Remote Control 4 Channel

[jra]

Pretty much all of the relay boards you find online have opto-isolators because they are all clones of the same design.

[kobuki]

Pretty much all of the relay boards you find online have opto-isolators because they are all clones of the same design.

It's contrary to what I've seen but indifferent anyway. OP will probably choose the solution best suited for him.

[jra]

Maybe we're talking apples and oranges.  The board OP was referring to is a clone of the Sainsmart 4-channel relay and the inputs are optoisolated, see schematic in http://www.selloutsoon.com/albums/documents/20-018-101/4%20Relay%20Module.rar

[kobuki]

Maybe we're talking apples and oranges.

Your original note:

Pretty much all of the relay boards you find online have opto-isolators because they are all clones of the same design.

So we were talking generally until your latest post. What OP posted is an RC board, and I see no o.i. on it, though I didn't see its schematics. I'd recommend one in any case.

EDIT: re-edited whole post to reflect on what was being answered to me. Sorry for bringing this a little off-topic.

[2cvman]

May be a better option for AC loads is an SSR

http://www.ebay.co.uk/itm/5V-2-Channel-Solid-State-Relay-SSR-Module-Board-for-Arduino-W-Resistive-Fuse-UK-/151719004558?hash=item235328498e:g:PvQAAOSwT6pVg7yY