From: Thoremail@example.com (P!erCer)
Subject: Re: Ultracapacitors and little racing cars
Date: 31 Dec 2002 16:10:43 -0800
NNTP-Posting-Date: 1 Jan 2003 00:10:44 GMT
This makes me less sure my device is a capacitor...
It is yellow. It has a contact at either end. No labels, no
It charges through about a 4K ohm resistance attached to two standard
AA cells in series, and takes 45 seconds for the LED indicator to go
out that indicates charge is complete. I assumed the indicator was
sensing current flow through the wire, but am no longer sure.
Upon testing, the voltage varies as current is drained from it, but
doesn't seem to charge beyond 1.8 volts.
When shorted, voltage difference between contacts drops to zero (duh)
but as soon as short is removed, the difference goes back up again.
The same thing is true with current flow through my DMM, with a slight
current almost impossible to get rid of (fraction of a milliamp).
Ok, damn. I just tested again after three days, and a voltage
difference is still there. That probably rules out a
capacitor...unless it has very low leakage...but if this is a battery,
it is weird.
Oh well, an ultracapacitor would have been cool. At least I learned
something soin all the searches and stuff about it. :P
Any tests to completely confirm what this yellow barrel is?
Andrew Kohlsmith wrote in message news:<2842326.FmGRfm0KLi@mixdown.org>...
> > I got one of those really small remote control cars for Christmas.
> > It's about the size of a matchbox car, and runs off a tiny
> > ulracapacitor in the body. The circuit board is exceedingly small,
> My son and I both got ZipZaps for Christmas -- I took mine apart too, but
> the documentation says it's a NiMH battery, not an ultrapacitor. I thought
> that was strange, as a 45s charge on any battery isn't much, especially
> coming from a pair of AAAs in the control unit.
> There are some neat mod pages online (I just did a google search for zipzap
> modification or hack or something like that).