SU1224966A1 - Two-step amplifier - Google Patents

Abstract

The invention can be used in high-power, high-quality amplifiers of 3 production plants. The device contains two input transistors (T) 1,2, two output T 3,4, four additional T 5,6,7,8, a current stabilizer 9 and a resistor 10. As a result of combining the emitters of additional T 5 and 6, their transitions are base the emitter is connected in parallel and at any value of the input voltage, the voltage at the transitions of additional T 5.6 will not exceed Ug.g (1B). Such a circuit solution ensures reliable mutual protection of base-emitter transitions of an additional T 5.6 at an input voltage amplitude up to the supply voltage. 1 il. fff SL ffx. O- G 1 LO. l ISO 4 (; about Oi O5

Description

f 1

The invention relates to radio engineering and can be used in electrical and sound reproduction equipment, in particular, in high-power, high-quality amplifiers of sound reproducing installations.

The purpose of the invention is to expand the dynamic range.

The drawing shows a circuit diagram of a push-pull amplifier,

The two-cycle amplifier contains the first and second input transistors 1 and 2, the first and second output transistors 3 and 4, the first, second, third, quarter additional transistors 5-8, respectively, current regulator 9, resistor 10,

Push-pull amplifier works as follows.

At zero voltage, the first and second additional transistors 5 and 6 are closed. The collector currents of the first and second input transistors 1 and 2 are approximately equal to the collector currents of the third and fourth additional transistors 7 and 8 and are set by the current regulator 9. By the voltage drop at the base-emitter junction of the first and second input transistors 1 and 2, the first and second output transistors 3 and 4 open, their collector currents are set proportionally to the collector currents of the first and second input transistors 1 and 2,

The output of the push-pull amplifier is set to a voltage close to zero,

As the input voltage increases (decreases), the voltage at the output of the push-pull amplifier increases (decreases). At the same time, the collector current of the first (second) additional transistor 5 (6) increases. This current, amplified by the third (fourth) additional transistor 7 (8), enters the base of the first (second) output transistor 3 (4), providing the necessary load current, Maximum the value of the load current is set by the resistance of the resistor 10 "

With a positive (negative) polarity of the input voltage, the first (second) additional transistor 5 (6) opens, and the second (first) additional transistor 6 (5) terminates. Base emitter transitions

2249662

The first and second additional transistors 5 and 6 are connected in parallel to each other, therefore, for any value of the input voltage, the reverse voltage across the base-emitter junction of the closed second (first) additional transistor 6 (5) does not exceed the maximum voltage U. on the transition base-emitter open

to the first (second) additional transistor 5 (6), i.e., several times less than the maximum allowable reverse voltage of the base-emitter. Maximum input amplitude

15, the voltage can approach the supply voltage, while the transition, the base-emitter of the first (second) additional transistor 5 (6) is reliably protected from reverse breakdown

20 by means of a direct shifted base-emitter junction of the second (first) additional transistor 6 (5),

Thus, as a result of the connection of the emitters of the first and second additional transistors 5 and 6, the base-emitter transitions of the first and second additional transistors 5 and 6 are connected in parallel and for any value of the input voltage at the transitions of the first and second additional transistors 5 and 6 does not exceed

iJB,) 35 Such a circuit solution provides €: t reliable mutual protection of the base-emitter junctions of the first and second additional transistors 5 and 6 with the input voltage amplitude up to

40

45

50

before the supply voltage.

Claims (1)

Invention Formula Two-cycle amplifier containing the first and second input transistors, the bases of which are combined, the collectors are combined and connected to the load and to the combined emitters of the first and second output transistors connected according to a common collector circuit, the bases of which are connected to the emitters of the first and second input transistors - 55 second and second additional transistors, the bases of which are combined and connected to the bases of the first and second input transistors, collectors - Such a circuit solution €: t reliable mutual protection base-emitter of the first and complementary transistor amplitude of the input voltage before the supply voltage. Invention Formula Two-cycle amplifier containing the first and second input transistors, the bases of which are combined, the collectors are combined and connected to the load and to the combined emitters of the first and second output transistors connected according to a common collector circuit, the bases of which are connected to the emitters of the first and second input transistors - second and second additional transistors, the bases of which are combined and connected to the bases of the first and second input transistors, collectors - 3 1224966 to the combined through stabilizing and second additional the current to the bases of the third and the output transistors of the counter of the fourth additional transient-positive structure of the second input, Stores included according to the scheme with the fourth additional and first the emitter, the collectors of which are sub-5 additional and output switches to the emitters of the respective, differing the first and second transistor inputs so that, in order to expand dirov, and the emitter of the first polar-band, emitters The main transistor is connected via the first and second resistors to the secondary bus connected to the common bus, the structure of the 10 transistors of the first input combiner, the third complement.