SU1555709A1 - Record amplifier - Google Patents

Abstract

The invention allows for the function of summing the recording currents and biasing the recording amplifier without the use of uterine products. The device contains a two-stage direct-coupled amplifier, the recording head 16 being connected via a capacitor 15 between the collector of transistor 2 and the emitter of transistor 1. At the same time, the collector of transistor 2 is connected through a resistor 4 to a pole of a unipolar power source 5, to which the resistor 3 is also connected The second pin of which is connected to the base of transistor 2 and the collector of transistor 1, to the emitter of which is connected the second pin of head 16 and rheostat 6, connected by another pin to common wire, and resistor 7 is also connected to it associated with the second output of the emitter of the transistor 2 and the resistor 8, the other output of which is connected to the base of the transistor 1 and two circuits consisting of resistors 9, 10 and capacitors 11, 12 connected in series. The other terminals of these circuits are device inputs.

Description

one

(21) 4060050 / 24-10

(22) 04/25/86

(46) 04/07/90. Bul № 13 (72) Yu.A. Bulychev

(53) 681.84 (088.8)

(56) USSR Copyright Certificate No. 525227, cl. H 03 F 1/34, 1974.

USSR Author's Certificate No. 1191939, cl. G 11 B 5/00, 1984.

Japanese Patent No. 60-1689, cl. G 11 In 5/03, published. 1985.

Goroshkov B.I. Radio electronic devices. - M .: Radio and Communications, 1984, p. 124, Fig.4.46.

(54) RECORDER AMPLIFIER

(57) The invention allows for the function of summing recording currents and biasing the recording amplifier without the use of products. The device contains a two-stage amplifier with

directly connected, and the recording head 16 is connected via a capacitor 15 between the collector of transistor 2 and the emitter of transistor 1. At the same time, the collector of transistor 2 is connected via a resistor 4 to a pole of a uni- polar power source 5, to which the resistor 3 is also connected which is connected to the base of the transistor 2 and the collector of the transistor 1, to the emitter of which is connected the second terminal of the head 16 and the resistor 6 connected by another output to the common wire, and the resistor 7 connected to it by the second output is connected to it nzistora 2 and the resistor 8, the other terminal of which is connected to the base of the transistor 1 and the two chains composed of conductive resistors and capacitors 9,10 11,12 connected in series. The other terminals of these circuits are device inputs. 1 il.

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The invention relates to instrumentation engineering, in particular, to devices for amplifying signals with negative "feedback" circuits.

The purpose of the invention is to stabilize the gain when summing two signals.

The drawing shows a circuit diagram of a recording amplifier.

The amplifier contains the first 1 and second 2 transistors, the collectors of which are connected via the first 3 and second 4 resistors to the same terminal of the power source 5, the emitters through the third 6 and fourth 7 resistors to the terminal of the power supply connected to the other terminal of the power source 5. The emitter of the second transistor 2 is connected via the fifth resistor 8 to the base of the transistor transistor 1, which is connected through the sixth 9 and seventh 10 resistors and the second 11 and third 12 capacitors to the input terminals 13 and 14, respectively (for example, recording and biasing signals) . The collector of the second transistor 2 is connected via a first capacitor 15 (e.g., a coupling) and a load 16 (e.g., a magnetic recording head) to the emitter of the first transistor 1. A housing terminal 17 is common to signal and power sources.

The resistor 6 is made variable to set the rated current through the load. On the input side, the amplifier is an inverting adder, i.e. stabilizer then

Editor N. Tupitsa

Compiled by V. Dobrovolsky

Tehred L.OleynikKorrektor N.Revska

Order 556

Circulation 478

VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5

terminals at the input terminals, which is provided by a series negative feedback circuit.

Claims (1)

The Invention A recording amplifier containing two transistors of the same conductivity, the collectors of which are connected via the first and second resistors respectively to one terminal of the power supply, the collector of the first transistor is connected to the base of the second directly, the emitters of the transistors are connected via a third and fourth resistor to the terminal of the transistor. Another terminal of the power supply, the emitter of the second transistor, is connected via a fifth resistor to the base of the first transistor, to which one terminal of the first terminal is connected. A capacitor, a second capacitor connected by one output to a collector of the second transistor, a sixth and seventh resistors, a third capacitor, an input terminal, two load terminals, characterized in that, in order to stabilize the gain when adding two signals, the load terminals are connected between the other output of the second the capacitor and the emitter of the first transistor, the input terminal is connected through the sixth resistor to another output of the second capacitor, the input additional input terminal is connected via the seventh resistor p and third capacitor to the base of the first transistor. Subscription