I recently made a post about measuring positive and negative voltage from a coil in a changing magnetic field. I got some good suggestions but after trying a few out i realised that the coil itself cant be exposed to the arduino's 5v. The coil wont produce any voltage when exposed to a constant current. This made me start experimenting with some diodes but i cant seem to get any results. I have tried 2 different schematics as seen in the picture, can anyone see what im doing wrong? The ac source represents my coil. For more info about the project here is the original post: Measuring negative voltage given by a coil using Electromagnetic induction - General Electronics - Arduino Forum
This loses the context from the original post. I suggest asking a moderator to combine the threads, and don't do it again. At the very least, you should edit the link to the previous thread and make it clickable...
I got some good suggestions but after trying a few out i realised that the coil itself cant be exposed to the arduino's 5v.
I really don't think anyone suggested "exposing the coil to 5V" over there. It's more likely you just got lost somewhere in the implementation. Your diode circuits look pretty random, I don't see what you're trying to do there... the diodes will just create all kinds of problems for you. Forget about them.
I had to go back to your previous post, its NOT a good idea to split them its a PAIN.
Reply #9 gives a 2.5v offset to allow your AC to be measured without going below zero.
Realistically you would be better using an op amp to condition your signal - depending on what you are trying to do.