18 Aug
1999
18 Aug
'99
11:54 a.m.
At 06:52 PM 8/18/99 -0400, Allison wrote:
As someone that has wound audio and power transformers
from scratch it's
a pretty trivial task and can be very useful. Used to be a time the
ARRL (USA) Handbook for Radio Amateurs had all the tables. Though given
a random core it's pretty easy work all the numbers out after finding out
if it's big enough.
Allison
Yes. Good numbers to start with for power transformers are (US
measurements, I am sure there are equivalent ones in use elsewhere):
6 turns/volt/square inch of core.
Wattage = 32*(square inch of core)^2
For AWG 23 wire, 1 Amp and area changes by 2x for every 3 gauge numbers.
Winding space is easy to figure out with standard "EI" laminations.
Of course small transformers such as in some wall warts would be a pain!
-Dave