SU1555812A1 - Amplifier - Google Patents

Abstract

The invention relates to electrical measuring equipment and can be used in measuring converters and information measuring systems. The purpose of the invention is to increase accuracy. The amplifier contains a key 1, a bridge 2 resistances, resistors 3–7, operating terminals 11, 12, switch 14, capacitors 17, 18, voltage regulator 21, r-r 22, transistor 23. Resistors 8 are inserted into the amplifier - 10, repeater 13, switches 15, 16 and two sources 19, 20 bias. At the beginning of the bridge imbalance, the output current of the amplifier is proportional to the voltage on the diagonal of the bridge and does not depend on the bias voltage of the operational amplifier. 1 il.

Description

- E

CM 1

0 + K (GTG + G +

Ki keihm rf

where is R; - resistance of the 1st resistor

ra;

I is the current through the fifth resistor; ROI ,. / output impedance myDI M

ta; EJ, E - first 19 voltages and

second 20 sources; Eg., - emf offset of the first op-amp 11;

CM1

45

ensuring the operability of the first AND and second 12 OU, in the absence of the first source (19, the output voltage of these amplifiers should be 50 below the supply voltage). The output current of the entire amplifier is

9YAh

W1

E1R5D .R,

 .X

55

R, “R

Rforj

It can be seen from the above expression that when the condition is satisfied, the R 9 RT output current of the circuit does not depend on the current consumed by the element

9YAh

W1

E1R5D .R,

 .X

five

R, “R

Rforj

It can be seen from the above expression that when the condition is satisfied, the R 9 RT output current of the circuit does not depend on the current consumed by the element

amplifier (I), and is equal to

Eh

R,

If the bridge is unbalanced, the output current of the amplifier is proportional to the voltage on the diagonal of the bridge and, as can be seen from the above formulas, does not depend on the bias voltage of the operational amplifier.

The first 19 and second 20 sources can be implemented on both zener diodes and diode circuits. The stabilizer 21 can be performed according to a standard scheme.

Claims (1)

Invention Formula An amplifier containing a voltage stabilizer, between the output and the common bus of which are connected in series the key and the resistance bridge, the first operational amplifier, the inverting and non-inverting inputs of which through the first and second resistors are respectively connected to the diagonal of the resistance bridge, the second operational amplifier, transistor, the base, the emitter and collector of which are connected to the output and the inverting input of the second operational amplifier and the input of the voltage regulator, respectively, the first ne eklyuchatel, input and a first output of which is connected to the output of the first and the non-inverting input of the second operational amplifier respectively, the first and second capacitors connected between the first 55812 6 and the second outputs of the first switch and the common bus voltage regulator, respectively, the generator, the output of which is connected to the control inputs of the switch and the first switch, the third and fourth resistors, the first terminals of which are connected to the inverting and non-inverting inputs of the first operational amplifier, respectively, and A fifth resistor connected between common voltage regulator and amplifier buses, characterized in that that, in order to increase accuracy, between the second output of the second switch and the inverting input of the first operational amplifier, serially connected repeaters are introduced A sixth resistor is connected between the emitter of the transistor and the second output of the fourth resistor and the sixth resistor is connected in parallel; the outputs of the inserted second switch are connected to the second output of the third resistor; the third switch is connected to the inverter through the eighth resistor. the input of the first operational amplifier, and the first output - with a common bus voltage regulator, between the second output of the fourth resistor and the common bus two-wire amplifier the first bias source is introduced, between the second output of the third switch and the common bus of the two-wire amplifier, the second bias source is introduced, and the control inputs of the second and The third switch is connected to the output of the generator. Editor I.Shmakova Compiled by Y. Rogatkin Tehred M.Morgental Proofreader M.Kucher va Order 1860 Circulation 660 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 Subscription