Solid State Relays (SSR) and thier use

[navymustang]

I have recently purchased an 8-channel SSR to be controlled via an Arduino Mega 2560. I use mechanical relays all the time. I'm new to SSRs, so can someone tell me why you are only supposed to control A/C loads and not D/C loads with them?
Thanks

[mickc]

You can control DC loads with them, if they are DC SSRs.

This explains it pretty well:
https://www.phidgets.com/docs/Solid_State_Relay_Primer#How_SSRs_Work

[ame]

Indeed. There are two types of SSR. The ones you have, and the ones you need. 

[navymustang]

MIc, thanks - great article.

And indeed, I have bought something I should not have. But being a good builder, I will find a use for it in the future.