Isolated relay board.

[HerpaDerp]

Can anyone recommend a reliable 16 channel (at least) opto isolated relay board for my Pi 3. I bought a XCSOURCE 16 Channel, only had it in operation a couple of weeks, and it's only switching a fairly light load a couple of times a day.
I've now got 2 of the outputs stuck 'on', there's no LED indicating the output is on but the contacts are closed instead of open.

I'm hesitant in getting a replacement since it's a PITA to unwire then everything if they're not a very good board and I'll have the same problem in a few more weeks, so I don't mind scrapping it as they're only about £15.

Thanks

[Gert van Loo]

No, I don't know another board at the moment.
But if you are forced to re-use the same type of board try to add a 'snubbing' circuit (RC)
over the relay contacts. I know it is even more wiring but the relays may live longer.
(Make sure your C is a high voltage type).

As a side note:
I just spend two hours reading up on safety distances and PCB design as I have seen questions about
a relay circuit board like that being used with the Raspberry-Pi for the fifth time in a week.
I have only limited access to data about the board, but what I can see the PCB does NOT comply with the safety required for mains circuits.
There are several texts about PCB creepage for mains voltage on the web, bust most seem to agree on a distance of 2.5 .. 2.6mm.
I have spotted at least one position where the distance is much less**.
What is more: at that point it would have been trivial to lay the track different and thus comply with the 2.6mm.
In general it gives me a very uneasy feeling that a board with mains application has such obvious glaring errors in it.
The designer seem to have paid very little attention to the safety aspect of the PCB design.

relay_Bedit.jpg (40.06 KiB) Viewed 1158 times

Oh by the way: the opto couplers don't offer any safety the way the are placed, they only offer electric isolation for
the connected computer.

**I have compared the layout at that point with the distance between two IC pins which is 0.1inch:2.54mm.

[HerpaDerp]

Thanks for the reply, I did have my doubts about mains voltage with these boards given the fact so much is crammed in to such a small space.

Not sure if there's a practical solution, maybe switching 12v with the onboard relays and using that 12v to trigger other relays mounted off the board, messy and takes a lot of space up though, probably wouldn't fit in the box I'm using

[DougieLawson]

Not sure if there's a practical solution, maybe switching 12v with the onboard relays and using that 12v to trigger other relays mounted off the board, messy and takes a lot of space up though, probably wouldn't fit in the box I'm using

That's what we did for the major project I've built using a Raspberry & a relay board. It also meant we could keep the 230V wiring short and closer to the switched load. Running 12V from the Raspberry to slave relays meant most of our wiring loom was running at safe voltages.