thanks very much for the tips appreciate your advice

i am in nyc btw

again thanks

In article ,


Eeyore wrote:

ml wrote:

i have a astron 20amp supply

want to replace the iron transformer with a torroid

It's not an iron transformer, it's an EI laminated transformer ( presumably )
and it's made with steel laminations and the word you're looking for is
toroid
with one R btw.


(to reduce noise)

the primary needs to be 120vac 60hz

not yet sure what their exact 2ndary is but guess it's got to be around
13v and able to handle the 25amp dc 20amp cont

I suggest you measure it ! is the load 25 or 20 A DC ?


is their any rules of thumb doing such a replacement or do i just match
the original spec's to the new toroid?

Basically yes - but do specify that's it has to supply a capacitor input
filter
( I presume it does ) since the rms currrent is different to a resistive
load.
This affects the required VA rating.

25A DC load ~ 40-45A AC rating btw ( crest factor correction ).


any good places for such a torrid? i couldn't find any in this range

Loads, but where are you, There's no point in me guessing.


btw

how do you mount one in a sheet metal enclosure? i presume the unit
can't come close to the metal case so i guess a small raised plastic
block and tie wraps?

There are several ways. I like the centre resin filled so you can bolt it
down
myself, otherwise a circular 'dish' is the normal way.

Graham