zapping NiCAD Cells
rhill at siue.edu
Sun Jul 20 14:49:48 MDT 2014
Interesting; I hadn't heard of doing that before. This avoids having
to convert to DC! I guess the resulting magnetization depends on
which peak of the AC blows the fuse wire, whcih would depend on things
like when and how fast you plug it in: On a time scale of the period
of the waveform, the plug-in connection might be established
relatively slowly, so it might take several cycles for the current
wveforem to build up to where it blows the fuse wire.
------------ On Richard S's message ------------
> You reminded me of the old procedure for magnetizing an iron bar.
> Wrap it with heavy insulated wire, and wire it in series with a much
> finer wire that acts as a fuze. Then plug it in. Current rises
> as rapidly as the AC power waveform and the inductance will allow
> until the fine fuze wire blows. The current gets very high, more
> than enough saturate the iron bar beyond its magnetic capabilities.
> The fuze wire must be fine enough to blow in a small fraction of one
> cycle of the 60 Hz AC power.
> I tried this method when I was about 15. My dad smelled the burned
> wire and came running in. When he saw what I had done, he was
> really angry. But the house circuit breaker did not blow. I guess
> my fine fuze wire was fine enough.
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