Do monitors need a power converter?

[JayTea]

     Can I run 110 directly to the monitor, or do I need to go through a power supply specially designed?  I ask this because my linear power supply is shot.
     The guy before me ran the PCBs, sound, and controllers off of an after market AC -> DC power supply (still working)and ran a splitter from the main (power from wall) to the original linear power supply to run the marquee and monitor.  I'm assuming he did this because they take 110 AC volts?  If this is the case can I just run 110 straight to the monitor and marquee (with an on/off switch, of course)?

     Any help or comments are greatly appreciated!

JT

[rampy]

I assume you are talking about an arcade monitor...

in that case... it varies.  Some arcade monitors REQUIRE an isolation transformer between themselves and 110v... others don't.

Beyond that, I'm not much help (as per usual)... hopefully someone else will chime in... but maybe you could provide more specifics to your particular monitor model.

rampy

[JayTea]

It's an Electrohom 19" GO7 series, circa 1984.  It says 120 v AC on the chassis, but I'd like to know for sure - I don't need a bright light and explosion in my garage

[MameFan]

I'll clarify rampy's statement.

MOST "classic" game monitors (e.g. 1990 and before for the sake of this discussion) **ABSOLUTELY REQUIRE** what's called an "Isolation Transformer".  Newer ones may or may not require.

The thing is, with so many game converted time and again, you can never assume anything as a new game may have an old monitor and an old game may have a new monitor.

In any case, your Electrohome G07 most DEFINITELY requires an isolation transformer.

If you plug it into the wall, THEN plug in and power up your gameboard, you will be treated to wonderful sparks and burning of both the monitor board AND gameboard.. You will toast it well.


Basically, if in doubt, ALWAYS connect an isolation transformer. Using one when it's not needed never hurts anything. The opposite however can and will destroy things if one is not used when it is needed.


(If you know electronic components, you *usually* can tell by looking at the power section right after the AC cord connects to see if it includes its own isolation or not, but never guess)

Note: Most games I've seen have 2 power supplies. One is the isolation transformer (and only goes to the monitor typically), and the other is a linear transformer that goes either directly to the gameboard or to a daughter board to stabilize the power then onto the game board.  Therefore if you say your linear power supply is shot, did you at least have the linear isolation transformer still working to connect to?

Otherwise take one out of another machine or you can buy them from bobroberts for around $10 a piece (plus a chunk of shipping of course since he only ships via expensive priority mail)

[tom61]

If you plug it into the wall, THEN plug in and power up your gameboard, you will be treated to wonderful sparks and burning of both the monitor board AND gameboard.. You will toast it well.

Actually the chance is 50/50 that it will blow. Monitors are polarised.

MOST "classic" game monitors (e.g. 1990 and before for the sake of this discussion) **ABSOLUTELY REQUIRE** what's called an "Isolation Transformer".  Newer ones may or may not require.

The only exception is Nintendo monitors which require 100Volts from a transformer.

[JayTea]

I'll test the transformer seperately...it was hooked up to the linear power supply, therefore it wasn't getting any power running through it.  I will hook up power directly to it and see if I get a reading on the other side.  Is there an ohm / voltage reading I should be looking for?

[MameFan]

The isolation transformer will typically be the smaller transformer (separate from the linear ps one that has many outputs and bigger).

It should only have 2 inputs and 2 outputs (plus a ground on the frame)

It should show 0V and 115V on the pins, 0 should be the white "neutral" wire and 115v should be the black "hot" wire (if traced back to the wall) on the non isolated side.

Do not set your meter to ohms if it's on..you'll likely fry it. Set it to AC 75-200 volt setting and test against the 0V and 115V  on the isolated side and you should get 115 volts +/- 5 volts.

[JayTea]

     I apparently have an old transformer block... A big 4" x 4" block.  I will be able to offer more info when I get home from work today.  Thanks for the meter readings/directions mamefan!

JT

[JoyMonkey]

I bought one of these isolation transformers on eBay a couple of weeks ago and finally got my old Popeye monitor working (yay!).  

There's one going right now for $11 + $8 S&H:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3217558264&category=13718

It's pretty small and works great. Seems like its never been used before.

[MameFan]

You can get the exact same one from BobRoberts for $12 and I believe $6 shipping (unless it pushes it to the next pound), plus of course get your other stuff from him too

See the transformer in this pic from his web site.. Looks identical to me, down to the label: http://www.dameon.net/BBBB/iso.html