Opto Triac circuit versus SSR

[hobbyelectronics]

Hi,

I am looking at using a TRIAC circuit to drive a 230 VAC load. I understand how to drive a TRIAC using an opto-coupler.
I have the need to drive the load using phase control or possibly some sort of burst control to allow the power to the load to be varied. This will be based around a small ARM M0+ micro, with zero crossing detection so I can fire the TRIAC or turn on the SSR at the right time.

The only question I have, is apart from cost why would I use discrete components for this instead of just using a SSR (Non ZCD)?
Many SSRs are basically a TRIAC based circuit with opto-coupling, filtering and snubber etc built into one unit.
Looking at switching speeds etc and other specs, it would seem many SSR's would be perfect for this.

Is this just down to cost, or perhaps their are other reasons why or why not to use an SSR. Or have I got this totally wrong and missing something here.
Some small SSR's for a relatively low power AC load seem fairly low cost.

Thanks
Paul

[moffy]

The advantage of the SSR is that it is a black box with a specification that all you need to use is abide by the spec and provide a suitable input. You don't need to know about triacs or mosfets or heatsinks etc., but you pay for the privilege, and if you need something non standard then you are stuck. Knowing about triacs you are free to roll your own or not.

[hobbyelectronics]

Yes, that's how I understand it.
Seems that for my case using a small SSR would be ideal.
Saves some PCB space as well and assembly time / cost instead of discrete components.
Thanks