I have this relay board its basically plugs into the printer board and acts like a switch IT HAS NO(Normally open),NC(normally close), and (common)
And i have this another board This board Doesnt have to do anything to do with computer . It has its OWN remote controll.,But it still has NO(Normally open),NC(normally close), and (common)
https://www.mpja.com/productview.asp?product=6072+KT
Now what i want to do is use a 8 extra relay so this boards will act like switchs I want to know how to wire this both things up only using one relay on each channel(or in other word one relay to each channel connecting to both the boards and can turn stuff on and off.
sorry i never responed i couldent figure out what you ment. I think i get it now. You want to use the boards to switch the same relays, either board will switch them? Is that it? So that say you hook a light to one relay, you want it to be able to be turned on with either board? Either the remote or the computer? Im not sure if thats what you mean....
If that it what you want, you can just tie the common from each relay on each board to +12V, then just connect together the outputs from each channel on each board. Say if each board has a channel 1, on each board. Hook the common from the 2 relays to +12V, then hook the NO from each relay (both channel 1) together. you dont need a diode because they are just relays.
I hope that is what you ment, if not correct me.
You got what i want to do..... sorry for all the misunderstanding.. so then to wire up to relay i would do the chart i have at the bottom right?.. ANd you know how i have common on both the board and there is eight channel on each so that mean i have to have 16 wire that are 12+ right?? or should i just jump the common wire?meaning common to common so that way i only have to run one power wire to each board .. You think its going to be safe doing that?
Common from relays board: +12V
NO of relay board: Terminal 85 of standard automotive relay
Terminal 86 of automotive relay: Ground (-)
Terminal 30 of automotive relay: High current +12V
Terminal 87: Output to fog lights and such
Yea just jump all the commons together and then to +12 V, they are only driving relay coils so there is not much current draw. then run both channel 1 wires the NO output (2 of them) together and to an auto relay, terminal 85. then terminal 86 to ground, then you have your relay to switch stuff on, you just have to do it for each channel. Good luck, let me know how it turns out.