Hi to all,
i made a diy output transformer-but there is something wrong with the design.
Please take a look at :
http://www.8ung.at/triode/
for explanation and photo.
Thank you very much,
frank
i made a diy output transformer-but there is something wrong with the design.
Please take a look at :
http://www.8ung.at/triode/
for explanation and photo.
Thank you very much,
frank
I'm not a transformer guru but to me the graphs seem to indicate that you have a lot of leakage inductance forming a resonance around 50 kHz with the stray capacitances.
Did you measure them with proper loads at both primary and secondary?
Leakage inductance can be caused by partly the relatively few interleavings and partly the low fill. Other factors could be the way you wound the two primary partitions. Did you start the two from the same end of the former or reversed?
I would try with more interleaving and use heavier wire for the secondaries instead of 3 thin trifilar. As a ballpark, 4 primary partitions in series (2 starting from one side of the former, 2 from the other) and 5 1.0mm wires secondaries. This should increase the coupling and thus reduce the leakage inductance. Try to fill the former as much as possible. (winding multifilar isn't bad though, just expensive. It's used in switching transformers for SMPS)
Your transformer looks nice, would be a shame if it didn't work.
I talked with transformer gurus many years ago, they all say you have to scrap the first 10 or so transformers before you get a grip over the magic of winding.
Just me 2 cents.
Edit: I forgot one thing, when measuring load the primary with the intended DC current.
Did you measure them with proper loads at both primary and secondary?
Leakage inductance can be caused by partly the relatively few interleavings and partly the low fill. Other factors could be the way you wound the two primary partitions. Did you start the two from the same end of the former or reversed?
I would try with more interleaving and use heavier wire for the secondaries instead of 3 thin trifilar. As a ballpark, 4 primary partitions in series (2 starting from one side of the former, 2 from the other) and 5 1.0mm wires secondaries. This should increase the coupling and thus reduce the leakage inductance. Try to fill the former as much as possible. (winding multifilar isn't bad though, just expensive. It's used in switching transformers for SMPS)
Your transformer looks nice, would be a shame if it didn't work.
I talked with transformer gurus many years ago, they all say you have to scrap the first 10 or so transformers before you get a grip over the magic of winding.
Just me 2 cents.
Edit: I forgot one thing, when measuring load the primary with the intended DC current.
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