re: current draw
 

I want to run my g4 and cinema screen through a 12v to 240 volt full sine wave inverter, as we are on solar power. We are 240 volt in Aussie and the screen draws 1.75a and the comp 4.5a as written on the data plates.
This is about 6+amps meaning say 7 to be on the safe side and that is 1680 watts. It seems a lot: are my calculations correct? Do they really draw that much?
I didn't know which forum to put this on.

Rick Banfield

No one replied to this and as I'm Aussie too i thought i would try.
Yes I believe they draw a lot of power, they are nice and bright, but not as much as a conventional monitor that produces a lot of heat too.

My brother has a farm and is total solar power too. He uses a laptop PC thingy, they are not very bright and you have to be looking directly front on square to see the screen properly. Maybew you should get a PowerBook next time you upgrade. 17" G5 gotta be here next year?

cheers

Power draw of PCs and monitors
 

I may be relatively new at DV and Premiere but I can speak to
power draw. I have a 3.3KW peak rooftop solar array on a "grid tied" system so that meets about half my year-round energy draw, Air Conditioning included here in Los Angeles.

I purchased a little box called "Kill-a-watt" that can show instaneous current draw or integrate over a period. You would think our gear would glow dull orange if they drew, on average, what the power draw plate on the back says!

I have a dual processor Pentium 3, 850 MHZ with 3 scsi drives, IDE DVDRW and CDRW, film and flatbed scanners and a flat panel screen. Newer machines actually draw less. It starts up with everything running, including display, at 204 watts and quickly falls back. While running Pinnacle DV500 capture it draws 167 watts. I have the drives go to sleep after 20 minutes. This is partly because the drive I use for capture has a noticable hum. After all drives are idle, the setup draws only 115 watts. The flat panel only draws about 30 watts of that. The average CRT monitor or 19" TV draws about 90. My Sony XBR 50" LCD projector TV draws 120. Thats a 100 watt mini arc light and 20 watts for every thing else. By the way most plasma sets run quite hot and draw 380 to 500 watts. Separately, a Toshiba Cable Modem, SonicWall firewall and cheapo 10/100 8 port hub only draw 35 watts total.

Add on: You have to figure your inverter is probably only about 80% efficient. So 240 watts divided by 12 volts would be about 20 amps but grossed up by .8 would be 25 amps at 12V.

Rick, you are right on target. The G4 is rated at 4.5 amps at 240 volts (8 amps at 120v), or 1080 watts. Plus the monitor.

So, since Watts= Volts x Amps, your result is mathematically correct.

But I am sure that these are maximum peak current ratings, not steady-state.

Now, Don you have got my curiosity going, I'll have to clamp an ammeter on this thing. Or maybe get a Kill-A-Watt, they're only about $35...too bad they don't make them in Rick's voltage.

Re Kill-A-Watt and 220v
 

The one of its 4 measures is voltage, so despite the "wrong" plug, it may actually work just fine anyway. I suppose you could contact them.

Don

Actually, I ordered one after my last post, so maybe I'll just see if the instruction manual addresses this question.

cheers
m

OK, now that I am the proud owner of a Kill-A-Watt, I can tell you that the instructions specifically state max voltage to be 125. But anyway, I ran the test on my G4 tower and 22" tube, and found the maximum draw to be no more than 2.28 amps at any time, including monitor startup surge. Normal steady-state current was around 1.86 amps. This was at a measured 119 volts. So, to work it out to Aussie standards, cut this figure in half. We're talking 223 to 274 watts. About an amp at 240 volts.