N
Norm Dresner
Guest
Exactly what kind of "computer" would use 430V "Computer Grade Caps"???
Electronic Goldmine latest sale brochure.
Norm
Electronic Goldmine latest sale brochure.
Norm
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Dave Platt
Guest
In article <u9bUc.461283$Gx4.26672@bgtnsc04-news.ops.worldnet.att.net>,
Norm Dresner <ndrez@att.net> wrote:
You'll see 'em used in mainframe computers, disk farms/arrays, etc.
These caps are usually used on the primary (high-voltage) side of an
SMPS. They smooth/filter the high-voltage DC which is created by
direct rectification of the AC mains voltage. This high DC voltage is
then fed into the SMPS chopper circuitry and the transformer primary,
and the low-voltage high-amperage output is tapped off of the
secondary and filtered and post-regulated.
I believe the phrase "computer grade" came into use when these SMPS
circuits were first rolled out, to designate caps which were designed
for this sort of application. Older-style electrolytic capacitors
often could not handle the high switching frequencies, and high ripple
currents involved in an SMPS application - they had too high a series
resistance and/or too high an inductance, and they'd overheat and
start blowing boiling electrolyte out of their safety vents. Messy,
and more than a bit scary to be around.
--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
Norm Dresner <ndrez@att.net> wrote:
Any computer with a large, high-amperage switching-mode power supply.Exactly what kind of "computer" would use 430V "Computer Grade Caps"???
You'll see 'em used in mainframe computers, disk farms/arrays, etc.
These caps are usually used on the primary (high-voltage) side of an
SMPS. They smooth/filter the high-voltage DC which is created by
direct rectification of the AC mains voltage. This high DC voltage is
then fed into the SMPS chopper circuitry and the transformer primary,
and the low-voltage high-amperage output is tapped off of the
secondary and filtered and post-regulated.
I believe the phrase "computer grade" came into use when these SMPS
circuits were first rolled out, to designate caps which were designed
for this sort of application. Older-style electrolytic capacitors
often could not handle the high switching frequencies, and high ripple
currents involved in an SMPS application - they had too high a series
resistance and/or too high an inductance, and they'd overheat and
start blowing boiling electrolyte out of their safety vents. Messy,
and more than a bit scary to be around.
--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
R
Roy Smith
Guest
In article <10i2hbndi5kmi73@corp.supernews.com>,
dplatt@radagast.org (Dave Platt) wrote:
in school. We had this huge mongo power supply that we'd wire up to
whatever we could find in the EE lab stockroom. Then we'd go hide
behind a desk or something and flip the switch from a safe distance.
Oh, to be young again!
dplatt@radagast.org (Dave Platt) wrote:
Wimp. Blowing up big capacitors on purpose was great sport when I wasthey'd overheat and
start blowing boiling electrolyte out of their safety vents. Messy,
and more than a bit scary to be around.
in school. We had this huge mongo power supply that we'd wire up to
whatever we could find in the EE lab stockroom. Then we'd go hide
behind a desk or something and flip the switch from a safe distance.
Oh, to be young again!
D
Dave Platt
Guest
In article <roy-985F1E.19473916082004@reader1.panix.com>,
Roy Smith <roy@panix.com> wrote:
Having one go off when were standing by, unaware, would be good for a
few white hairs and a time-quantum shaved off of your life. Having
one go off when you were standing over it, looking down, could be good
for some considerable eye surgery.
--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
Roy Smith <roy@panix.com> wrote:
Yeah, but you were [1] expecting the BOOM, and [2] at a safe distance.they'd overheat and
start blowing boiling electrolyte out of their safety vents. Messy,
and more than a bit scary to be around.
Wimp. Blowing up big capacitors on purpose was great sport when I was
in school. We had this huge mongo power supply that we'd wire up to
whatever we could find in the EE lab stockroom. Then we'd go hide
behind a desk or something and flip the switch from a safe distance.
Having one go off when were standing by, unaware, would be good for a
few white hairs and a time-quantum shaved off of your life. Having
one go off when you were standing over it, looking down, could be good
for some considerable eye surgery.
--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
W
Watson A.Name - \"Watt Su
Guest
"Norm Dresner" <ndrez@att.net> wrote in message
news:u9bUc.461283$Gx4.26672@bgtnsc04-news.ops.worldnet.att.net...
They're used in SMPSes, switch mode power supplies, probably used in
computers. I've got a couple heavy-duty SMPSes from servers, with some
very healthy sized caps like that. The incoming AC is rectified and V
doubled, and the caps are often 470, 680 or 1000 uF at some high voltage
such as that.
But then you never know what you find at Goldmine Electronics, and if it
sounds too good to be true, it probably is.
news:u9bUc.461283$Gx4.26672@bgtnsc04-news.ops.worldnet.att.net...
Exactly what kind of "computer" would use 430V "Computer Grade
Caps"???
Electronic Goldmine latest sale brochure.
Norm
They're used in SMPSes, switch mode power supplies, probably used in
computers. I've got a couple heavy-duty SMPSes from servers, with some
very healthy sized caps like that. The incoming AC is rectified and V
doubled, and the caps are often 470, 680 or 1000 uF at some high voltage
such as that.
But then you never know what you find at Goldmine Electronics, and if it
sounds too good to be true, it probably is.
W
Watson A.Name - \"Watt Su
Guest
"Roy Smith" <roy@panix.com> wrote in message
news:roy-985F1E.19473916082004@reader1.panix.com...
wimpy capacitors! We made our own IEDs! Then we graduated to model
rocketry. See http://www.rrs.org for more info.
news:roy-985F1E.19473916082004@reader1.panix.com...
Don't know about you, but my friends and I didn't bother with blowing upIn article <10i2hbndi5kmi73@corp.supernews.com>,
dplatt@radagast.org (Dave Platt) wrote:
they'd overheat and
start blowing boiling electrolyte out of their safety vents. Messy,
and more than a bit scary to be around.
Wimp. Blowing up big capacitors on purpose was great sport when I was
in school. We had this huge mongo power supply that we'd wire up to
whatever we could find in the EE lab stockroom. Then we'd go hide
behind a desk or something and flip the switch from a safe distance.
Oh, to be young again!
wimpy capacitors! We made our own IEDs! Then we graduated to model
rocketry. See http://www.rrs.org for more info.
M
Michael Black
Guest
"Norm Dresner" (ndrez@att.net) writes:
"computer grade capacitors". These were big, the size of Coke cans,
and had a metal casing and threaded terminals. This was a time when
large capacitance capacitors were relatively rare, because need was
just starting and manufacturers hadn't taken up the task much. In
the hobby magazines, you'd often see power supplies where massive
capacitance was shown, because that was the only way to get low impedance
output. The switchover to regulators to get that low impedance was just
starting. I have one of these "computer grade" capacitors, 10,000 uF
at about 16v, that I bought about 1974 at a hamfest and it was about
the largest capacitance I came across at the time, and it barely had
high enough voltage rating for my 12V supply I built.
Compare it to the average power supply nowadays, where you'll see
that high capacitance, or higher, in a much smaller package and a
higher voltage rating. The manufacturers have gotten good at
supplying such capacitors in a small package.
So I suspect it's just advertising, at least now. THirty five years
ago, likely such capacitors were only appearing in computers. Now
it means nothing, though as others have pointed out, they likely are
intended for switching supplies in computers, though now those computers
are hardly out of the ordinary.
Michael
relatively new in hobby circles, you'd see the surplus dealers sellingExactly what kind of "computer" would use 430V "Computer Grade Caps"???
Electronic Goldmine latest sale brochure.
Norm
The term is old. Thirty-five years ago, when semiconductors were still
"computer grade capacitors". These were big, the size of Coke cans,
and had a metal casing and threaded terminals. This was a time when
large capacitance capacitors were relatively rare, because need was
just starting and manufacturers hadn't taken up the task much. In
the hobby magazines, you'd often see power supplies where massive
capacitance was shown, because that was the only way to get low impedance
output. The switchover to regulators to get that low impedance was just
starting. I have one of these "computer grade" capacitors, 10,000 uF
at about 16v, that I bought about 1974 at a hamfest and it was about
the largest capacitance I came across at the time, and it barely had
high enough voltage rating for my 12V supply I built.
Compare it to the average power supply nowadays, where you'll see
that high capacitance, or higher, in a much smaller package and a
higher voltage rating. The manufacturers have gotten good at
supplying such capacitors in a small package.
So I suspect it's just advertising, at least now. THirty five years
ago, likely such capacitors were only appearing in computers. Now
it means nothing, though as others have pointed out, they likely are
intended for switching supplies in computers, though now those computers
are hardly out of the ordinary.
Michael
W
Watson A.Name - \"Watt Su
Guest
"Michael Black" <et472@FreeNet.Carleton.CA> wrote in message
news:cfroh3$qkq$1@freenet9.carleton.ca...
used 'telephone grade' electrolytics, which meant that the caps were
made to last for much longer than the usual commercial caps. The gray
WeCo caps come to mind.
there is less chance of the capacitor going bad.
> Michael
news:cfroh3$qkq$1@freenet9.carleton.ca...
I remember that commercial equipment makers often offered equipment that"Norm Dresner" (ndrez@att.net) writes:
Exactly what kind of "computer" would use 430V "Computer Grade
Caps"???
Electronic Goldmine latest sale brochure.
Norm
The term is old. Thirty-five years ago, when semiconductors were
still
relatively new in hobby circles, you'd see the surplus dealers selling
"computer grade capacitors". These were big, the size of Coke cans,
and had a metal casing and threaded terminals. This was a time when
large capacitance capacitors were relatively rare, because need was
just starting and manufacturers hadn't taken up the task much. In
used 'telephone grade' electrolytics, which meant that the caps were
made to last for much longer than the usual commercial caps. The gray
WeCo caps come to mind.
Or making a purer aluminum for the plates and purer electrolyte so thatthe hobby magazines, you'd often see power supplies where massive
capacitance was shown, because that was the only way to get low
impedance
output. The switchover to regulators to get that low impedance was
just
starting. I have one of these "computer grade" capacitors, 10,000 uF
at about 16v, that I bought about 1974 at a hamfest and it was about
the largest capacitance I came across at the time, and it barely had
high enough voltage rating for my 12V supply I built.
Compare it to the average power supply nowadays, where you'll see
that high capacitance, or higher, in a much smaller package and a
higher voltage rating. The manufacturers have gotten good at
supplying such capacitors in a small package.
there is less chance of the capacitor going bad.
Nowadays even the wall warts are switching power supplies.So I suspect it's just advertising, at least now. THirty five years
ago, likely such capacitors were only appearing in computers. Now
it means nothing, though as others have pointed out, they likely are
intended for switching supplies in computers, though now those
computers
are hardly out of the ordinary.
> Michael
F
Franc Zabkar
Guest
On 17 Aug 2004 01:54:43 GMT, et472@FreeNet.Carleton.CA (Michael Black)
put finger to keyboard and composed:
http://members.optusnet.com.au/~fzabkar/screwcaps70.jpg (135KB)
- Franc Zabkar
--
Please remove one 's' from my address when replying by email.
put finger to keyboard and composed:
Remember the Sprague Compulytic and Powerlytic range?"Norm Dresner" (ndrez@att.net) writes:
Exactly what kind of "computer" would use 430V "Computer Grade Caps"???
Electronic Goldmine latest sale brochure.
Norm
The term is old. Thirty-five years ago, when semiconductors were still
relatively new in hobby circles, you'd see the surplus dealers selling
"computer grade capacitors". These were big, the size of Coke cans,
and had a metal casing and threaded terminals.
http://members.optusnet.com.au/~fzabkar/screwcaps70.jpg (135KB)
- Franc Zabkar
--
Please remove one 's' from my address when replying by email.
P
Peter A Forbes
Guest
On Wed, 18 Aug 2004 06:00:30 +1000, Franc Zabkar <fzabkar@optussnet.com.au>
wrote:
Peter
--
Peter & Rita Forbes
diesel@easynet.co.uk
Engine pages for preservation info:
http://www.oldengine.org/members/diesel
wrote:
Still got a box of them on the shelf at the factory, 6800/40V IIRC.Remember the Sprague Compulytic and Powerlytic range?
http://members.optusnet.com.au/~fzabkar/screwcaps70.jpg (135KB)
- Franc Zabkar
Peter
--
Peter & Rita Forbes
diesel@easynet.co.uk
Engine pages for preservation info:
http://www.oldengine.org/members/diesel