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I have a Geeetech Prusa i3 x and was wondering if and how anyone else has ran their heatbed off of an external 12 or 24v power supply. From what I been reading, I think whatever you use you have to use a diode for backfeed but I was wondering which one would be more reliable and work the best. Thanks guys
I have a SSR for my heatbed. It has worked flawlessly for a few months now. It is connected through my Rumba board and shares the power supply with everything else.Quote:
Originally Posted by nitrografix
Typically, the mechanical relays with an electromagnet need a reverse biased diode across the relays coil. That is because when the current is switched off to the relay's coil, you get a big inductive kick that can fry the circuitry driving the coil. That is the only time a diode is required as far as I know. And a you wouldn't need that with a solid state relay because there is no coil. Maybe the Solid State Relays need a diode for another reason?Quote:
Originally Posted by nitrografix
Probably true that you do not need a protection diode but just stick them in anyway. They do no harm and cost pennies so if you don't know if it needs a protection diode or not it makes sense to just use one.Quote:
Originally Posted by Roxy
Transistors often have them built in anyway.