How to add earth ground.

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    • KaPH33n wrote:

      I also have a green earth ground cable that connects all the metal frames of my devices together (transformer, power supply, monitor chassis) and goes to my outlet earth ground. This is not necessary for operation, but is a fault protection. The earth ground cable will be tied to your AC neutral line in your house, but there should be no connectivity across the isolation transformer.
      Are these the same transformer? Also, when you say no connectivity across the isolation transformer, does that mean no earth ground should be connected to it or it’s frame?
    • Report2Marty wrote:

      Are these the same transformer? Also, when you say no connectivity across the isolation transformer, does that mean no earth ground should be connected to it or it’s frame?
      yes. when you use your multimeter on your outlet it will give a low ohms reading between neutral and ground. they are essentially the same wire because they are connected in your main panel. earth ground can and should be connected to every metal chassis in your cab. also to the control panel, coin door, lighting ballast, and possibly other places.

      after you connect your input wires to your outlet power source, when you test either of the output leads of the isolation transformer there should be no direct connection to earth ground. no beep! this is the entire point of the isolation transformer. the input and output wires are the same. you can't get them mixed up. on the input put black to one side and white to the other.
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    • Report2Marty wrote:

      thanks @KaPH33n! Is it possible you can help me plot out a comprehensible earth ground loop that will prevent me from getting shocked when I go to turn the candy cab on?

      Also, is it a concern that the cab is asking for 100v and my iso and chassis will need 120V? Will this cause any potential interference? I was getting a lot of waves in my picture before. What could that have been from?

      Lastly, (sorry for all the questions.. just trying to understand all of this the best I can) the iso wires in and out have no markings or indication if one is common or one is live.... does this matter?


      Thank you so much for all your help!
      you don't need any rhyme or reason to your ground strapping. it just needs to all connect to at least one other piece. it can be as complicated of a graph as you want it to be.

      I doubt that the earth grounding is the reason you are getting shocked when you turn on your cab.

      the cab is asking for 100v but likely runs on 120v just fine. all my sega cabs are 100v cabs and I plug them right into the wall. It's kind of up to the operator if they feel like this is out of line or not. As we keep saying there's the right voltage things are supposed to run at and then there's the tolerance with which they can accept.
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    • KaPH33n wrote:

      the cab is asking for 100v but likely runs on 120v just fine.
      From the other thread it's an Atomiswave SD, and AWSD generally do not like 120v at all. The Wei-Ya PSU that it and the Vewlix share don't work well at 120v if at all, nor does the marquee lamp if it's original. Step-down's required for those.
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    • rewrite wrote:

      From the other thread it's an Atomiswave SD, and AWSD generally do not like 120v at all. The Wei-Ya PSU that it and the Vewlix share don't work well at 120v if at all, nor does the marquee lamp if it's original. Step-down's required for those.
      ok so this is sort of a problem then. because if the whole cab is expecting 100v and it doesn't have an internal transformer to get there then you need an external step down from your wall to get 100vac.

      then inside the cab there will need to be a way to get 120vac from the wall to the monitor.

      So there's a few realistic options I can see here...

      1. go find the original 100vac monitor, get everything set back to stock. use external step down from 120vac to 100vac
      2. keep the replacement 120vac monitor that requires iso transformer. use external step down to get 100vac for the cab. run separate wall power to an iso and then to your monitor. this is the 2 power cord method and not really advised.
      3. rewire the entire cab to accept 120vac input. you could use the 120 -> 100 iso transformer you already bought to do this. put both iso transformers in the bottom of the cab. use the 100v step down to power just the power supply. use the 120v 1:1 transformer to just power the monitor.

      how many watts is the weiya psu? i doubt it takes more than 1 amp 100vac which is what peter's iso transformers are rated to do?
      Woodies: Xevious, Pac-Man, Centipede, Dig Dug, Donkey Kong, Joust Cocktail, Space Invaders, Initial D3 Single, Mortal Kombat II, Zaxxon, Galaga, Space Shuttle Pinball
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      Other: Wacky Gator, Shoot the Moon, Movie Stop, Premier Crane
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    • KaPH33n wrote:

      ok so this is sort of a problem then.
      Agreed.

      Splitting this into several threads made things pretty confusing. But he has an external step-down as of the other thread. So current setup is stepping down twice before the monitor.

      I'm not sure how many watts the Wei-Ya is, looked at a couple threads with links to the product page and Wei-Ya has pulled it down? Should be a P271 IIRC.

      Option 3 seems best I think as I believe there was some glaring issue with the original monitor, which is why he's at the universal chassis that's in there now.
      On the hunt for: Dinoking, Mushiking, Love & Berry, Egret 29, and an SNK SC-25.

      Shameless plug: Rewrite's Recaps - Your monitor and PSU recapping service center
    • rewrite wrote:

      I'm not sure how many watts the Wei-Ya is, looked at a couple threads with links to the product page and Wei-Ya has pulled it down? Should be a P271 IIRC.
      Ok so i'm doing some back of the envelope math here and it actually might not work how I wanted it to. Then again he already has another step down transformer for his 100V right? Not the iso transformer but the normal wall step down. How many VA is that one? Maybe that can fit inside the cab as well?

      100VA transformer. 100V AC output. 100V * 1A = 100VA. so the isolation transformer can only output 1 amp safely.

      Watts = Volts * Amps. if the voltage is 100V and the amps is 1A... 100W = 100V * 1A. That means the transformer can only run a 100w power supply. And then to be honest you should never hit the ceilings of any ratings. So you should probably only run up to 80w devices on that iso.

      One detail I could use clarification for myself is why are transformers rated in VA and not Watts? It seems to me that they are equivalent? Maybe it's because the transformers are at "fixed voltages" so it is clearer to be represented in VA?
      Woodies: Xevious, Pac-Man, Centipede, Dig Dug, Donkey Kong, Joust Cocktail, Space Invaders, Initial D3 Single, Mortal Kombat II, Zaxxon, Galaga, Space Shuttle Pinball
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      Other: Wacky Gator, Shoot the Moon, Movie Stop, Premier Crane
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    • @rewrite Sorry for creating so much confusion with the multiple posts.. :( I didn't mean to make a mess of this. Thank you for your patience with me during this process. I greatly appreciate it.

      @KaPH33n Sorry for not providing more info. I should've done that first or directed you to the other threads. Sorry about that.

      Is it possible to put the step-down in the cab, plug the AWSD power supply into the 100v outlet of the step-down, then connect the 1:1 iso to the 120V outlet of the step-down, then the 1:1 out to the chassis? Maybe that's more output than the step-down can handle.

      I purchased a basic 16 amp 133 watt powers supply that should be coming the same day as the 1:1 iso. Should I just rewire the cab using that? I've made a mess of this whole thing. Guess I shouldn't have started messing with it. Thank you again for all your patience and advice during all this. Not really sure what to do next.
    • KaPH33n wrote:

      the normal wall step down. How many VA is that one? Maybe that can fit inside the cab as well?
      500W - No reason it can't, I have one in the bottom of my E3.

      KaPH33n wrote:

      100VA transformer. 100V AC output. 100V * 1A = 100VA. so the isolation transformer can only output 1 amp safely.

      Watts = Volts * Amps. if the voltage is 100V and the amps is 1A... 100W = 100V * 1A. That means the transformer can only run a 100w power supply. And then to be honest you should never hit the ceilings of any ratings. So you should probably only run up to 80w devices on that iso.
      So it likely can't even run the monitor it was bought for, in that case, yeah?

      KaPH33n wrote:

      Maybe it's because the transformers are at "fixed voltages" so it is clearer to be represented in VA?
      Most reasonable assumption I can come up with.

      Report2Marty wrote:

      Sorry for creating so much confusion with the multiple posts.. I didn't mean to make a mess of this.
      Nothing to worry about!
      On the hunt for: Dinoking, Mushiking, Love & Berry, Egret 29, and an SNK SC-25.

      Shameless plug: Rewrite's Recaps - Your monitor and PSU recapping service center
    • Dont forget that those iso transformers are also rated at 100va so whatever load you put on them shouldn't draw more than 1amp. Havent read the whole thread though, looks like there are quite gew things being asked besides just earth ground though.


      Wanted: PCBs - Batsugun, Battle Garegga, Battle Bakraid
      Other stuff - 19" Monitor/chassis and/or WG K7000 Chassis
      Vewlix Shipping Brackets (2x sets of the red ones would be nice)
      High End Headphones/Desktop Headphone Amps/DACs as well.
      If you have any of these for sale/trade let me know :thumbup:
    • Looking through all this, its looks like you are not earth grounding stuff properly.
      There should be no need earth ground the iso xfmer frame/casing, crt metal frame as far as Im aware.

      The PSU needs a 100v stepdown transformer, even is it says +/-15V I would still use a stepdown.

      Your chassis needs an iso transformer as has been stated. You mentioned in needed to be 120v on the secondary?? From what I read it should be 110v but I know most of these have an operating range/tolerance, so it should be fine. The secondary on the iso doesn't have a hot/line side, think of it as its own power loop, so it doesn't matter how it connects to the chassis.

      The grounding screw on the plywood, one with the green/yellow wire is not grounding anything (it might be a ground wire connected to the cab frame on the other end, in that case you can attached other wired to it to earth ground those points. The black wire attached to the plywood, is that a grounding point going somewhere? If so that most likely needs to attach to the yellow/green wire ground. You can test that all you ground points are good with continuity test/ohm measurement. Also, if those screws actually reach/screw down into the metal frame of the cab then you should be good on those points being earth ground.

      Good transformers whether iso or auto are expensive. If you can get someone to give/sell you one a 120-100 stepdown like a Sega cab i would grab one of those to use with your psu. Get the correct ISO for your chassis and you should be good to go. As far as wiring is concerned, when you have all your parts in hand post up if you have problems wiring it all up. Also, I would leave the power strip that came with the cab, it was wired properly. You can install a plug on your iso transformer leads to plug there.


      Wanted: PCBs - Batsugun, Battle Garegga, Battle Bakraid
      Other stuff - 19" Monitor/chassis and/or WG K7000 Chassis
      Vewlix Shipping Brackets (2x sets of the red ones would be nice)
      High End Headphones/Desktop Headphone Amps/DACs as well.
      If you have any of these for sale/trade let me know :thumbup:

      The post was edited 1 time, last by Derick2k ().

    • How is this coming along? Ever figure out a plan for your 120v vs 100v issues?

      If you still need isolation transformers here's the deal of the day!
      forums.arcade-museum.com/showthread.php?t=472332

      I have bought a few things from this guy, he ships quick and is very responsive.
      Woodies: Xevious, Pac-Man, Centipede, Dig Dug, Donkey Kong, Joust Cocktail, Space Invaders, Initial D3 Single, Mortal Kombat II, Zaxxon, Galaga, Space Shuttle Pinball
      Candies: 2x Aero City, New Astro City, 2x Blast City, Net City
      Other: Wacky Gator, Shoot the Moon, Movie Stop, Premier Crane
      VAPS