M
Motty
Guest
Does anyone know of a fairly inexpensive one to get and more
importantly WHERE to get it?
Thanks
importantly WHERE to get it?
Thanks
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L
Lizard Blizzard
Guest
Motty wrote:
http://www.zettlermagnetics.com/pfppcbt.htm
http://www.entcorp.com/Dwnlds/entxfrmr.pdf
etc.
etc.
etc.
--
----------------(from OED Mini-Dictionary)-----------------
PUNCTUATION - Apostrophe
Incorrect uses: (i) the apostrophe must not be used with a plural
where there is no possessive sense, as in ~tea's are served here~;
(ii) there is no such word as ~her's, our's, their's, your's~.
Confusions: it's = it is or it has (not 'belonging to it'); correct
uses are ~it's here~ (= it is here); ~it's gone~ (= it has gone);
but ~the dog wagged its tail~ (no apostrophe).
----------------(For the Apostrophe challenged)----------------
From a fully deputized officer of the Apostrophe Police!
<<Spammers use Weapons of Mass Distraction!>>
I bought some batteries, but they weren't included,
so I had to buy them again.
-- Steven Wright
FOR SALE: Nice parachute: never opened - used once.
(Problem) Evidence of leak on right main landing gear
(Solution) Evidence removed
F
o
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f
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http://www.jmtransformer.com/splitbobbinpower.htmlDoes anyone know of a fairly inexpensive one to get and more
importantly WHERE to get it?
Thanks
http://www.zettlermagnetics.com/pfppcbt.htm
http://www.entcorp.com/Dwnlds/entxfrmr.pdf
etc.
etc.
etc.
--
----------------(from OED Mini-Dictionary)-----------------
PUNCTUATION - Apostrophe
Incorrect uses: (i) the apostrophe must not be used with a plural
where there is no possessive sense, as in ~tea's are served here~;
(ii) there is no such word as ~her's, our's, their's, your's~.
Confusions: it's = it is or it has (not 'belonging to it'); correct
uses are ~it's here~ (= it is here); ~it's gone~ (= it has gone);
but ~the dog wagged its tail~ (no apostrophe).
----------------(For the Apostrophe challenged)----------------
From a fully deputized officer of the Apostrophe Police!
<<Spammers use Weapons of Mass Distraction!>>
I bought some batteries, but they weren't included,
so I had to buy them again.
-- Steven Wright
FOR SALE: Nice parachute: never opened - used once.
(Problem) Evidence of leak on right main landing gear
(Solution) Evidence removed
F
o
d
d
e
r
f
o
r
s
t
u
p
i
d
"
n
o
t
e
n
o
u
g
h
i
n
c
l
d
u
d
e
d
t
e
x
t
"
e
r
r
o
r
m
s
g
..
W
Walter Harley
Guest
"Motty" <tom.lassiter@att.net> wrote...
By the way, why do you need one? Would a common 24V xfmr not work, with a
different rectification scheme (e.g., halfwave instead of fullwave
rectifier)? (Or even a voltage doubler? Or a DC-DC converter? Or...)
IME, most (not all) the time, if I'm having a hard time finding the part I
need, it's because I'm solving a common problem in an uncommon way... and if
there's a common way, it's nearly always going to be easier and cheaper and
more reliable. Unless my problem is really uncommon, and most of 'em
aren't.
How much current?Does anyone know of a fairly inexpensive one to get and more
importantly WHERE to get it?
By the way, why do you need one? Would a common 24V xfmr not work, with a
different rectification scheme (e.g., halfwave instead of fullwave
rectifier)? (Or even a voltage doubler? Or a DC-DC converter? Or...)
IME, most (not all) the time, if I'm having a hard time finding the part I
need, it's because I'm solving a common problem in an uncommon way... and if
there's a common way, it's nearly always going to be easier and cheaper and
more reliable. Unless my problem is really uncommon, and most of 'em
aren't.
M
Motty
Guest
"Walter Harley" <walterh@cafewalterNOSPAM.com> wrote in message news:<vpblk0sjagtcb5@corp.supernews.com>...
supply I want to build. It simply plugs into a bridge network via a
center tap and then feeds voltage regulators to get the +24 and -24.
If you know of a simpler or more elegant way to do this then by all
means, let me know. I really don't want to work with DC-DC
converters. I have used them in the past and have not been able to
get enough current out of them. The ones with discrete inductors were
the worst. But please let me know if you have any suggestions.
Thanks
Current...about 1.5 - 2 amps. I need it for a bipolar 24 volt power"Motty" <tom.lassiter@att.net> wrote...
Does anyone know of a fairly inexpensive one to get and more
importantly WHERE to get it?
How much current?
By the way, why do you need one? Would a common 24V xfmr not work, with a
different rectification scheme (e.g., halfwave instead of fullwave
rectifier)? (Or even a voltage doubler? Or a DC-DC converter? Or...)
IME, most (not all) the time, if I'm having a hard time finding the part I
need, it's because I'm solving a common problem in an uncommon way... and if
there's a common way, it's nearly always going to be easier and cheaper and
more reliable. Unless my problem is really uncommon, and most of 'em
aren't.
supply I want to build. It simply plugs into a bridge network via a
center tap and then feeds voltage regulators to get the +24 and -24.
If you know of a simpler or more elegant way to do this then by all
means, let me know. I really don't want to work with DC-DC
converters. I have used them in the past and have not been able to
get enough current out of them. The ones with discrete inductors were
the worst. But please let me know if you have any suggestions.
Thanks
D
Dbowey
Guest
Tom posted:
<< Current...about 1.5 - 2 amps. I need it for a bipolar 24 volt power supply
I want to build. It simply plugs into a bridge network via a center tap and
then feeds voltage regulators to get the +24 and -24. If you know of a simpler
or more elegant way to do this then by all means, let me know. >>
That's an elegant approach. Slightly less-so is to use two transformers, of
course.
On the otherhand, if you happen to be in the Portland Oregon area, drop me an
email. My junkbox, full of free things, probably includes what you are
seeking, but I do_not_ship.
Don
<< Current...about 1.5 - 2 amps. I need it for a bipolar 24 volt power supply
I want to build. It simply plugs into a bridge network via a center tap and
then feeds voltage regulators to get the +24 and -24. If you know of a simpler
or more elegant way to do this then by all means, let me know. >>
That's an elegant approach. Slightly less-so is to use two transformers, of
course.
On the otherhand, if you happen to be in the Portland Oregon area, drop me an
email. My junkbox, full of free things, probably includes what you are
seeking, but I do_not_ship.
Don
W
Walter Harley
Guest
"Motty" <tom.lassiter@att.net> wrote...
it's hard to find 48VCT 2A transformers.
Instead, use a 24V 4A transformer (ignore the center tap if it has one), and
a half-wave rectifier: tie one side of the secondary to ground, and take two
diodes from the other side, pointed in opposite directions, one connected to
the + filter cap, one to the - filter cap.
(If that doesn't make sense let me know and I'll post an ASCII schematic.)
This is just as efficient as the bridge rectifier (actually slightly more):
you're using each half-wave, not throwing anything away like you would if
you used a single half-wave rectifier. And you've only got one diode drop,
rather than two.
The disadvantage is that you're charging the caps at 60Hz rather than 120Hz,
so you've got more ripple current to contend with, so might need bigger
filter caps and bigger wires. Basically, on each half-wave, you're dumping
all the current into one cap, rather than half the current into each of the
two caps.
So, a 48VCT 2A transformer, through a bridge rectifier. But as you observe,Current...about 1.5 - 2 amps. I need it for a bipolar 24 volt power
supply I want to build. It simply plugs into a bridge network via a
center tap and then feeds voltage regulators to get the +24 and -24.
If you know of a simpler or more elegant way to do this then by all
means, let me know.
it's hard to find 48VCT 2A transformers.
Instead, use a 24V 4A transformer (ignore the center tap if it has one), and
a half-wave rectifier: tie one side of the secondary to ground, and take two
diodes from the other side, pointed in opposite directions, one connected to
the + filter cap, one to the - filter cap.
(If that doesn't make sense let me know and I'll post an ASCII schematic.)
This is just as efficient as the bridge rectifier (actually slightly more):
you're using each half-wave, not throwing anything away like you would if
you used a single half-wave rectifier. And you've only got one diode drop,
rather than two.
The disadvantage is that you're charging the caps at 60Hz rather than 120Hz,
so you've got more ripple current to contend with, so might need bigger
filter caps and bigger wires. Basically, on each half-wave, you're dumping
all the current into one cap, rather than half the current into each of the
two caps.