Re. 28v switcher psu
 

ok then MikeN i guess you were moding a psu, was it a computer psu and if so
what was your final voltage, asking as i would like to know how many
secondary turns you wound for your required voltage, asumming running at
about 33khz 230v ac before rectifier etc...
oh MEK?? i have cellulose thinners to hand..but no transformer to split
untill i get my hands on some more psu's, (when i venture back into the
attic!)
sorry if these questions sound simple, but i am really keen in not having to
wind douzens of transformers before i get it correct..
All else has been done ie caps beefed up from 16v to 35v, feedback crt
modded.etc......I will be writing up when finished and putting on web page
in case of any interest..

simon

ok i know what mek is now thanks..helps if i read previous posts first..
"zindazenda" wrote in message
...
ok then MikeN i guess you were moding a psu, was it a computer psu and if
so
what was your final voltage, asking as i would like to know how many
secondary turns you wound for your required voltage, asumming running at
about 33khz 230v ac before rectifier etc...
oh MEK?? i have cellulose thinners to hand..but no transformer to split
untill i get my hands on some more psu's, (when i venture back into the
attic!)
sorry if these questions sound simple, but i am really keen in not having
to
wind douzens of transformers before i get it correct..
All else has been done ie caps beefed up from 16v to 35v, feedback crt
modded.etc......I will be writing up when finished and putting on web page
in case of any interest..

simon

ok i know what mek is now thanks..helps if i read previous posts first..
"zindazenda" wrote in message
...
ok then MikeN i guess you were moding a psu, was it a computer psu and if
so
what was your final voltage, asking as i would like to know how many
secondary turns you wound for your required voltage, asumming running at
about 33khz 230v ac before rectifier etc...
oh MEK?? i have cellulose thinners to hand..but no transformer to split
untill i get my hands on some more psu's, (when i venture back into the
attic!)
sorry if these questions sound simple, but i am really keen in not having
to
wind douzens of transformers before i get it correct..
All else has been done ie caps beefed up from 16v to 35v, feedback crt
modded.etc......I will be writing up when finished and putting on web page
in case of any interest..

simon

My analysis of the few switchers from PCs is that
the windings are
about 4V/turn. This assumes one takes the center
point of the mains caps
as the primary voltage switched. 42 to 44 turns, I
counted.
The secondary seems to have plenty of lee-way in
voltage range
on the assumption that on full load only will it
be a 50% duty
cycle. I'm sure someone will correct me it I'm
wrong! :-)

Cheers

zindazenda wrote:

ok then MikeN i guess you were moding a psu, was it a computer psu and if so
what was your final voltage, asking as i would like to know how many
secondary turns you wound for your required voltage, asumming running at
about 33khz 230v ac before rectifier etc...
oh MEK?? i have cellulose thinners to hand..but no transformer to split
untill i get my hands on some more psu's, (when i venture back into the
attic!)
sorry if these questions sound simple, but i am really keen in not having to
wind douzens of transformers before i get it correct..
All else has been done ie caps beefed up from 16v to 35v, feedback crt
modded.etc......I will be writing up when finished and putting on web page
in case of any interest..

simon
Murray Kelly vk4aok

My analysis of the few switchers from PCs is that
the windings are
about 4V/turn. This assumes one takes the center
point of the mains caps
as the primary voltage switched. 42 to 44 turns, I
counted.
The secondary seems to have plenty of lee-way in
voltage range
on the assumption that on full load only will it
be a 50% duty
cycle. I'm sure someone will correct me it I'm
wrong! :-)

Cheers

zindazenda wrote:

ok then MikeN i guess you were moding a psu, was it a computer psu and if so
what was your final voltage, asking as i would like to know how many
secondary turns you wound for your required voltage, asumming running at
about 33khz 230v ac before rectifier etc...
oh MEK?? i have cellulose thinners to hand..but no transformer to split
untill i get my hands on some more psu's, (when i venture back into the
attic!)
sorry if these questions sound simple, but i am really keen in not having to
wind douzens of transformers before i get it correct..
All else has been done ie caps beefed up from 16v to 35v, feedback crt
modded.etc......I will be writing up when finished and putting on web page
in case of any interest..

simon
Murray Kelly vk4aok