SU819943A1 - Sigh-alternating pulse shaper - Google Patents

Description

(54) FORMING FAMILIAR PULSES

one

This invention relates to radio electronics and can be used in automatic control devices on semiconductor elements.

A known shaper of alternating pulses contains a source of direct voltage and four transistors connected by a bridge circuit with a saturable transformer 1.

To control semiconductor elements operating in a key mode, it is necessary to have a lisch signal for a time equal to the time they are locked or locked. At the rest of the time, after switching the semiconductor element during the half-period, the power of the control device is not used.

The disadvantage of this former is that it does not provide the necessary pause after the arrival of rectangular control pulses of alternating polarity, which is a necessary condition for controlling semiconductor elements.

The closest technical solution to the invention is a shaper of alternating pulses containing a current limiter connected in series with the primary winding of a saturable transformer, a transition transformer, backflating circuits including diodes and three diodes and an alternating voltage source 2.

This disadvantage is due to the fact that at the time of the regenerative process there is a sharp increase in the current consumption from the input source of alternating voltage, which, in turn, leads to a violation of stability and reliability of operation.

The aim of the invention is to increase the stability and reduce the power consumption of the alternating voltage.

Claims (3)

The goal is achieved by the fact that a known shaper containing a current limiter connected in series with the primary winding of the saturating transformer, a transition transformer of the backflating circuit, including diodes and transistors, a source of alternating voltage, and two additional windings transition transformer. The primary winding of the saturable transformer is made with an average output. The current limiter is made on transistors sub-differential circuit. The first limit transistor is connected by a collector to the beginning of the primary winding of the saturating transformer, and the basic winding of the transistor Q includes a secondary winding of the saturable Q transformer in parallel with a base resistor and an additional winding of the transition transformer with a base capacitor. These windings are interconnected according to: the positive terminal of the voltage source is connected to the emitters of the transistors, and the negative terminal is connected to the middle output of the primary winding, to which the emitters of the backslip circuits are also connected, and the diodes of these circuits are connected: one to the beginning, and the other, towards the end of the primary winding of the saturating transformer at the moment of formation of the falling front. The drawing shows the principle electric} scheme of the shaper of alternating pulses. The former contains sources of alternating and direct voltage, current limiter 1 connected in series with a saturable transformer. 2. The current limiter is made on transistors in a differential circuit and contains transistors 3 and 4. The base of transistor 3 through the base resistor 5 is connected to the end of the winding 6 of the transformer 2 and through the base capacitor 7 to the end of the winding 8 of the transition transformer 9. The base of the transistor 4 through the base resistor 10 is connected to the beginning of the winding 11 of the transformer 2 and through the base capacitor 12 to the beginning of the winding 13 of the transformer 9. The primary semi-winding 14 of the transformer 2 is connected to the beginning of the primary semi-winding 15 by its end. a primary winding connected the negative terminal 16, a DC source voltage and the emitters of transistors 17 and 18 are inverse circuits eliminate emissions. Diodes 19 and 20 are connected to the beginning and to the end of the primary winding 14, 15 of transformer 2, respectively. The positive terminal 21 is connected to the emitter of transistors 3 and 4. The windings 22 and 23, respectively, of the transformer 9 are included in the basic circuits of transistors 17 and 18. The shaper of alternating pulses works as follows. If a positive half-wave input voltage is applied to the terminal 24 of the alternating voltage source, then under the action of current in the winding 8, the transistor 3 opens, and a constant voltage is applied to the primary half-winding 14 of the transformer 2. The voltage across the base winding 6 keeps the transistor 3 in the open state. A positive impulse is transformed to the output of the former. After a certain time interval, transformer 2 begins to saturate, causing the regenerative process. The current in the winding 6 increases dramatically to the value determined by the base current of the transistor 3, as a result of which a regenerative process of locking the transistor develops 3. The voltage on winding 6 drops. As a result, the transistor 3 is locked, breaking the DC voltage circuit. The transistor 4 in this half cycle of the input AC voltage remains locked. The driver's power consumption from the alternating voltage source at this moment is very insignificant, since only the basic circuits of transistors 17 and 18 are fed from it. When the polarity of the input alternating voltage is changed, the circuit works similarly, with the difference that the transistor 4 opens, a negative polarity pulse is transformed to the output. The falling edge of the pulse is formed by fast regenerative switching processes of the transistors and therefore has a short duration. During the formation of the back front at the output of the former, the ejection of the inverse to the impulse of the sign of the self-induced EMF formed in the primary winding of the transformer is transformed. The EMF of the self-induction of the semi-winding 14 is shunted by the diode 19 and the open transistor 17. The diode 10 prevents bypassing until the transformer 2 is saturated. performed by a chain containing a diode 20 and a transistor 18. In the proposed pulse shaper, the operation stability is improved without degrading the characteristics of the output pulses, since in the power circuit, including a collector junction of transistors, voltage distortions do not occur, and the DC circuit is more stable. In addition, there is no response from the input alternating voltage source to the shaper operation, power consumption from it is reduced, because only low-power basic transistor control circuits are powered from it, which is especially important for multichannel pulse-width regulators and a number of other devices. Claim Invention A shaper of alternating pulses containing a current limiter.