Quote Originally Posted by dkulp View Post
Probably a smaller form factor and hopefully cheaper DC SSR. My "hack" to the dirk cheaps uses a transistor, but that requires customer firmwares on the controllers and also doesn't provide any isolation. I was thinking of trying to experiment with sticking an opto-fet or opto-transitor. Either option would use roughly the same form factor of the DiskCheap. Obviously a much lower current that the full DC SSR (likely around .4A per channel looking at some of the specs), but for a lot of applications, that's probably enough.
I haven't seen where isolation has been that important for DC controllers - - there are 300+ Ren48LSD's out there representing over 14,000 channels and have never seen a case where the high load power somehow got back through the PIC, back through the RS485 chips and back to the PC - ever. It would be easy to just recreate the output portion of the Ren48LSD - it would still require the flipped outputs, etc as you do today if using a Renard non-SSR controller or even with an Arduino type output. Breadboard out with some cheap transistors and 470 ohm resistors - done...