SU1418763A1 - Scale amplifier with variable transfer coefficient - Google Patents

Abstract

The invention relates to amplifier technology and can be used in analog computers. The aim of the invention is to increase the accuracy that is achieved by expanding the dynamic range of the input voltage and increasing the input resistance. The scale amplifier with a controlled gain includes an operational amplifier 1, a scale resistor 2, the first 3 and second 4 amplifying transistors, a current-generating resistor 5, a phase inverting unit 6, a signal input 7, an output 8, a control input 9, a source 10 of the reference voltage wives The phase inverting unit 6 comprises the first 12, the second 13, and the third 14 large-scale resistors, a compensating diode 15, an operational amplifier 16, and a source 17 of the mixing voltage. The operation of the device is based on adjusting the gain by a signal from control input 9. 1 sludge. F (L

Description

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The invention relates to amplifier technology and can be used in analog computing circuits.

The aim of the invention is to improve the accuracy.

The drawing shows a functional diagram of a large-scale amplifier with a controlled transmission coefficient. - The amplifier contains an operational amplifier 1, a large-scale resistor 2, the first 3 and second 4 amplifying transistors, a current-setting resistor 5, a phase inverting unit 6, a signal input 7, an output 8, a control input 9, a source 10 of the reference voltage, a bus 11 zero potential, first 12, second 13 and third 14 large-scale resistors, compensating diode 15, operational amplifier 16 and bias voltage source 17.

reference voltage source 10;

m is the temperature potential. Given that voltage is on. the compensating diode 15 is equal to the base-emitter voltage of the first amplifying transistor 3 and the resistance of the second 13 and third 14 scale resistors are equal to each other, the amount of current through the current supply resistor 5 is equal to

tr ru

R5 J YOU ARE .D R ji-K.y

(3)

where is the resistance of the first May of the staff phase-inverting block 6; 20 current supply resistance

resistor 5.

Substituting (.3) into (2) and then into (1), we get

Scale amplifier with control - 25 transmission coefficient works as follows.

If we neglect the input currents of the operational amplifier 1 and assume that its gain factor is infinitely large, the voltage at its output is

and

ex

+ Ik.Rj.

(one)

where Ugy is the input voltage of op amp 1; 1ts2 - current collector first

amplifier transistor 3; R2 is scale Q resistance

resistor 2,

The collector current of the first amplifying transistor 3 is determined both by the current through the current setting resistor 5 and by the voltage from the control input 9. The current through the current setting resistor 5 is determined by the output voltage of the phase inverting unit 6,

The collector current of the first amplifying transistor 3

(-iU ,, + lJ; (2)

35

45

Ig5

di

current through the current-setting resistor 5;

control voltage equal to the voltage difference from control input 9 and

V,

 K (4UJ-U,

(four)

Q

five

0

five

five

55

where KSLI,) is the transfer coefficient as a function of the magnitude of the healing voltage.

The scale amplifier with a controlled gain is characterized by higher operating accuracy due to the effects of expanding the dynamic range of the input voltage and increasing the input resistance.

Claims (1)

Invention Formula A scaled gain amplifier containing an operational amplifier, between the inverting input and the output of which the scale resistor is connected, the output of the operational amplifier is the output of the scale amplifier, the first and second amplifying transistors whose emitters are connected to the first output of the current resistor, to the inverting input operational amplifier connected to the collector of the first amplifying transistor, the base of which is the control input of a large-scale amplifier, characterized by By the fact that, in order to increase accuracy, a phase inverting unit and a source of reference voltage are introduced into it. 31418763 moreover, the output of the source of the reference block, the output of which the connection is connected to the base of the second force with the second output of the current-conducting transistor, collector resistor, non-inverting which is connected to the bus, the zero input of the operational amplifier is potential, output operational signaling input of scale the amplifier is connected to the input of the phase inverter amplifier.