Maker Pro
Maker Pro

Opto-isolator

Harald Kapp

Moderator
Moderator
Some are, some not.

An optoisolator is a transistor (typically NPN) whose base current is controlled by the light output of an LED. More light -> more base current.

Google it. First hit (Wikipedia)
 
Like Harald Kapp and Jotto said.
It's primarily to isolate a higher voltage circuit, from a lower voltage circuit.
 
Top