Good tutorial on grounding?

[sirhcman]

Any good ones? The ones I found on arcadecontrols.com wernt very extensive to me, maybe I am overestimating ground my control panel wiring? Any help appreciated.

[SirPoonga]

For controls, all you ever need to know is what is on the ipac instructions page.
http://www.ultimarc.com/ipac2.html

[sirhcman]

Is this for jamma too because thats what I am wiring.

[SirPoonga]

Yeah? so, same thing, daisy chain the grounds,  you have the same pic in the jpac instructions.

[sirhcman]

Then what do I do with these other grounds on my jamma harness, there are a few extra?

[SirPoonga]

Ground is ground, doesn;t matter which one you go to.  Think about why you;d have more than one ground.  If you had one ground and had to wire a cabient the wires are going everywhere.  You;d have to have ONE ground wire going everywhere (monitor, cp, coin door).  With more than one ground pin you can group wires  like group  the monitor wires together with ground that gotot he monitor.

But on the pcb it is one ground.

[grafixmonkey]

if you took a continuity tester to those separate ground pins you'd find they're all on the same wire.

There are often redundant ground pins on connectors because the standard connector has more pins than the person wanted to assign to it.  (like in the Ipac-4, there are two ground pins because when all the buttons had been assigned, there were two pins left.)

[BobA]

If you are daisy chaining your grounds bring back the furthest connector to the same ground or another ground which is the same so that even a loose connection in your daisy chain will not break your ground.   It will double insure your grounds so that it will take 2 separate faults before your grounds can fail.

BobA

[Hoe]

grafixmonkey: It's a good idea to seprately ground differnt components to avoid cross talk, with out adding some resistance between grounds. That's why a lot of stuff provides multiple grounds. It wount matter on switches.

I read through TheRealBobRoberts guide and it was pretty decent about how grounding should be. He recommended grounding both sides of your ground chain like BobA did.

[grafixmonkey]

well, only if you don't wanna know about it if a connection goes bad...   Myself, I'd prefer to check the crimp and redo it, thus maybe learning how to crimp better.

Oh and crosstalk isn't gonna happen on an IPAC, and even if it does to a significant degree, it's gonna be nothing compared to the crazy switch bouncing that goes on in the circuit.  Even ignoring switch bouncing, your electromagnetic crosstalk is going to be a heck of a lot worse than anything caused by the shape of your ground wire, unless you're using wire that's too small.  And even if there is crosstalk, these signals are digital, not analog, and any crosstalk that happens falls on deaf ears cuz soon as it hits the first digital input it's completely ignored and vanishes.  

These aren't audio amps we're building.