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From: spcecdt@ucscb.UCSC.EDU (Space Cadet)
Newsgroups: sci.electronics
Subject: Re: How Do I Build "Electric Shocker"
Message-ID: <2763@saturn.ucsc.edu>
Date: 11 Apr 88 07:55:09 GMT
References: <8287@oberon.USC.EDU>
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Reply-To: spcecdt@ucscb.UCSC.EDU (Space Cadet)
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     A transformer will only work with a changing current.  The circuit you
are refering to probably simply connected a battery to the primary of a step-up
transformer; the changing current at the moment the primary circuit is closed
and at the moment it is opened will produce high-voltage spikes at the
secondary.  The last shocker I made used a simple 555 astable to direct-drive
the input of a small audio tranformer (use one that is listed as having a large
ratio of input to output impedance).  DISCLAIMER:  BE CAREFUL.  A device that
barely tingles when pressed against dry skin can deliver quite a jolt when
touched to wet skin (as my friend found out the hard way... :)
     As for other "joke" circuits... my favorite is still "the drip".  I saw
the idea in a ca. 1970 electronics magazine and implemented a modern version.
It is a small (hidable) device that emits a periodic chirp.  It can drive you
up the wall just as effectively as a dripping water faucet.  
     The last one I built used a PUJT timer set to produce a pulse every five
minutes.  I put a piezo beeper (muRata PKB8-4A0) between the cathode and ground
so that when it triggered the current from the cap would be dumped through the
beeper; it was very efficient since the same current was used for timing and
beeping.  In fact the average current was about 2.7 uA, so it would last at
least half a year on a 9v battery...
--
> Hello, lift.   # We're going to space if we have to walk. -Jerry Pournelle  <
< -Marvin the PA # The meek will inherit the earth.  WE will go to the stars! >
> John H. DuBois III # spcecdt@ucscb.ucsc.EDU  ...!ucbvax!ucscc!ucscb!spcecdt <