iPad power supply

[tedstruk]

I found warts for these, online that deliver 12w for the iPad. I did some math
where 1 amp is there and 12 watts are there and there is 12 resistance there.
w / i = v
v squared / 1 i = r

144/12=12r
12w/1i=12e

is the 12r arbitrary? no I think not! so

144/12=12w
(1*1)12=12w
12x1=12w

so 1(2)amp,12r,at 12v should charge the iPad,,, someone left the adapter at home...needs to charge from 2% battery,,, Why won't it charge through my Pc's USB port?

 

[davenn]

where 1 amp is there and 12 watts

only if there is 12V

I have no idea what these resistors are that you are referring to ??

 

[tedstruk]

no resistors as of yet, I want to slap a cheap one that works togther for emergency use...
I have no specs so I didn't know where to start, I only have the 12w spec from ebay.

 

[tedstruk]

ipad at 2%, The PC usb port did 52% overnight

 

[tedstruk]

I learned that the conditions nessesary to charge a battery was .oo2 amps. The ones in my radios are 18.85mah. Thats .002 close .01885 the radios use. But I was listening to some guys at a shop and they were talking watts.
I thought watts were how much power something was capable of handling. Anyway when I told them what I knew, they said it was all numbers and ignored me.

This is really the first chance I have had to research the watt thing.

I think the numbers in the equasion that I am looking for are similar... .002w .002a .002v .002r?
when all thats right, the battery takes a charge... and it takes quite a while to charge it!
NOw capacity, thats what watts is all about right? and a fancy LIon battery is designed for fast charge, probably around 4 or 5millis. so I do more math.

 

[Bluejets]

I think you would need to do some study on the subject as it is clear you have no idea and are jumping to conclusions. ( your own) which are not correct. Plenty of tutorials online.