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Protecting Small Transformers
Hi All!
I am new to the list and as this is my first post i will tell you a little
about myself, I am 15 and live in cambridge (england), with the help of Bob
Golding i recently built my first coil, it runs on a pair of OBIT's and will
produce 1' streamers using a fan cooled 5 stage gap and a MMC 3" secondary on
pvc pipe
Unfortunately i am suffering a rather high transformer kill count (three so
far) (yes bob, the other one blew :-( last night, but not before i got 1'
streamers out of it :-) )
i did a post mortem on all the transformers and it is the seconaries that are
blowing, their resistance halves which suggests to me that they are either
melting in the middle (unlikely) or being killed by some sort of high frequency
resonance in the pri circuit because rf tends to get thing in the middle (am i
right?). I have just built the new spark gap which will quench better than the
previous primitave design with two bolts and so produce more RF in the primary
tank. I know the gaps are not too wide 'cos i set them by connecting a
transformer over them. i tried a safety gap standard two lives and an earth
design.. which promptly led to a fatality and i removed the gap - it was
hissing (corona) and draining tons of power from the circuit. i need some kind
of filter network, but what exactly am i filtering and how should i go about
doing it.
2ndly since i am using two transformers in paralell is there some way of making
sure the load is spread evenly (only one blows at a time) or should i just give
up and start looking (harder) for a NST?!
Thanks very much
Alex