For the 2nd time, I already ordered a relay module w/o first reading and UNDERSTANDING the datasheet, so now I am tasked to ensure that when my 8 channel relay module arrives, I will be able to safely connect it to my Mega (+ 3 shields) w/o fearing that I will fry my boards.
HERE is the link to the datasheet of the relays used. Also to note, I know absolutely nothing about Arduino and electronics save for what I was able to learn on the web for free, so my knowledge is a constant (free) work in progress. With that said, I know there are mathematical ways of determining ratings based on other numbers given, but I don’t know any of those conversions and was hoping someone could help?
Another note is that I am much more knowledgeable of AC circuitry than DC. I know that my meager 60amp service panel can not have more than 60 amps being drawn from it at any one given moment in time or the master will trip and the house w/o power. I know this same concept applies to my Arduino in that no more than 20 mA per pin, or 200mA can be sourced from the Mega lest it also fails.
So I am on a quest to ascertain what I need to do to safely power and control THIS 8 channel relay board → http://www.gearbest.com/development-boards/pp_29436.html?currency=USD&gclid=CjwKEAiAlvilBRC5ueCzkpXb4kgSJADxop1BQHiCFI5PoS2Gmp2bnJDlgFy1cGucChdzfyxg1gnNwRoC4Bvw_wcB ← I guess new members can only hyperlink a single instance?
Back to the datasheet, the relay ratings are given in “nominal voltages” and “coil resistance”. Can someone please share the process one needs to find out these numbers so I can determine if my modules are plug and play, or whether other components need to first be breadboarded after an external power supply? I have accumulated several wall warts and have a 5V1A, 9V210mA, 9V1A, 12V210mA, 12V1A and a 12V2A, so I hope to at least hit the ground running as far as external power is concerned.
I also saw on another thread a suggestion to use a 12V power source and use a heat sinked 7805 regulator to decrease voltage. I was able to salvage a 7805P and a 7809P which I hope might fit the bill if that route is my only one.
Any help, or other suggestions are most welcomed. I am building a multi room hydroponics controller and will be extensive when I complete it hopefully in the next 3 years. Any info that leads me in the direction of learning what is needed to accomplish this end goal is what I ultimately seek from my world wide web.
Thank you all