You are looking to build you own EMF circuit board. You don’t want to take apart an EMF detector and repurpose the innards, that’s a waste of money. An EMF circuit board would consist of:
3. Light emitting diodes
5. Op Amp
6. Perf Board
8. Soldering Iron with solder
You could purchase all these items and search the web for a bullet proof wiring diagram or schematic and still end up with something you don’t like.
The alternative is you could just purchase the EMF Circuit Board Module from Ghost Gear. They have done the hard work and tested the circuit. It works. You can get it for $35 on their website.
The EMF circuit board module comes completely built with:
1. Adjustable sensitivity
2. Digital output
3. Analog output
5. LED lights
6. Selectable digital output
It takes an input voltage of 6v – 9v to operate.