SU544075A1 - Device to control the power transistor switch - Google Patents

Description

one

The invention relates to the conversion, regulation, and stabilization of voltage and current, and can be used in pulsed stabilizers, converters, and voltage and current regulators with a pulse-width control method.

A number of devices are known for controlling power transistor switches plj. These control devices for power transistor switches contain one several control transformers, power amplifiers and a number of auxiliary elements of diodes and resistors.

Such devices are characterized by the need to use magnetic amplifiers that reduce the limiting switching frequency of power transistors, the complexity of the devices, and the fact that they do not ensure reliable locking of power transistors during a pause in the control voltage.

SRI.

A device for controlling the power transistor switch 2j is also known.

Closest to the proposed device is a device containing Si2

Lovaya and auxiliary transistors with their own base resistors, a control transformer with ayhodn, w w {{for rectifying and separating diodes, a locking capacitor, and a resistor, a shunt junction emitter-base of the power transistor.

The disadvantage of this device is the additional output winding of the control transformer, as well as the absence of voltage locking the power transistor during a pause in the control voltage; which reduces the reliability of the efficiency. transistor key in general.

11.El of the invention - higher reliability and; Efficiency of the power transistor switch control device by ensuring reliable fusing of the power transistor when it is fed to the primary winding of the cipher transformer with a pause at zero while there is no unlocking voltage at the input of the power transistor.

Claims (2)

This is achieved by the fact that the second output of the rectifying diode and the base resistor of the power transistor are connected to the first output of the transformer winding, the second output of the separation diode is connected to the base of the auxiliary transistor and the collector of the last to the second output of its base resistor. The drawing shows a schematic diagram of the proposed device. The secondary winding of the control transformer 1 through the base. {Base transistor 2 is connected to the base of the power transistor 3 and to the emitter of the auxiliary transistor 4 to the collector of which the output of the locking capacitor 5 is connected. Through the separation diode 6 the end of the secondary winding of the transformer 1 is connected to the base of the auxiliary transistor 4 , and through a rectifying diode 7 - to its collector. The transition of the base. Collector of the transistor 4 is bounded by a resistor 8. The device operates as follows When entering from the secondary winding of the transformer 1 through. a locking voltage resistor 2 (the voltage of this voltage is indicated on the drawing in square brackets), the power transistor 3 will be locked and capacitor 5 charged through diode 7 to a voltage almost equal to the voltage on the control winding with the polarity indicated on drawing. When the control switch, after the locking pulse disappears, becomes zero, transistor 4 is opened by the current flowing through the circuit: capacitor 5 (+), winding. Transformer 1, resistor 2, transition emitter-base of transistor 4, resistor 8, capacitor 5 (-), whereby the capacitor 5 is connected to the emitter-base junction of the power transistor and maintains it in the closed state. At this time, the capacitor 5 is partially discharged by the collector current of transistor 4. At the end of a pause, a winding voltage occurs on the winding of transformer 1 (its polarity in the drawing is shown in parentheses), which opens the power transistor with current flowing through resistor 2, falling the voltage on which leads to the locking of the transistor 4 and disconnecting the capacitor 5 from the transition emitter-base of the transistor 3. At this time, the discharge of the capacitor 5 continues through the tak flowing through the winding of the transformer 1, diode 6 and resis or 8. At the end of the trigger pulse, the power transistor 3 is locked in the same way as the previous pause, with the only difference that immediately after the end of the trigger pulse r; re-absorption of excess ar of minority carriers from the az of the transistor 3, which was in a saturated state . Despite the fact that during this pause, the voltage in capacitor 5 is slightly lower than in the previous one, this is not a matter of principle, since the appropriate choice of parameters for resistors 2 and 8 and capacitor 5 makes it possible to easily obtain an impassable blocking voltage. In the future, the entire cycle of operation of the device is repeated. Consequently, in the proposed device, reliable locking of the power transistor during the pauses of the control voltage is ensured, which leads to a decrease in the power dissipated by the power transistor, and hence to an increase in its efficiency and reliability. The invention The device for controlling a power transistor switch, containing a control transformer, the first end of the secondary winding of which is connected to one of the outputs of the isolation diode, and the second end to the emitter of a violet transistor, 1, which has a base resistor, a string, con:: imitating junction emitter-base power a transistor and consisting of an auxiliary transistor with its own base resistor and a snuffing capacitor A capacitor, characterized in that, in order to increase efficiency and reliability, the second output of the rectifying diode and the base resistor of the power transistor are connected to the first terminal of the transformer winding, the second terminal of the separating diode is connected to the base of the auxiliary transistor, and the latter collector is connected to the second the output of its base resistor. Information sources taken into account during the examination: 1. Moin V.S.Lapshev N.I. Stabilized transistor converters. Energy, 1072, fig. 9-21, 9-22, 9-23. 2.B.NWiteia-hi Dudeev otr.d Tlobtfi D.pee1 Higfti t Hide-ncv Modutor Supplies Using S-itclnTip-Reg-ueoitop5 Hex.eeit-Pó1s1 th) Toup-noie, DsceTnbef, 1475., F ".6 . CA (-J-J (-I-) g {-) 5-CZ