“This article explains to connect an Optocoupler System.
This system is used to isolate the two power sources. Typical applications include medical where the patient needs to be isolated from possible power supply faults and surges to avoid electric shocks. Those systems are used in EEG an ECG machines.
The amplifier is usually powered by rechargeable batteries.
The circuit can work with just one 1.5 V power supply.
Supplies:Parts: optocoupler, 8 pin wire wrap socket, 1 kohm resistor - 5, 10 kohm - 1, 1 Megohm potentiometer - 2 (second potentiometer could be just a variable resistor to save money), wire wrap wire, insulated wire, power supply (3 V or 1.5 V can be implemented with AA/AAA/C/D batteries), matrix board, battery harness.
Tools: USB Oscilloscope, wire stripper, pliers, wire wrap tool.
Optional parts: Solder.
Optional tools: Soldering iron, multi-meter.”