage on the windings of the transformer 4 becomes opposite to that indicated in the diagram.

Suppose that the thyristor 16 is now turned on, and the unlocking voltage is applied to the base of the transistor 3.

When the control pulses arrive, the transistor 3 will switch in the same way as transistor 2 until the transformer 4 becomes saturated and the next inverter is switched.

When adjusting the duration of control pulses arriving at a constant frequency, the number of pulses and their duration in the half-period of the output voltage, as well as its frequency, change. Moreover, the total volt-second pulse area in the half-period of the output voltage Bcet remains the same.

The output frequency range of the inverter is bounded above by the corresponding frequency of the inverter, and from below by the recovery time of the control properties of the thyristors, and the output voltage control range varies from zero to a value determined by the parameters of the secondary winding of the transformer.

Based on the inverter, an adjustable DC source can be created, the frequency of the smoothing filter being determined by the frequency of the control voltage.

Claims (3)

Invention Formula An adjustable push-pull inverter, containing an output transformer connected to the input pins, to which transistors are connected to the primary windings, and their bases are connected via diodes to the pins for control signals and connected to two control elements, one with in order to increase the reliability and increase the control range, the controlled key elements form a trigger connected to the input terminals, and its control inputs are connected to the additional windings of the transformer, and the outputs through resistors - to the control transitions of the corresponding transistors. Sources of information taken into account in the examination: 1, Copyright Certificate of the USSR 369668, cl. H 02 R 13/16, 1970, 2; Mochalov V.D. Magnetic Integrating Circuits of Computers and Automatics, M., Energie, 1968, p. 18, Fig. 32. 3. US patent number 3351840, kl.321-45, 1967.