Square wave & Screens

[HavocXphere]

Just got my Samsung screen back from repairs (within warranty period @2.5y ftw). Inverter board was busted.

I'm wondering whether this could be cause by running it off a cheap UPS? Or is it the constant going to sleep & switching back on (I've increased the time to sleep the screen now).

I'm not even sure whether the UPS is outputting square wave (line-interactive UPS), but I suspect it does.

The alternative is to run it directly off the mains, but I think thats riskier on balance.

General thoughts on the matter?

 

[Pada]

The line-interactive UPS would only alter the sine wave to a square one when running from batteries.

I'd say that you're better off running it from a cheap UPS than directly on the mains, since the cheap UPS' often provide some form of surge protection.

I'm really not sure what would've been the cause here. What Samsung model was it?

 

[HavocXphere]

I'm really not sure what would've been the cause here. What Samsung model was it?

2053bw. Gift someone bought at IC for me. Was actually surprisingly painless getting it fixed.

Thanks for the info on the UPS.

EDIT: Background thread here http://mybroadband.co.za/vb/showthread.php/298491-GFX-Signal-mystery?highlight=

 

[Gnome]

Which UPS, make, model, etc?

Some UPS have what I call overzealous trim. Meaning the voltage increase to around 240volt (which it VERY commonly does in SA) and then the UPS steps it down. That would definitely put some strain on the screen's PSU. Btw. trim happens even if you are running on AC.

And yes, if you run off batteries quite commonly the square wave could be the problem. Square wave isn't suitable for many types of PCFs (power factor correction). If the PC and screen makes a loud buzzing noise, that would be the PCF. The buzz is caused by the components actually vibrating at the stepped wave frequency. Naturally it isn't good for it

Only "cheap" UPS I know of that outputs sine wave and doesn't trim over-zealously is the APC Smart UPS Range (not the Smart UPS SC range, they are square wave). I own one, and you can set the input voltage (230v for SA) then it only trims once the voltage reaches 253v (trim down) or 208v (trim up). I own both APC and Powercom. Powercom just doesn't compare to APC Smart UPS, but then again, they aren't cheap. Powercom Black Knight trims over-zealously but the units they sell locally are 220v units which explains why it does that (at 240v it steps down to around 208 volt).

Here in Pta, where I live, the UPS log shows that the lowest voltage recorded was: 230.4VAC (That is apart from 0volts ) and highest was: 241.4.

 

[Pada]

Thanks Gnome. I completely forgot about the trim and step-up that the UPS's do

 

[Gnome]

Thanks Gnome. I completely forgot about the trim and step-up that the UPS's do

Hehe, well the trim wouldn't be a problem if the local people didn't sell 220v models. Someone should send them the memo that we use 230v locally

 

[Pada]

Hehe, well the trim wouldn't be a problem if the local people didn't sell 220v models. Someone should send them the memo that we use 230v locally

Yup. That is just one of the many reasons why I bought the expensive APC Smart-UPS 1000VA USB & Serial 230V.

Perhaps the people just can't calculate 400 / sqrt(3) accurately?

 

[Gnome]

Nice UPS, I got the 1500VA model (SUA1500i), which I realized was overkill so basically running every PC in the house from it now I just wish that APC PowerChute software had more options (the shutdown options are a bit restrictive). Does the 1000VA model also have a fan?

 

[Pada]

Nope. The 1000VA model doesn't have a fan as far as I can see/hear.

Rory (from Wootware) said that the UPS makes an incredible noise when you charge the batteries for the first time, but mine was charged to begin with so it was quiet right from the moment I plugged it in.

 

[HavocXphere]

Nice info Gnome. Thx

Which UPS, make, model, etc?

Blazer 600VA, which apparently has 230V output. Specs here.

Prior attempts to link it w/ PC failed, so I don't really know what it is doing.

The UPS does make a constant buzzing sound (like some power bricks do). On the other hand it makes a beeping sound if there is a brownout/blackout so maybe the buzz is normal.

I can probably get access to some high grade electricians gear do you reckon I could measure UPS output voltage and compare it to mains & work out whether its trimming that way?

 

[Gnome]

Nice info Gnome. Thx

np

Prior attempts to link it w/ PC failed, so I don't really know what it is doing.

:erm: bad sign already...

The UPS does make a constant buzzing sound (like some power bricks do).

My APC & Powercom UPSs don't make any noises, unless they go onto battery mode. The APC makes very little noise on battery mode (slight buss but it is almost drowned out by the fan on the UPS which makes less noise than a normal Intel CPU cooler fan). Powercom makes a bit more noise. But on AC mode they make 0 noise that I can hear. If I put my ear on the case I can hear a slight noise that is sorta like a buzz but so soft that I wouldn't call it that.

On the other hand it makes a beeping sound if there is a brownout/blackout so maybe the buzz is normal.

Not sure about that, sounds dodge

I can probably get access to some high grade electricians gear do you reckon I could measure UPS output voltage and compare it to mains & work out whether its trimming that way?

Hmm, voltage is not really that useful unless it is abnormally high or low. What should be analyzed is the sine wave, you'd need a oscilloscope. But unless you know how to operate it, it would be useless to try. You'd need to know what to look for and how to set the adjustments on the scope to get the correct info.

The frequency, the voltage and the sine wave form (hopefully it is a sine wave) are the most important. All of them are important but I'd say the wave form is the most important factor. If it isn't on battery and you already have a mutilated wave, well that is a serious problem. On battery it would have probably have a square wave. Forget stepped wave (stepped wave is different from just a normal square wave).


If you really adamant about a UPS, get one of the cheap SUA APC Smart UPSs. Yes they are all expensive but they literally last forever. They just shine quality...

 

[Pada]

I could've sworn that I saw the APC SUA1000i at PC-Direct.co.za for R2300 a few weeks ago and now it's R3250 again!
Then again, I was really surprised at the R2300 listing price, since I paid R3200 for mine at that time.

The SUA750i goes for around R2300, which is still very expensive if you have to compare it with like a Proline 650VA UPS which retails for R500. The Proline just gave me a false sense of security, since it usually wasn't able to switch fast enough to backup power.
In the end: you get what you pay for.

At least with the APC UPS' its actually worth it to replace the batteries every 2-3 years, since they'll keep on working just as hard as when you bought them.

 

[HavocXphere]

I'll have another shot at communicating w/ the ups tomorrow...I think the problem might be PC side (stupid serial port tech ftl).

hmm oscilloscope. Dunno about that but I'll see if I can get one, if only for fun.

Replacing it isn't an option atm. Hell the gear connected is probably worth <5k, so no point in buying a 3k ups for it.

@Pada: What do I need drivers-wise for the serial port? I've got Win7 x64 & a Asus P5K mobo without any drivers installed aside from what windows & ATI provided. Would serial port stuff be part of the chipset driver package from Asus? If I plug an old school serial port mouse into it & it works then its fine right?

Already downloaded the software I need (Winpower).

 

[Pada]

HovocXphere: you just need to enable the serial port in the BIOS and then Windows 7 should contain the necessary drivers. All you need to do then is to install Winpower and use the serial cable that came with the UPS.
It is very important that you use the supplied serial cable and not just a generic one!

I still have to get the PowerChute APC software working on Win7 x64, seeing that the one that came with the UPS on a CD didn't want to install in x64.
Windows 7 and HWMonitor is pickup up the UPS, but HWMonitor sux at displaying the info of it.

 

[HavocXphere]

It is very important that you use the supplied serial cable and not just a generic one!

Cable & software - get this - is sold separately. So I've only got a generic one.

So your saying its likely that they swotted pins or some BS like that to make it proprietary?

Also remember why I was so frustrated last time...the pins on the mobo have no indication of which way round the serial connector must go.

Right now I'm trying to organize a serial port mouse so that I know the PC/driver side is OK & sort out the direction.

Thanks for the help pada.

 

[Pada]

Wow that sux!

I got the software license (no CD/installation) and serial cable with my cheap R600 Proline 650VA UPS.
You can try your luck with a generic serial cable, but the odds are pretty slim that it will work.

I feel your pain w.r.t. serial connector, because I blew a mouse & 4GB USB flashdrive last week when I plugged in my front USB connector in the front Firewire socket on the motherboard!