One nit-pick: measure the actual AC line voltage and use it where Joe has "115v". Locally it's 118-123v, depending on the local load (i.e. lower on a summer day, highest during a winter night).
And sometime when you have a free hour, wander around the house and count how many wall warts you have in use, and feel each one and see just how warm it is. Then if you want to see an interesting number, unplug each one, and take it and it's load and plug it into a power strip, or some strips that are daisy chained... I did this at a friend house and we ended up with about 20 plugged into a half-dozen power strips and totalling about 2 and a half amps of AC... He's got 112-114v of AC at his house so using 113 we get 255.2w ... divide by 1000 and times 8760=2235.5, or 2.2kw just in wall wart wastage. Think how many houses have that exact same situation. Might be worth putting a switch on an idle wall wart.... Or plugging the modem, inkjet printer and USB hub wallwarts into a power strip, and using the strip's switch to power down the entire computer system when it's not in actual use. Mike WA6ILQ At 11:24 AM 7/19/05, you wrote: >The easiest way to tell would be to measure the AC >current draw in idle. Then measure the DC current draw >in idle. > >You can get a pretty close watt figure by multiplying >the amps times the voltage (115v) on the input side, >and doing the same thing on the DC side. The >difference between the two is your wasted heat. If you >convert the watts to kilowatts (divide by 1000), then >multiply your results by 8760, that will tell you the >number of wasted KWH in one year. > >Example: .72 amps draw at 115 volts, 1.3 amps draw at >13.5 volts. .72 x 115 = 83 watts in. 1.3 x 13.5 = >17.5 watts delivered. This means 65.5 watts are >wasted, or about 574 KWh/year. > >Joe > > >--- Dexter McIntyre W4DEX <[EMAIL PROTECTED]> wrote: > > > Anyone have an idea how much power would be saved by > > running a MSF-5000 > > that is idle most of the time from a switcher > > instead of the stock heavy > > iron power supply?. The transformers produce a lot > > of heat just in > > standby mode. I have several of these machines on > > line and also a GE > > repeater with a big transformer. > > > > Dex, > > W4DEX > > > > > > >____________________________________________________ >Start your day with Yahoo! - make it your home page >http://www.yahoo.com/r/hs > > > > > > >Yahoo! Groups Links > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
