Build Your Own Arcade Controls Forum
Software Support => GroovyMAME => Topic started by: abispac on March 18, 2020, 10:19:46 am
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Im sorry for the double post, but i dont get a responce on the monitor video forum so i though ill as here, anyway.
Hey so im trying to use an old 19 crt monitor i had laying around. It was working fine, but, stupid me, when i gutted the old cabinet , i discarded the isolation transformer thinking it wasnt any good. So long story short, when i was about to try my pc in the monitor, i pluged the monitor directly to the wall socket and it worked for like 3 minutes, so, i disconected it, plugged back in , and it didnt work. So i took the monitor with a friend of mine, and he said one of the horizontal oulets gave more power and ---fouled up beyond all recognition--- the monitor, plus all caps where dry. He fixed the monitor but i have not plugged it back in as i do not want to ---fouled up beyond all recognition--- it up again, so i guess my questions are, #1 its really not a way to hook this monitors directly? if not, how can i know what kind of isolator do i need? thanks in advance for any help.
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Oh dude...
:dunno "Yawn, what's this seemingly useless metal lump in the corner?"
"Hmm, looks completely boring yet is wired in... a bit heavy... Let's remove it and chuck it away!" :bump
Yeah you need the iso transformer for many monitors, especially older ones. Running the monitor without it will damage monitor components, sometimes in a dramatic way. Did you see any "magic smoke" come out? :blowup:
Mike A already posted a link on the monitor forum:
https://www.arcadepartsandrepair.com/store/cabinet-parts/power-supplies/monitor-isolation-transformer-120v-output/
If you want anything more specific you will need to quote monitor/chassis type. If you don't know, then good photos help especially of markings.
The isolation transformer literally "isolates" your monitor's power supply from the mains. It transfers mains power to the monitor via electromagnetic inductance between two sets of tightly turned copper wire. There is no physical connection between mains and monitor sides.
This means that although there are only two wires coming out with AC ("active/neutral"), you have effectively made a local ground as well. The electricity would prefer to "ground" itself in it's own circuit than through something else (like you). This makes it safer than mains power, which might prefer to ground itself THROUGH YOU rather than the electricity substation a kilometre down the road.
To complicate things, many isolation transformers also act as step-down transformers, adjusting voltage. Some monitors are fussy about their voltage. Also be aware that not all step-down transformers are isolation transformers. I've been told "Yeah this step-down tranny is also an ISO", only to stick my multimeter probes into opposite sides and get continuity (ISOs sides aren't connected).
Anyway, you do need to specify what monitor you have, on the Monitor/Video branch, in order to get the right advice.
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Thanks, yeas i got a responce on the monitor forum, will follow up there, thanks for the help.