Fuses, Filters, and NOT electicuting myself while building a Supergun

Blur2040

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I'm knee...er...ankle deep in building a Supergun...

I have myself an arcade power supply...an AC line Filter (the kind that takes a PC power cord) and a fuse holder/fuse and a nice power switch to control it all.

My only issue that I have is that every wiring diagram I see (OK, the only wiring diagram I see at therealbobroberts.net) tells me suggests that I place a fuse BEFORE the line filter on the hot line, then the line filter, then a power switch on the hot line.

The snag I hit, is that for the sake of neatness, my line filter is a surface mounting one that takes a PC power cord on one end...meaning I can't place a fuse before the power line filter. So...instead...I'd just place it afterwards...so it would still protect my power supply and game boards.

Now, I as I understand it, the Line filter attempts to stabilize voltages, and the fuse stops power from coming through (blows) if too much amperage (depending on the fuse) is coming in. So...I don't think my proposed change would be a problem...but if somebody could better explain why this does or does not work, I'd appreciate it.

The big question is: Does my proposed placement of a fuse (I know some people will tell me I don't need one...or the line filter...)have any negative effect?

I guess this question might sound stupid, but I'm absolutely anal about safety and neatness of my work.
 

BIG BEAR

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AC Power Cord to the Line Filter. All three connections run into the line filter. The nuetral connection goes from the Filter straight to the supply. The ground stops at the filter. The hot connection should goto the switch,then link to the fuse and then the fuse should link to the supply.
BB
 

Blur2040

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I don't have to worry about connecting the ground line off the filter to the power supply then?...or grounding to the power switch? Why?

(I'm much more confused about not hooking up the grounding for the power supply to the grounding that comes in from the wall.)
 

SSS

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basic-ac.gif



Obviously you'd leave out the Iso Trans and power distro block. But essentially a supergun is the same crap inside a cab.
 

Blur2040

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Yeah, thats the Diagram I've looked at...it didn't take me long to figure out that I didn't need the isolation transformer (no monitor) and the distribution block (only connecting AC to the power suppy)...and well, the part BIG BEAR said about leaving the fuse after the power switch (as opposed to before, as in the diagram) makes sense to me, as I don't think I've ever encountered an arcade device that has a fuse before the power switch...(though I might be crazy/have a horrible memory)

The part I'm still a bit hazy on is the grounding. I know in a cabinet, you'd have every hunk of metal connected together and to the ground from the wall...but I guess I'd like to know why I wouldn't connect the ground from the line filter to the ground on my power supply.
 

SSS

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Blur2040 said:
wall...but I guess I'd like to know why I wouldn't connect the ground from the line filter to the ground on my power supply.

you would
 

BIG BEAR

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The fuse along with the switch should be placed on the other side(HOT) of the filter. The FRAME GROUND(FG) doesn't need to be attached to the supply. The grounding connection to the filter takes care of the (FG).
According to that diagram, the fuse should be place right between the switch and the power distribution block.
BB

Blur2040 said:
Yeah, thats the Diagram I've looked at...it didn't take me long to figure out that I didn't need the isolation transformer (no monitor) and the distribution block (only connecting AC to the power suppy)...and well, the part BIG BEAR said about leaving the fuse after the power switch (as opposed to before, as in the diagram) makes sense to me, as I don't think I've ever encountered an arcade device that has a fuse before the power switch...(though I might be crazy/have a horrible memory)

The part I'm still a bit hazy on is the grounding. I know in a cabinet, you'd have every hunk of metal connected together and to the ground from the wall...but I guess I'd like to know why I wouldn't connect the ground from the line filter to the ground on my power supply.
 
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jwyder

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I have a Suzo Happ 130w +5v 15A, +12v 4A, -5v 1A power supply. I am trying to figure out what current rating the fuse should be for the AC Line to be placed between the power cord and the switch (then to the power supply). I have read 5A and 6A and some I have seen at 3A. None have explained why one is better than the other. What would the recommended current rating for the fuse?

Thanks
 

jwyder

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I contacted Suzo Happ and this was the reply:

"These power supplies have an internal fuse in line with the AC line in.
It should not be required to add an external fuse to this.

If you really would like to do this as an added precautionary measure use a 5A slo-blo fuse."

So I hope this helps someone else looking for this information since it took me a while to find the correct answer.
 

jwyder

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Hey Xian Xi, that's what Suzo Happ USA support stated. I see you have built a bunch of superguns, when adding a external fuse to the AC Line what have you been using? Is there a better recommendation?

Inside the power supply is a 4A 250V 5mm x 20mm and it looks like it is a fast burn fuse.

I am building my first supergun and I have searched this site and many others without a clear answer (unless I am not searching for the right information). I posted here because this seems to be the most technical site and I have learned a TON from!!! Most questions have been answered by searching and seeing what others have done here.
 

SNKorSWM

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Sounds like some sort of adult toy rather than a fuse. XD
 

Xian Xi

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Hey Xian Xi, that's what Suzo Happ USA support stated. I see you have built a bunch of superguns, when adding a external fuse to the AC Line what have you been using? Is there a better recommendation?

Inside the power supply is a 4A 250V 5mm x 20mm and it looks like it is a fast burn fuse.

I am building my first supergun and I have searched this site and many others without a clear answer (unless I am not searching for the right information). I posted here because this seems to be the most technical site and I have learned a TON from!!! Most questions have been answered by searching and seeing what others have done here.

The way I do mine is is I use a multimeter to check how much the power supply pulls at start up. The power supply I use has an internal 3A fuse, on startup it pulls 2.3A so my external one is a 2.5A one. I use fast blow, I don't want to use slow blow and then need to change the internal one.
 

jwyder

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Xian Xi thanks for the feedback. Looks logical. I will get out the multimeter when I get back from my travels and see what it measures. I thought the Slow-blo did not look right. Thanks!!
 
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