Three Phase Power Transformer Current Monitor

This circuit can be used to monitor the current value of any phase of a three-phase power transformer
during operation to detect whether the transformer is operating normally.
    The ruler is a current sampling resistor in series with the phase line, and the INA110 is a fast-establishing, gain-settable instrument amplifier
whose parameters are relatively close to those of the AD524. The basic parameters are: low bias input current 50pA (maximum), fast settling time
4°C, high CMRR (common mode rejection) of minimum 106dB, 90dB (10kHz), low temperature drift (lo~50) ×
10 -6/℃, Low input drift 2 VV gate C, gain can be set to l, 10, 100, 200, 500. Even if the voltage generated by the current passing
    through R is very weak, a very small voltage will appear at the differential input end of INAI10. However, due to the high sensitivity of INA110, the signal will still be amplified, and the amplified signal will be isolated and amplified by IS0102. , output isolation voltage vo.