On 11-29-97 Ian Woofenden wrote to Day Brown... 
 
 IW> On (20 Nov 97) Day Brown wrote to Roy J. Tellason... 
 IW>  
 IW>  DB> Lemmee know whatcha find Roy.  I had a brand new BJ cannon 
 IW>  DB> that immediately *fried* when run on a sin wave inverter.
 IW>  
 IW> On sine wave, or modified sine? What brand of inverter? 
Tripplite 400 watter. dont remember the model number, it was 
only a year old at the time, but my house burned down a month 
after that, so i never got to dig into the cause of the problem 
very far.   
 
However, based on my understanding of SMPS and inverters, and the 
PWM chips used in both, it looks like a harmonic interaction when 
one of the PWM chips happens to make a sample that co-incides with 
the noise spike on the AC curve from an IGBT controlling current 
on one of the multi-tapped windings that are used by both designs. 
 
If I *had* to run a computer on an inverter, I'd use an isolation 
transformer, and hope the hysteresis would damp the ripple in the 
sin wave from the inverter, and pick up the slack when the SWPS 
IGBT shuts on/off.  Of course, isolation xfmrs are big, expensive, 
and heavy. 
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 * OFFLINE 1.58 * So much car trouble in life, they hadda jump start his 
hearse. 
--- Maximus 3.01
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