Kill-A-Watt Killing

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>

Hi All,

Last Sunday I blew my Kill-A-Watt meter playing with my coil.  I am not 
sure when it went (too dark).  Grounding was poor and we were sticking it 
all around the systems AC wiring.  We were bypassing filters and such 
trying to track down what turned out to be a MOV problem.

It was pretty messed up.  Drifting, big currents with nothing connected, 
voltage and frequency readings randomly off.  Nothing inside was obviously 
burnt up.  It appeared that the basic logic worked, it was just that the 
input metering was bad.

I replaced the LM2902 with a LM324 (fast Radio Shack replacement).  That 
fixed a lot of the trouble.  The drift and offsets are gone now and the 
frequency reads right again.  The only problem now is that the voltage 
reads 60% high and the current is 23% low.  I think the LM324 is "close 
enough" to the LM2902 so that should not be the problem (but it is only 
running on 5V in this design)?  I had already ordered parts from Digikey 
before I knew I needed some more LM2902's...

I am going to try desoldering and carefully testing the input parts 
next.  Maybe a bad part in there I am not seeing.  Hopefully I can get it 
going again since the problems don't seem unfixable.   I did order up two 
new meters just in case ;-))

So I guess even the latest ones can be damaged by Tesla coils.  But this 
kind of damage my be eliminated if I can find out "why" and add a few extra 
protection components.  Stay tuned...

Cheers,

	Terry