Regacy

Dull I know but I believe when you power on a monitor the power draw is significant.
The question is, how long do you need to leave a monitor on stand-by for it to have been worth turning it off and on again?
Ten minutes, half an hour, a couple of hours, over night?
Anyone clever out there know the answer?

Brendan Hughes

Good luck.

http://bbs.scoobynet.co.uk/showthread.php?t=338109

ALi-B

iTrader: (1)

Easy to find out if you have an ammeter

AndyC_772

iTrader: (2)

The actual energy used at start-up is minimal - although the surge is large it's very short duration and not worth worrying about. Your concern should be premature failure due to heat cycling (eg. thermal expansion and contraction as it warms up and cools down), and stressing of the power supply components especially the electrolytic capacitors.

On the other hand, the phosphors age with use rather than time, so they'll last longer if the monitor is turned off when it's not in use.

So, turning your monitor off frequently will always save electricity, but it might shorten the lifetime of your monitor - depending on what you think its ultimate failure mode might be.

I generally set mine to switch off after about 10 minutes of inactivity.

AndyC_772

iTrader: (2)

Not true, I'm afraid. As well as being exceptionally dangerous (putting it in series with the mains inlet to the monitor), it won't actually tell you anything at all. The highest current range on most handheld meters is 20A, which is much less than the current peak that the monitor will draw. It also won't sample fast enough to capture the maximum of the peak, nor will it tell you the duration or shape of the peak.

Furthermore, the real power drawn isn't just 230*A because you don't know at what point during the 50Hz cycle the monitor is switched on, and you also aren't taking into account the effect of the power factor of the monitor's PSU.

Inrush current measurement requires expensive and specialist equipment I'm afraid - ask any EMC lab for more details.

ALi-B

iTrader: (1)

Perhaps I should meantion the use of an inductive clamp, a storage scope and RMS measurement then

AndyC_772

iTrader: (2)

_Meridian_

iTrader: (1)

Actually the biggest problem is that you'll probably break the power switch if you keep using it - they usually go wrong long before anything else.


M