Hello Group
and a very merry Christmas to one and all.
If anyone is planning a little home construction over the holiday period you
may like to look at a FET marketed by RS Components as an alternative to the
IRFP450.
STW34NB20 RS catalogue number 313-2920.
Voltage 500 V
Current 34 Amps
Power Diss 180 Watts
Rds ON 0.08 Ohms
Package TO247 as IRFP450 etc. Drain connected to tab.
Price #2.78 + VAT in 1 off.
A small test circuit using two of these in class D comfortably produces 350
Watts at 86% efficiency after the low pass filter. I've tested with supplies
from 24 to 60V and with qrss.
As the Rds on is less than a quarter of the IRFP450, the device may also be
OK for lower Voltage operation.
I've also recently purchased a supply of 3C85 toroids from Philips.
As there was a minimum order charge I've bought some of the 58mm cores and
some smaller 15 x 8 x 5.5mm (OD ID H) which are very useful for
directional coupler elements. If a VSWR bridge is on your "to be built" list,
and you need a core, let me know.
73 es a "bug free" y2k
David G0MRF
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