PC817 OptoCoupler Optoisolator DIP IC

DataSheet:

A Optocoupler also called a photocoupler, optical isolator or opto-isolator is a small chip that transfers signals between two isolated circuits using light. A basic optocoupler uses a led and a phototransistor, the brighter the led the more current is allowed to pass through the phototransistor. For more info on how optocouplers work check out this link ( OPTOCOUPLER )...

In this instructable I will show you how to isolate and control the speed of a 12v PC fan with your ARDUINO board, This circuit could be used to control many things with minor modifications to the circuit.

An optocoupler is analogous to a relay which isolates two circuits magnetically. They differ with relays in the sense that they are smaller in size and allow fast operation. 4N35s are commonly used in interfacing an electronic circuit with the parallel port of a computer.

Pin Diagram:

Pin Description:

Pin No	Function	Name
1	IR diode’s anode	Anode
2	IR diode’s cathode	Cathode
3	Not connected	NC
4	Phototransistor’s emitter	Emitter
5	Phototransistor’s collector	Collector
6	Phototransistor’s base	Base