DIYbanter - View Single Post - online Chinese flyback with driver assemblies questions

Ralph Mowery

In article , says...
I'm a big user of eBay and AliExpress, and purchase lots of
high-current and high-voltage stuff, to supplement my pile
of unusual parts, but I'd not come across the items you found.

You have to be careful of the ebay China parts. Seems that many of the
high power and some other parts are not up to what they are suppose to
be.

I have bought some things from China via ebay. Most have been good.

I did buy some RF transistors and they would hardly make any power after
about 7 MHz and replaced them with some RF Parts company and those had
the full power at 30 MHz where I wanted to use them.
Friend bought some rated for about 5 or 10 watts and all 6 of them were
bad from the start. The first 2 he put in fried his circuit. He
measured the other 4 before instlling them and they were all shorted.

I have seen some pictures of the internals of the 2n3055 transistors
from China and some had a very small silicon area compaired to the
'good' ones. They would test good but probably only good for about 1/2
to 1 amp.