It covers the IL300's coupling specifications, and circuit topologies for photovoltaic and photoconductive amplifier design. This application note presents isolation amplifier circuit designs useful in industrial test and measurement systems, instrumentation, and communication systems. Specific designs include. Many supply manufacturers have elected to offer power supplies that satisfy all national and international safety insulation criteria by selecting power transformers and feedback devices that meet a 3750 VAC withstand test voltage. Feedback systems that use optocouplers easily comply with this. The LOC product is intended to give the designer an alternative to bulky transformers and “non-linear” optocouplers for many applications. The LOC product is intended to. ment. The feedback photodiode captures a percentage of the LED's flux and generates a control signal (IP1) that can be used to servo the LED drive cu rent.