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Homebrewed Electricity => Controls => Topic started by: juiced on November 03, 2004, 04:43:39 PM

Title: AC/DC Inverter Losses?
Post by: juiced on November 03, 2004, 04:43:39 PM
Somebody asked me how much loss a AC/DC inverter would experiance. I think it depends on the size and design, and think there must be either a statistic or formula to use on specific inverters.
Title: Re: AC/DC Inverter Losses?
Post by: baggo on November 04, 2004, 09:28:14 AM
Hi Juiced,


I did some efficiency tests on some cheap MSW inverters about a month ago after someone ( Bob Golding I think ) raised a question about this very thing. I posted the results for a 150W in one of my diaries. I also tested a 300W and a 600W and was quite surprised at the results which were better than expected.


For the 150W - efficiency was over 85% between 30W and 55W, and 90%+ between 55W and 150W with a maximum of 92%


For the 300W - 85%+ between 45W and 75W, 90%+ between 75W and 200W, falling off after 200W, maximum of 93% at 150W


For the 600W - 85%+ between 55W and 90W, 90%+ between 90W and 300W, falling again after 300W with a maximum of about 92%.


At low outputs the efficiency is not that good because the power taken by the inverter circuitry becomes a significant percentage of the power taken by the load. At high outputs the losses in the inverter become significant again. This shows the importance of matching the inverter size to the load i.e. don't use a 2kW inverter to power a 50W load as the efficiency will be poor!


Hope this helps,


John

Title: Re: AC/DC Inverter Losses?
Post by: juiced on November 04, 2004, 03:54:33 PM
Wow man, i couldnt have asked for any better! Thanks alot.
Title: Re: AC/DC Inverter Losses?
Post by: ghurd on November 06, 2004, 11:45:35 PM
John covered it.


But some will waste a lot more than others.