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Re: Scopes Away!



Hi all,
        I've just received some of the photos I took of the o'scope 
traces for this series of experiments and they all came out although 
a couple of the traces were a bit dim. Most are clearly visible 
however. I'll forward a few plus one of the test setup to Jim for 
scanning onto his ftp site.
     In connection (npi), I was wondering at the time why the primary
Q was a lot lower than expected. The substrate diode in the MOSFETs
is almost certainly the culprit. I could see rectified low f rings 
associated with the charging choke (minus diode) and primary cap
when using very slow break rates. Given that little problem, I think 
the expt was quite successful and the traces were not too far removed
from what you would normally see with the real gap in place. Some
envelope distortion is evident in some of the tests.

    Question - is there an easy way of destroying the diode without
ruining the MOSFET? (Alan, anybody?). Alternatively, are there any 
devices without this built-in nuisance available (type/s please)?

Regards,
Malcolm