Author Topic: Power supply for DMD  (Read 2445 times)

Steve S

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Power supply for DMD
« on: February 06, 2010, 03:13:34 PM »
I'm putting together parts for my homebrew machine, based on a WPC platform.  I bought a Stern display power supply, part 520-5138-00 (schematics at http://www.sternpinball.com/downloads/SHREK_SGM/SHREK_SEC5_CHP4_PT4_DPS.pdf).  It seemed a more cost effective solution than buying a WPC display controller board (schematics on page 11 of http://www.pinrepair.com/wpc/wpc-s.pdf) just to use the power section.  However, I can't figure out how to connect it to the WPC transformer outputs for the AC voltages.  The WPC system used two wires each for the 80 VAC and 110 VAC circuits to the dot matrix controller board, while the Stern board only uses a single wire for its 88 VAC and 110 VAC inputs.  The Stern board has an "XFRMR_GND" input line, which I'm guessing is used for the second path for both AC voltages, but I don't know much about AC other than plugging stuff into the wall.

Can someone help me out?  Thanks.

--Steve

Gerry Stellenberg

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Re: Power supply for DMD
« Reply #1 on: February 06, 2010, 03:40:52 PM »
Steve,

Stern uses a center tap transformer to produce the two voltages while WPC uses two separate transformers, hence the wiring difference.  I *think* you can connect a Stern transformer to a WPC dmd controller using the center tap with both segments, but I have no idea if you can do what you want, which is the opposite.  My guess is no, but I'd recommend getting an answer from somebody who knows more about transformers, perhaps ask on rec.games.pinball.  There are a bunch of electronics gurus there.

-  Gerry

Steven

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Re: Power supply for DMD
« Reply #2 on: February 08, 2010, 06:09:28 AM »
I'm sorry, can't help you, but IF I'd build an own pinball, I think I'd use a LED DMD, so you wouldn't need the High Voltage. Good luck with your project! Please keep us informed of the progress!

Steve S

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Re: Power supply for DMD
« Reply #3 on: February 08, 2010, 07:47:03 AM »
I'm returning the Stern board - I've got a bid on eBay for a replacement WPC display controller, and if I don't win, I'll think about using the LED display.  It would be a cleaner, although much more expensive, solution.  I've already got a spare DMD display that I was going to use, which would save a few dollars.  The lowest price I've seen for the LED dot matrix displays is about $270, making a new plasma display and controller board less expensive then the LED alternative.

If anyone knows of a less expensive source for the LED display, please let me know.

Steven

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Re: Power supply for DMD
« Reply #4 on: February 08, 2010, 11:10:21 AM »
Hmmm... that's quite a lot of money. I was lucky to get one second hand.
Here's one that's a bit less expensive: http://cgi.ebay.com/Bally-Williams-Pinball-PinLED-128x32-Dotmatrix-Display_W0QQitemZ330325154213QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item4ce8e9d9a5

220 dollars instead of 270.

I don't know how the P-ROC looks with led vs plasma. I think a lot of people like the 'plasma look' better.

And maybe you can find a WPC display controller with a working HV section, but with a failing logic section. Might be worth the trouble posting on rgp for.

russdx

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Re: Power supply for DMD
« Reply #5 on: February 08, 2010, 12:45:22 PM »
you can also buy dmd displays with built in dc power supply ($150 extra though) but is very handy as you now just need to give the display 12v 3amp and the other 6ttl signals and its happy :)

bought a 192x64 version my self and it runs of a normal pc power supply perfectly (even has the same connector hehe)

http://gb.mouser.com/Vishay/Optoelectronics/Displays/Plasma-Displays/_/N-6j73cZ1z0zls5?P=1z0znyk&FS=True



Steve S

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Re: Power supply for DMD
« Reply #6 on: February 09, 2010, 06:26:22 PM »
I ordered one of the Pinled LCD displays for $220 from eBay.   More than I was hoping to spend, but it's less than if I had to buy a new plasma display and controller board (it's a stretch, but that's the rationalization).  Thanks for all of the suggestions.