Isolation transformer needed for test?

Aniraf

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The need for an isolation transformer is related to using a CRT monitor that requires one. (Not all CRT monitors require one.)

These both looks like suit case jamma rigs. (Or I missed the mame part if it is mame.)

Since I saw an LCD screen in one of the pictures (I looked real fast), no, you don't need an isolation transformer.

You would only need it if you have an arcade monitor typically made in the 1990s or older.

If you are using a TV with a built in input, you don't need one. If you want to modify a CRT TV to add an input, you might need one.
 
So, power goes from the power supply, to the isolation transformer, the to the 115vac monitor input?
 
So, power goes from the power supply, to the isolation transformer, the to the 115vac monitor input?

No.

A/C input goes to the power supply (D/C output of 5v/12v/-5v/etc)
A/C input would also got to the monitor (isolation transformer in between if needed)

These are wired in parallel.

What monitor do you want to used?
 
If you are ever going to test Nintendo (20EZ), etc... and need 100V... you can take a Nintendo isolation transformer from a Mario, DK, DKJr, etc. Normally you feed your 115/120 in and get 100V out. However, there is 100V in tap. If you put the power in there you'll get your 115/120 back out (isolated of course) for non 20EZ setups.

So you can use a SPDT (single pole double throw) switch to send your AC hot side into the common on the switch. Send one of the poles the normal 115/120V input and the other to 100V input. Then measure your output (with no load), and label your switch. Now you can support testing/powering 20EZ and other 100V monitors as well as G07, etc.
 
If you are ever going to test Nintendo (20EZ), etc... and need 100V... you can take a Nintendo isolation transformer from a Mario, DK, DKJr, etc. Normally you feed your 115/120 in and get 100V out. However, there is 100V in tap. If you put the power in there you'll get your 115/120 back out (isolated of course) for non 20EZ setups.

So you can use a SPDT (single pole double throw) switch to send your AC hot side into the common on the switch. Send one of the poles the normal 115/120V input and the other to 100V input. Then measure your output (with no load), and label your switch. Now you can support testing/powering 20EZ and other 100V monitors as well as G07, etc.

This is also good information. WTF kind of lunatic would have developed a 100vac monitor? Crazy!
 
This is also good information. WTF kind of lunatic would have developed a 100vac monitor? Crazy!

The Japanese - that's their standard AC voltage.
Just like Europe (etc) runs off 220VAC. And get this, it's 50Hz and not 60Hz. Crazy stuff.
Wow, there's a big world out there ... :rolleyes: ... lots to learn.
 
The Japanese - that's their standard AC voltage.
Just like Europe (etc) runs off 220VAC. And get this, it's 50Hz and not 60Hz. Crazy stuff.
Wow, there's a big world out there ... :rolleyes: ... lots to learn.

With every passing day in this hobby, I smack myself for not becoming an electrical engineer. On the flip side, I'm learning a hell of a lot of cool stuff about electrical engineering!

I knew about the EU, but I didn't know about Japan! I guess I never really thought about it :/.
 
With every passing day in this hobby, I smack myself for not becoming an electrical engineer. On the flip side, I'm learning a hell of a lot of cool stuff about electrical engineering!

I knew about the EU, but I didn't know about Japan! I guess I never really thought about it :/.

I'm not an electrical engineer. I fix games.

The Japanese - that's their standard AC voltage.
Just like Europe (etc) runs off 220VAC. And get this, it's 50Hz and not 60Hz. Crazy stuff.
Wow, there's a big world out there ... :rolleyes: ... lots to learn.

LOL brutal dude
 
LOL brutal dude

Just trying to state facts and educate. LOL :001_sbiggrin:

The voltage in Japan is 100 Volt, which is different from North America (120V), Central Europe (230V) and most other regions of the world. Japanese electrical plugs have two, non-polarized pins, as shown. They fit into North American outlets.

ib2225.jpg


http://www.japan-guide.com/e/e2225.html

Here's Japan -> it's somewhere near China. Where ever that is ... China, is that a real place? Crazy. :D And why is there a North and South Korea ... why not just one Korea. Crazy.

japan-map-2016.gif
 
Anyway, back on topic.
That Bob Roberts setup is pretty good for a test bench.
I would say any test bench needs an iso transformer ... either a discrete one or one in a commercial enclosure. As stated, the monitor is floating, so you need to isolated/"disconnect" AC mains from it.

main-qimg-3efc1a4b00a76c5995f306134abe03e0


The BK TR-110 is popular as it provides the isolation and tapped secondaries. Perfect for a test bench. Sometimes found on Ebay. :)

124-268.01_s500_p1._V475e3768_.jpg
 
The benefit of the ISO tap like VectorCollector posted is that if you only need to test the monitor then you can plug it right in to the ISO tap. If you have a TPG this is a pretty portable setup. There are other models out there and you can search eBay for "isotap"

I use a model like this. You still need to use your meter to make sure you get the right A/C output but I find it very useful and flexible.

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I had assumed that I could just put a switch on the Bob Roberts setup to turn off the DC side if I wanted to. I think the ISO tap stuff you're posting is great, but I really only want to focus on Electrohome and Wells monitors right now. If I find myself getting into more elaborate setups, perhaps I'll come back to that.
 
I had assumed that I could just put a switch on the Bob Roberts setup to turn off the DC side if I wanted to. I think the ISO tap stuff you're posting is great, but I really only want to focus on Electrohome and Wells monitors right now. If I find myself getting into more elaborate setups, perhaps I'll come back to that.

Have the switch turn off the D/C power supply by cutting the A/C input. Don't cut out the D/C output.

Running Power supplies for long periods of time with no load is bad for them.
 
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