Author Topic: Help identifying what opto isolator is being used in the schematic  (Read 874 times)

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Offline NoSkillzTopic starter

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Hello and thank for taking the time to read this. I started building this open source cm3 module handheld. I ordered the boards and all the ics and passives and didn’t notice that the opto isolator was not labeled. I’m very new to electronics. But i have searched and read a lot on the subject and i think that a pc814 might work. But I wanted to see if any of you guy might no a better one to use? and the pictures that are posted up of the device are super blurry so i can’t make out the numbers on the chip and again thanks for your time .
 

Online ledtester

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Re: Help identifying what opto isolator is being used in the schematic
« Reply #1 on: September 11, 2019, 04:12:50 am »
In my _expert_ opinion I don't think the choice of optocoupler matters much here - I think pretty much any device with a compatible footprint will work.

Here's the internal schematic of the PC814:

831951-0

The back-to-back diodes on the input means it is designed for AC signals - not for a DC control signal that your schematic shows. That said, I would hazard to guess that the PC814 in all likelihood will work fine in this circuit.

I would try any one of the 4-pin optocouplers on this page specified for DC input:

https://www.jameco.com/shop/keyword=Optocoupler-4-Pin

Since you already have a pcb, just make sure the pinout and footprint match.

The hackaday.io project seems to be here:

https://hackaday.io/project/94791-retro-cm3-a-powerful-retropie-handled-game-consol

If anyone has Altium there is a PCBDOC file available there. Perhaps it has a BOM?

Update: Just noticed from the photos that the board uses SMD components. So it would be a good idea to get the footprint and pin assignments from the PCBDOC file.

« Last Edit: September 11, 2019, 04:21:41 am by ledtester »
 

Online ledtester

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Re: Help identifying what opto isolator is being used in the schematic
« Reply #2 on: September 11, 2019, 04:31:42 am »
Well, I did find a BOM in this repo:

https://github.com/Dean-Chu/Retro-CM3

It's an Excel file:

https://github.com/Dean-Chu/Retro-CM3/blob/master/Retro-CM3_HW/Retropie-BOM.xlsx

However, it doesn't seem to include any opto-couplers.
 

Offline NoSkillzTopic starter

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Re: Help identifying what opto isolator is being used in the schematic
« Reply #3 on: September 11, 2019, 04:41:31 am »
yes the repo is a updated version i already had all the part for the first version thanks for looking tho
 


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