Path: utzoo!censor!geac!torsqnt!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!spock!petersd
From: petersd@spock (Dana Peters)
Newsgroups: sci.electronics
Subject: Re: Zap, fry, and sizzle
Message-ID: <2353@petersd>
Date: 2 Mar 90 14:46:52 GMT
References: <799@gold.GVG.TEK.COM>
Reply-To: petersd@petersd (Dana Peters)
Organization: Mitel. Kanata (Ontario). Canada.
Lines: 51

Passing this message on for a friend (Glenn Robb)-

Re: Things that go BANG

Varistors:  There are two advanced techniques -

1) Celestial Simulation
This recipe is for devices rated with a clamping voltage below
400 V.   Source voltage: 600 V, Source impedence: as low as
possible, preferably less than 15 ohms.  Apply high voltage leads 
to leads on varistor, stand back, protect face, apply voltage.
Yield is equivalent to only a 2 inch fire cracker, however, 
pyrotechnical display rivals the best Fourth of July tantalum 
capacitors.

2) Crash and Burn
The trick here is to over-watt them s l o w l y  by applying a
voltage just on the "knee".  This is best performed with a power 
supply that approximates a constant current source.  A 2.2 Ampere
setting is usually about right. Creates lots of pitch black fibrous
smoke and plenty of toxic gases.  Sort of a mini tire fire.

_______

There is a wealth of information available to those wishing to
perfect their destructive techniques.  In fact, a great number of
techniques are published as American National Standards.  My
personal favorites are from Underwriters' Laboratories Inc. and 
here are a few references:

Standard for Safety Number 1459 Issue 2 "Telephone Equipment",
Sections 50 and in particular 50A. What's really great about this 
standard is that the tests are supposed to represent real world 
events. This standard is the source for the varistor recipe 
above.  I bet you never realized how dangerous your phone could be!

Standard for Safety Number 746C "Polymeric Materials - Use In 
Electrical Equipment Evaluations".  To make best use of this 
standard, you will be required to obtain the companion standards;
UL 746A&B and UL94. UL 746C contains such goodies as the 5 inch flame 
test (section 26) and includes a schematic for the simply 
wonderfull "Surge Generator Circuit" (figure 52.2) which is used 
for the 6KV Voltage Transient Test (par. 52.6).  

Warning:  These standards are not to be used by the weak-hearted,
          or the casual enthusiast, and are intended for the 
          professional engaged in serious study / investigation.

--
Glenn Robb
uunet!mitel!spock!robbg