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Grounding a USB trackball necessary?
DaveMMR:
--- Quote ---Couldn't you make a simple contact point on your panel where it attaches to the cab ? Like the contacts used in old (e.g. before magnetic contacts) alarm systems to detect if a window or door is open. The panel side would connect to the earth ground on your TB while the cab side would connect to an earth ground in your cabinet.
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Yeah I was thinking about doing something like that. It doesn't have to be something complex - maybe just two metal contacts. Static Electricity is not a big problem around here though, so I'm not going to sweat it too much either.
u_rebelscum:
AFAIK, the ground on the TB is to ground the rollers'/ball's static build up from arcing to the sensors. It is NOT to directly ground you. Static can tranfer from you to ball to roller, but won't be fast (in electronics speeds, that ball isn't a good conducter after all). However if the static on the roller isn't discharged with a wire, it can build up and in rare cases damage the sensors. Add that the ball rubbing on the roller (and you touching the ball) can cause static build up and ... it might build enough to zap.
BTW, I don't hook up my TB ground, but it's not cold nor dry enough here most of the time. ;)
2600:
--- Quote from: u_rebelscum on June 07, 2006, 02:29:04 pm ---AFAIK, the ground on the TB is to ground the rollers'/ball's static build up from arcing to the sensors. It is NOT to directly ground you. Static can tranfer from you to ball to roller, but won't be fast (in electronics speeds, that ball isn't a good conducter after all). However if the static on the roller isn't discharged with a wire, it can build up and in rare cases damage the sensors. Add that the ball rubbing on the roller (and you touching the ball) can cause static build up and ... it might build enough to zap.
BTW, I don't hook up my TB ground, but it's not cold nor dry enough here most of the time. ;)
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That's what I've always heard and I can't argue with that, but don't forget about the trackball mounting plate. It's been a long time since I've looked at a trackball taken apart and looked how, but it get's grounded through the ground wires as well.
Like I said, I'm think I'm the minority in saying to use them. But search the forums, every once in a while someone will say I touched my spinner and my PC died. It's not often, but it happens. If you live in area where you don't shock someone, maybe you don't need to. I've always lived in an area where it happens.
Plus aren't all metal objects in a real arcade machine grounded. ;)
Fozzy The Bear:
As has been pointed out.... Signal ground and earth ground are two different things......
Earth Ground: Grounds all metal components so that any dangerous voltages which can occur during a mains power short circuit, are carried away to Earth through the green wire and not through the person who comes into contact with them.
Signal Ground: In most cases deals with Low DC Voltages and is just the return path for the signal. Mostly it's not really a true ground but just connects to the negative rail of the supply. It's effectively at a floating voltage, and not 0V "True Ground".
SO!! If you have a metal CP then you should definitely connect the green wire to the earth connection (grounding tag) of the mains supply or to the panel which should have a grounding wire so connected, for safety reasons.
Best Regards,
Julian (Fozzy The Bear)
Ninten-doh:
Thanks for all the info guys! What I still don't get is why a normal USB trackball mouse used for Windows, etc. can simply be plugged into a PC, but an arcade trackball needs the grounding. Is the key to all this what Fozzy just said...
"If you have a metal CP..."
Since the normal trackball mouse is encased in plastic it doesn't need the ground, but if the arcade trackball is attached to metal it needs the ground?