Path: utzoo!attcan!uunet!husc6!bloom-beacon!tut.cis.ohio-state.edu!rutgers!njin!princeton!phoenix!pucc!WINNIE
From: WINNIE@pucc.Princeton.EDU (Jon Edelson)
Newsgroups: sci.electronics
Subject: Re: 9-volt / rocket launcher?
Message-ID: <6767@pucc.Princeton.EDU>
Date: 28 Dec 88 00:20:24 GMT
References: <2557@ddsw1.MCS.COM>
Reply-To: WINNIE@pucc.Princeton.EDU
Organization: Princeton University, NJ
Lines: 29
Disclaimer: Author bears full responsibility for contents of this article

In article <2557@ddsw1.MCS.COM>, benfeen@ddsw1.MCS.COM (Ben Feen) writes:
>
>How can I use a 9-volt battery and other componentsx
>  to heat something up enough that I can light a fuse with it?
> I want something which will get hot without shorting out the 9-volt.
>Will diodes work, or am I mistaken?
 
Any component will get hot if you pump enough current through it, and
diodes will allow that :-)
Actually, you want something that is high in resistance in a small
place.  These are sold by Estes as model rocket igniters.
 
Something that you can do is take a piece of wire and bend it at a
sharp angle, then cut throught most of the wire at the bend so that
you end up with two thick wires joined by a very thin bridge.  If
you run current through it, the bridge will get hot.  I have done
this with copper wire- nicrome might be better.  Although you are
"shorting" the battery, the cross section of the thin part is very
small, so it isn't much of a short.  Also, the wire melts away
rapidly, so the current drain does not last long.
                                       -Jonathan Edelson
winnie@pubear.princeton.edu
      @pucc.bitnet
      @pucc.princeton.edu
      @phoenix.princeton.edu
" Where am I going?  I don't quite know.
  Down to the stream where the king-cups grow-
  Up on the hill where the pine-trees blow-       When We Were Very Young
  Anywhere, anywhere.  *I* don't know. "              by   A. A. Milne