I'm attempting to adapt a project with the wiring diagram shown here: http://www.glacialwanderer.com/hobbyrobotics/?p=9

But instead of the electromechanical relay used in the above link, I'm using an SSR with a 25-amp load current capacity (this one: http://www.fotek.com.hk/solid/SSR-1.htm)

My question is, should I still include the diode and transistor as shown in the first link's wiring diagram? Would that be redundant/unnecessary when using an SSR as compared to an EMR? Just wiring up the Arduino pin to the SSR seemed to successfully be able to toggle the SSR's load circuit (with the AC disconnected of course) but I think I should be concerned about adequate safety, reliability etc...