In article ,
Skipweasel writes:
In article ,
says...
As a child, when non-rechargable batteries were all zinc-carbon,
I discovered you could get a bit more use out of them if you
warmed them up in the oven.


I found you could exract the carbon rods and use them with a car battery
to make nice hot arcs.

I did that with a school friend. IIRC, it was triggered by an article
in Scientific American. It didn't use car batteries. I can't recall
what the article specified, but we worked up to using mains, and my
mum's 2.4kW electric kettle as a ballast. Probably should have been
using darkened/UV goggles or welding hood too, but didn't know that
then. I think we used sun glasses, and you couldn't look at the arc
anyway - it was far too bright.

My 2nd year university project required a carbon arc lamp (to use
the electrode as a 4000K black body emitter). The lab had a 220VDC
mains supply for such things, and it ran from that (I presume through
a resistor ballast, but I can't recall that now). It had proper
carbon arc rods though.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]