dkilshaw

sorry to be thick but cant see how to make a current source Ive thought about this a bit longer and assume the following Remove all points of P1 then put a current source into R8 referenced to ground so put current source accross pin 12 & 10 And in ref to current source I assume the PNP is on the output of the opamp and the load in the collector leg of the line and the emmiter is fed back to the neg input of the op amp, potential divider on the positive input to the op amp If this is the case can do i need to use a split rail supply to the op amp ? I would prefer not as this standard PSU circuit negates the need for one

Can this circuit be modified to allow for a decade box to drive the voltage. I.e. 1000 ohms = 1 volt , 2000 ohms = 2 volts. Ive tried putting a decade box but am seeing a non linear effect on the output voltage. I assume this is due to the gain on U2. Any ideas

An suggestions on good points The neg rail i assume removing the link from point 4 (neg O/P) to c5 r10 node positive sense have you any ideas

short the following groups 1,2 3,4,5 6,7,8 9,10,11 13,14

Has anybody tried to modify this circuit to allow remote sensing of the outputs over long leads ?