What is Opto-coupler?

 

Ø  Opto-coupler is an electronic component that transfers electrical signals from one circuit to another circuit with isolation

Ø  These are also known as Opto-isolator, photo coupler, and optical isolator

 

 

Uses

Ø  Isolation between circuits

Ø  It prevents damage in one circuit due to damage in another circuit

Ø  Prevention of unwanted noise

Ø  Both circuits can work on different voltage levels

 

Opto-coupler: PC 817



Ø  It has four pins

Ø  Pin-1 is Anode & 2 is Cathode of the LED



Ø  Pin-3 is Emitter & 4 is Collector of the Photo Transistor

Ø  When light of LED falls on the Phototransistor base it conducts

Ø  If there is fault in either circuit, another circuit will remain safe

Ø  This is 4 pins opto-coupler component

Ø  Pin-1 is Anode & 2 is Cathode of the LED

Ø  Pin-3 is Emitter & 4 is Collector of the Photo Transistor

Ø  Mark on top-left, shows that pin counting starts from here

Ø  SMD version is also available in markets

 

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