OPTOCOUPLER CIRCUIT diagram!

[ali ghafoor]

i need the simplest U-shaped optocoupler circuit diagram...i am to meaasure the speed(RPM) of a dc-fan controlled by a miocrocontroller....plz help me out!!

 

[KJ6EAD]

Is this what you need? Learning to Use an Optocoupler or Optoisolator.

Or did you mean something like this: Optocoupler with slot for light block, shown with mechanical block (light barrier) 05-06-09 - Semiconductors and electron tubes - Electrical engineering (DIN EN 60617) - Symbols - Services - Festo Didactic or this: **broken link removed**?

It sounds like you need an incremental optical encoder. This is a search term hint.

 

[ark5230]

It looks you need a light beam source and a light detector with response time consistent with your speed measuring arrangements. Perhaps a microcontroller based system should serve the purpose.

 

[zuisti]

Do you want only to measure the speed or also to control it?