Omega Race Power Supply Questions

[Necro]

Not sure where to post this (here, misc, or what), but I put a picture of this up in my project thread and didn't get any responses and wanted to try a dedicated thread since not everyone checks projects. 

In my cab was this board:


What I THINK it is is a transformer of some type to convert the 110V AC coming out of the wall into a variety of DC voltages.  At least, that's the big block on the left.  There's a filter on there and another block (the one on the right) that I have no idea what it is.  Also, there's these two large battery things (top left corner) that I think are some kind of capacitors...but I don't know how I could use them or how dangerous they are.

I have a multimeter that I acquired a ways back, but I really have limited electronics knowledge past what I learned in Physics in college (the theory behind current, voltage, etc.)...so I'm not sure what's safe to test, what will blow up my multimeter if I connect it, what I should be testing, what's safe to plug in since it's not connected to anything, if because it's not connected to anything means it wouldn't test right anyway, etc.

I'd LIKE to use this to power my flourescent lights and provide the 12v and other DC voltages to the cab so I could leave the lights on without the computer being on if I wanted. 

TIA to anyone that can give some insight and/or recommend a good electronics reference/tutorial.

(Edited title to allow for this thread to be found via search)

[Turnarcades]

Isn't there a much simpler 'off the shelf' solution without using a beat-up old part that's had loads of use and may not work properly anyway?

I don't like taking chances when it comes to electronics and the risk of fires/shocks/component damage.

[ratzz]

I'd have to agree with Craig -- it looks pretty shot to me, and there is no point risking all for a solution that may cost little money.

I got a couple of shocks working on a TFT recently (unplugged, and left alone for a while --- must have been capacitors stored energy), not very bad, but enough for me to think about a bought in solution as opposed to trying to save a few quid.

[RayB]

I'm not sure that's a DC power supply, it's the main AC "block". Power comes in from the wall, there should be an AC switch somewhere in there... One of the big blocks there is the isolation transformer for the monitor. There are fuses there for safety and the little silver box is an AC filter.

It doesn't look "shot" to me AT ALL. Just dirty as hell. Clean it. Damp rag, soft paint brush... you'll be surprised how good it looks after.

[ratzz]

Damp rag,

Hmm, damp rag and electronics (101) ...

Hey give it a go, you never now your luck in a raffle! 

[Ken Layton]

Appears to be the complete AC power section of a Domino Man-ish vintage Midway video arcade game. There are TWO power transformers mounted on it. In the upper left corner of your picture is the filter capacitor bank which would have fed filtered raw DC to a power supply circuit board.

[RayB]

Hmm, damp rag and electronics (101) ...

If you're dumb enough to do it with the thing plugged in, then you get what you deserve. If you're dumb enough to use a WET rag that will get water into everything, and then go and plug it in, you get what you deserve.

I bet you're unaware that people commonly put entire circuit boards in THE DISHWASHER to clean them?

[ratzz]

Hmm, damp rag and electronics (101) ...

If you're dumb enough to do it with the thing plugged in, then you get what you deserve. If you're dumb enough to use a WET rag that will get water into everything, and then go and plug it in, you get what you deserve.

I bet you're unaware that people commonly put entire circuit boards in THE DISHWASHER to clean them?

Well, Ray, I'm glad you are giving the professional advice on this. Me? I'd scrap it and buy a power supply off the shelf. Nice, clean, and post "damp clothed" cleaned.

I'm not unaware that people use "THE DISHWASHER" to clean components (not sure why you keep CAPITALISING STUFF) -- so, put the PSU in the dishwasher! Ray said so!

I think you have to allow a little common sense when dealing with high voltage, and unless Charles Babbage built it, scrap it and use something reliable and new.

Me ... I have a wife and daughter, and I'd just but a new £10 PSU...

BTW. The PSU on my TFT (as I said) was unplugged and had not been plugged in for some while. Even so, I got a couple of jolts up my arm that convinced me that if I didn't know what I was doing, to stay well clear.

[Kevin Mullins]

-- so, put the PSU in the dishwasher! Ray said so!

I would .... the key is in the drying.   

I've thrown pcb's, monitor chassis, harnesses, joysticks, buttons, you name it and I have probably had one in the dishwasher before.
Just be sure to blow out any excess water trapped in the nooks and crannys and then throw it out in the sun for awhile.

[Necro]

I took that picture before I vacuumed it off with a brush attachment.  it actually looks 100x better without all the crud on it.

Ok, I knew the one in the lower right corner was some kind of power transformer.  I just wasn't sure exactly how to test it to determine exactly what it was.  The one on the right...I have no idea. 

This is from an Omega Race, so Ken was dead on. 

There's no 'on light' or anything like that, and it doesn't explode when I plug it in and hit the switch (this is wired into the cabs power switch with the switchin inline on the 110v line in which I believe goes to both the flourescent lights in the cab...which I haven't been able to get working either even after attempting to wire them directly to the power cord .

[SirPeale]

There's nothing wrong with using  a *damp* cloth to wipe down electronics.  As Kevin said, the key is in the drying.

With a transformer block like that you're not even talking about high voltage.  And after drying anything that's going to happen will happen right when you plug it in, inside the cabinet.

Have you seen my A/R II cleanup?   I sure as heck didn't do that with just a brush.

[CheffoJeffo]

Even so, I got a couple of jolts up my arm that convinced me that if I didn't know what I was doing, to stay well clear.

Right, so we should take *your* advice seriously ?

I am kidding.

When I first started out, I pulled what I termed a "boat anchor" power supply out of a Galaga cabinet and replaced it with a switcher. It was the right thing for me to do at the time (because I didn't know what I was doing), but I am really glad that I kept that boat anchor.

Too often people say things like "new and reliable" to describe switching power supplies, when what they really mean is "new and I understand how to use it".  The 30+ year old power supplies I have seem to be, in my experience, more reliable than new switchers (evidence is anecdotal, but I haven't had an "old" PS fail and have had switchers fail).

I have switcher conversion kits for my Galaga, Joust and Tron. I'm still working on boards for Tron, so I'm not using any PS yet. Joust runs on the old "unreliable" linear power supply. Galaga will be back running on the boat anchor once I clean the block up (and the one I have from an Atari Football that I'll be doing at the same time), hopefully to somewhere near BrentRadio and Peale's standards.

I think that those who haven't actually used the "old" supplies should refrain from implying that they are anything other than "old" in their responses. I have no issue with people doing what makes them comfortable (and, in fact, recommend it), but saying stuff like "more reliable" when you really don't know what you are talking about is sheddy.

But then, I'm a grumpy old man.

[Necro]

So...anyone have any advice on how to test this to confirm it's working properly, etc.?  Any thoughts/info on wiring up fluorescent lights would also be appreciated.

[Necro]

WOOOOO-HOOOO!

Ok, I figured out the issue with the AC power to the fluorescent lights - seems there's a switch somewhere that I disconnected and wasn't paying attention.  I saw two quick disconnects and realized that they were in one of the wires that SHOULD be the live wire to the fluorescent light plugs.

One down, one to go.  So, now that juice is going to the transformer properly...

There's a bunch of labels all over the transformer for various voltages.  I think one side is the AC input, the other is the DC output....unfortunately, not totally sure how to figure out what's what. Some of the output voltages are odd also (3.16, 0.4, etc.)  And I can't understand where the heck the 12v for the smaller lights on the cab came from...

Any thoughts/ideas would be appreciated.

[Necro]

Appears to be the complete AC power section of a Domino Man-ish vintage Midway video arcade game. There are TWO power transformers mounted on it. In the upper left corner of your picture is the filter capacitor bank which would have fed filtered raw DC to a power supply circuit board.

Just as an update to whomever finds this, I went through the schematics for a bit trying to figure out how to get 12V out of this, and this is bang on.  It seems the only way to get 12V (or any DC) out of this setup is to rig the entire thing, with the linear power board, up and use the outputs off the linear power board.  Definitely not worth it for a MAME cabinet since (depending on power needs) one can just use the 12v rail off of the PSU to power LEDs and the like if necessary.

I guess I'm going to have to wire up the AC to the flourescent's completely seperately.  To keep this thread clean and just on this topic, I'll post my other electrical/wiring questions elsewhere.