i have a astron 20amp supply

want to replace the iron transformer with a torroid

(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


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


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


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?



thanks

ml wrote:
i have a astron 20amp supply

want to replace the iron transformer with a torroid

Why not an iron toroid?


(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


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


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


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?



thanks


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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

Eeyore wrote in
:



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



This is one of those posts that makes me want to reply like you usually
do. (grahm)

To respond to the main message, you obviously lack the ability to handle
any conversion what so ever. This is demonstrated by your lack of
ability to find standard output toroids and your lack of knowledge of
basic terminology. Though of course it is obvious you once were a wiz at
electronics long in the past, but it has been a while since you practiced
the arcane arts....

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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