Hi there cypher,
I havent been able to find anything either.
I have a little information based on some quick tests...
The charger i have is sync'ed to the 60Hz line.
It puts out pulses of current one for every zero
crossing. The device may measure peak voltage across
the cell, turning it off each time it reaches something
like maybe 1.65 volts (this level not verified exactly).
The next zero crossing triggers another pulse, so
there are 120 pulses per second with a 60Hz line
until the cell gets near full charge.
After some time the cell gets charged up somewhat, and
the time it takes to reach the approx 1.65 volts gets
shorter and shorter, meaning the pulses get narrower
as the cell charges. Eventually the pulses start to
skip (dont occur for every single zero cross anymore)
until there are very few pulses per second.
There's no way to verify that the measurement of the
terminal voltage is the key to determining pulse length,
except to try charging a cell using this method and
see what happens, unless of course you can get your
hands on some data about these chargers...would
be interesting to see.
Take care,
Al
