SU251665A1 - DEVICE FOR WIDE-PULSE CONTROL OF TRANSISTOR - Google Patents

Description

The devices for pulse-width control of a transistor are known, which comprise an alternating rectangular voltage generator and an input transformer, the secondary windings of which. The corresponding blocks for forming the unlocking and locking signals are connected to the input transCTCTa.

The described device differs from the known ones in that the unlocking signal shaping unit is equipped with an additional transformer, the primary winding of which is connected to the collector of the specified transistor and ends with a midpoint and iK corresponding to the input transformer winding, and the secondary winding through a rectifier and resistor to the control transition of this transistor.

This increases the efficiency. and protects against overloads.

The drawing shows a diagram of the device.

In the steady state, variable rectangular voltages are applied to the windings of the input transformer 1.

He suggested that at some moment in time there is a change in the polarity of these orientations. At the same time, through the magnetic amplifier 2, which is included in the blocking signal forming unit, only a small amount of no-load current flows through it.

an amplifier that does not have a noticeable effect on the state of the transistor 3. A difference between the voltage on the corresponding half-winding of the input transformer is applied through dividing diodes 5 or 6 to one of the polo.vins of the primary winding of the additional transformer 4, which is connected to the block forming the unlocking signal and by direction on the previously closed Trasztor 3. If the sign of the indicated difference corresponds to the conductive state of the isolation diode (5 or 6), then to the secondary circuit of the transformer 4 through the diodes 7 or 8 rectifiers And the resistor 9 receives a signal providing the base current through the control junction of the transistor 3. In this case, the voltage across the transistor decreases, which leads to an additional increase in the base current. Avalanche occurs; Knowing the process of switching on the transistor 3, at the end of which the latter goes into the region of saturation, and the load 10 sets the voltage and the power supply source.

In this state, the transistor 3 is located until the core of the magnetic amplifier 2 is saturated, when the base current decreases so much that the transistor 3 goes into a linear region, and the voltage across it (starting with a reverse

5 1s a different switching process of the transistor for the last of which goes to the cutoff region, and the voltage on the secondary windings of the transformer 4 becomes close to zero. When changing the polarity of the voltages on the windings of the input circuit 1p; the format of the process: sy; in the scheme, the similarities are discussed similarly above.

Since the switching on and off of the trawl torus occurs regeneratively, the quality of the magnets of magnetic amplifiers practically does not affect the switching dynamics of the transistor.

In case of overload or short circuits in the load circuit, the transistor 3 practically closes, since no current flows through its base.

For the forced connection of the transistor 3 in the presence of a reverse diode, shuitiruyuschego load 10, the circuit uses. A capacitor 11, switched on; a follower) about -with additional windings of both transformers.

The described device can be used in various pulse circuits, for example, stabilizers, controllers, etc.

PRIORITY 3 ABOUT AND

A device for pulse-width control of a transistor, comprising a generator of an alternating ir carbon voltage and

an input transformer, the secondary windings of which are connected to the input of the transistor through the appropriate blocks for the formation of the negative and blocking signals, characterized in that, for the purpose,

k.d.d. and overload protection, the unlocking signal shaping unit is equipped with an additional transformer, the primary winding of which is the middle point of the connection to the collector of the specified transistor n, the ends through the isolating diodes to the corresponding winding of the input transformer, and the secondary winding through the rectifier and resistor -. control circuit of this transistor.