Posted by dapj20 on Jun 17, 2021 in Analog-Mux, Multimeter-DMM, Test-Instruments
U3 LF 356 is used as a constant current source (sink as the current is negative). R4, R5, R7 and R9 set the four resistance ranges by changing the constant current in decade steps. R2 is for calibration of resistance range. The A-B digital control of… more »