Build Your Own Arcade Controls Forum
Main => Monitor/Video Forum => Topic started by: tenex2mg on February 18, 2004, 06:41:37 pm
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Greets All,
Well I picked up an arcade monitor off ebay (item #3073636001). Turns out its a WG 25k7194, apparently its a Zenith. Anyways, I just got my Arcade VGA card/VGA cord, that's no problem. What I'm having some difficulty trying to figure out is how to supply power to this particular monitor?
I picked up an isolation transformer from betson/imperial (they are two towns away...big sticker on monitor proclaims its neccessity). Basically all that's coming out of the monitor are the two wires that would attatch to the iso-transformer. I think there's a "ground" screwed into the chasis with no wire attached to it. This is located directly in front of where I'd connect the video pin-outs.
I'm trying to follow oscar's diagram (post: Re:How to power monitor with no PCB
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Greets again,
I was just at the Ultimarc website just double checking a few things..here's a quote...
"Why do some arcade monitors need isolating transformers?
The reason for this is mainly historical. When the first video games came out, they used modified TVs. "Computer Space" (the first) actually used a real TV with Valves (vacuum tubes!). Then some manufacturers started to produce monitors which were basically TVs with the RF and IF stages taken out. The problem was, old TVs all had "live" chassis, in which the metal frame was connected to one side of the mains supply, and insulated from the outside world by the casing. This simplified the design of the power supply (sometimes it was just a big resistor which got very hot!). This was fine as long as nothing was ever plugged into the TV (except the aerial (antenna) which could easily be isolated using a capacitor). But when games came out, there was a need to connect a game board, and also safety issues which meant the chassis had to be no longer connected to mains, but to safety ground, hence the need for a transformer. No currently produced monitors use these. If your monitor has a transformer DO NOT WIRE IT OUT as the monitor chassis will be live, and cause major dangers not only for safety but instantly destroy anything connected to it. "
Does this mean that if I do have an isolating transformer I don't ground out the chasis as seen in oscar's diagram?" Or do I?