Re: (ET) Battery maintainers

[Jim Coate <jbc coate org>]

One catch is that the 36 volts from the ET batteries is DC (direct 
current). The 120 volts from the outlet in your house is AC (alternating 
current). A cheap transformer (wire wrapped around a chunk of iron) can 
change AC voltages at almost any current level and the resulting AC can 
easily be changed into DC with a diode (also cheap); changing DC 
voltages requires a bunch of electronics that basically converts the DC 
to AC, changes the voltage, and then back to DC again. Due to the extra 
parts & complications, and the high current levels and small market 
Chris mentioned, the DC-DC convertors cost a bunch more. Especially a 
DC-DC convertor that operates with a wide input of say 25-50 volts that 
the "36 volt" pack may actually be at at various times.



Fixinguys aol com wrote:
> Question from a non-electronics guy:
> My wife has a wall cube gizmo which takes 110v and distributes it to 
> either 18v, 12v, 9v, or 6v, depending on the port you plug into the 
> laptop, radio, etc.  Why does it seem so elusive to develop a unit which 
> takes 36v and distributes it to 18v (lift), 12v (lift), 24v (chainsaw), 
> or 36v (original implements), thereby eliminating equalization problems 
> and extending battery life?
> SteveA
> e15

_________
Jim Coate
1970's Elec-Trak
1992 Chevy S-10 BEV
1997 Chevy S-10 NGV
http://www.eeevee.com