Drive circuit for weak current control signals

Abstract

The invention relates to a signal drive circuit, in particular to a drive circuit for weak current control signals. The drive circuit solves the problems that the measuring process of an existing drive circuit affects the size of a current signal to be measured, and the drive process affects the linearity of the measurement value. The drive circuit comprises a first operational amplifier OP1, a second operational amplifier OP2, a third operational amplifier OP3, two first resistors R1, two first resistors R2, two third resistors R3, two fourth resistors R4 and a load resistor RL. The same-phase input end of the first operational amplifier OP1 is connected with the same-phase input end of the operational amplifier OP2, and the antiphase input end of the first operational amplifier OP1 is connected with the antiphase input end of the second operational amplifier OP2. A current source formed by the weak current control signals is connected to a connection wire between the same-phase input end of the first operational amplifier OP1 and the same-phase input end of the second operational amplifier OP2 in series. The current across the load resistor RL serves as the output of the drive circuit. By means of the drive circuit for the weak current control signals, the weak current control signals can be accurately measured and driven, and defects of interference with and nonlinear measurement of the weak current signals to be measured are overcome.

Description

technical field [0001] The invention relates to a signal drive circuit, in particular to a drive circuit for weak current control signals. Background technique [0002] The weak current control signal is generally generated inside the sensor, the instrument output and the industrial field environment. Usually, the magnitudes of these currents are relatively weak, and they need to be driven and amplified for subsequent control. The circuit model for this current can be represented as a current source. In order to reflect the characteristics of the actual current signal in the model, the model of the current source is limited as follows: the value is small and variable. The current signal must be generated in a closed loop, and if its magnitude is to be measured, the current must be closed into the measurement circuit. This will cause a problem: the measurement circuit usually has a certain input impedance, and this impedance is introduced into the loop of the circuit signa...

AI Technical Summary

Problems solved by technology

[0003] The invention solves the problem that the measurement process of the existing drive circuit for weak current control signals affects the size of the current signal to be measured, and the drive process affects the linearity of the measured value, and provides a drive circuit for weak current control signals

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