LOW OHM meter equivalent- even lower cost - minus the Multi meter

Measuring low Ohms without a meter - well an extremely inexpensive volt meter as a replacement for a Multi meter. Thanks to t1d100 for the inspiration. Please subscribe, like and comment as your feelings dictate

[@ivolol]

I don't get why either circuit is using a split rail... Since you only want to measure voltages in one direction, using split rail is effectively halving resolution you have for no reason. Since the 602 can sense ground, you should start its sensing from there. In a non-inverting configuration you can also have it showing positive polarity voltages straight away with one opamp.

[@Joftec]

As I said in the video, the circuit is derived from a circuit supplied from a viewer. I did try it without the “ split rail “ and the results were in consistent. Adding the “ split rail “ provided much better stability of measurements , that is why it is there on my version of the circuit. As far as I am aware the gain of a non inverting op amp will wither be unity or 1+ (RF/Rin) , therefore to not have the additional 1 + .The inverting amp sets the required gain , 10 for example and not 11 , and the fact that the 602 is a dual device, why not use it fully and invert with unity gain. Seems the most sensible to me.