How to Spec Solid State Relay

Thread Starter


Joined May 3, 2019
I have another thread where some forum members have helped me formulate my thinking on a project, and as we've made our way through the "big picture" questions I've come to realize that I might be better served by asking some of the smaller questions in their own threads, so I'm creating a few. For reference, here is the "root" thread:

Groundwork: I need to pass 12v power to a component in response to another 12v component being turned on. The fact that the rest of this circuit hasn't been designed yet notwithstanding, I'm wondering if I can start talking about hardware for the solid state relays that will control this auxiliary circuit.

  • What are the factors one must weigh when sourcing solid state relays?
  • How can I go about using these factors to identify a particular part on, say, Mouser?


Joined Jul 18, 2013
1/ The input operating voltage range, typically 5v to 35vdc
2/ The nature of the output/load, AC, DC, Current, etc.
Anything out of range of off the shelf component would require custom built.