27" WG2572 Monitor requires Isolation Transformer?

[Lukey13]

Hi people, ok so just looking for a wee bit of technical info and despite searching I cant seem to find my answer...
I recently picked up a 27" Wells Gardner WG2572, 27K5201 monitor and I'm unsure as to whether this monitor requires an isolation transformer to be used or not?...

I have a 25" U5000 and according to the manual the 25" does not require one, but as stated I have on idea if the 27K5201 does.

Do any of you guys know for sure, or better still own one of these monitors to speak from experience?

Many thanks, all help and advice is greatly appreciated as always!

[lilshawn]

i believe you typo'd but the WG2572 is a 25 inch 7200 series monitor so the K7200 (27K7201) is switchmode and does not require isolation.

27K5201 is a part number that doesn't really make sense to me here.

IN A NUTSHELL,


if it has a switchmode power supply for the B+ it will not need an isolation transformer.

if it has a regulated power supply for the B+ it will need an isolation transformer.

regulated units can be ID'd by the use of an (usually) STR regulator chip (like the STR30123) after the AC comes into the chassis and gets converted to DC in the bridge rectifier... to produce one large 130 someodd volt power rail that is whittled down by resistors to feed various parts.

switchmode units can be ID'd by the use of an IC control chip (typically 8 pin CS3842A) and a high frequency MOSFET switching the rectified line voltage DC into a primary transformer to produce many smaller voltages (130v B+, 24v, 12v, 5v, etc depending on what's needed) this is usually done with a fairly large transformer so they usually stand out.

[Lukey13]

Ok so here's a photo of the box, the monitor is 100% a 27"..
These codes are both on the box and the monitor itself:

[grantspain]

its a u5000, works on 90vac to 265vac direct from mains power

[Lukey13]

Thanks guys, I'm really pleased with it as it's brand new still in box and exactly what I was after for my project. I'm just very dubious about how to run it as obviously I do not want to damage it...
I've seen it switched on and working before I bought it but I want to make sure I set it up right in my new cabinet when it arrives...

There is a sticker on it that states 110v but there is no mention of a higher voltage capability on it, is that normal for one of these?
When it was tested it was powered up through a 230-110v step down transformer (here in the Uk) and just displayed the colour/test screen as shown below

[grantspain]

https://www.wellsgardner.com/wp-content/uploads/2016/08/U5000_25.pdf

[Lukey13]

Awesome, I saw that manual online before but completely missed that it was also for the 27" and my part number is in there so yep, pretty much confirms 27" U5000 for me.
Thanks guys!

Although it states no Isolation transformer required, would any of you recommend installing one for added protection to both me and my jamma PCB's themselves?

[lilshawn]

that's the best part about a switch mode supply. you can plug it into just about any voltage and it will adjust it's pulse width switching of the output MOSFET to match the output it's expecting. so on 100v...it will be more "on" than "off" whereas at 240v, it would be more "off" than "on" not needing as much to get the same output.