How to Design

I want to design circuits metrix 8x8 infrared emitter and phototransistor detector
That must be designed in any form ?

What is your question?
That schematic shows opto isolators or perhaps an opto slot, which are they?
That design will only cope with one receiver being active at one time.

What is the application or is it an assignment?

PC817A is just an optocoupler.

Tom..... :slight_smile: