The 280 pound capacitor

[Tim Williams]

"Bert Hickman" <bert-hickman@comcast.net> wrote in message
news:Wvydna-H_99eBafEnZ2dnUU7-anNnZ2d@giganews.com...

I have a 280-pound capacitor, four of them in fact.
Well, they must weigh something in that vicinity.
They cost $500 each, including pallet shipping.

The physically largest capacitor I ever saw in person was a PIO type
rated IIRC for a couple of uF at several kV; it weighed about as much as
a bowling ball and was about the same size


Our 170 pound energy discharge capacitors, each 70 uF at 12 kVDC:
http://capturedlightning.com/photos/Energy_Discharge_Caps/MAXCAP3.JPG

I've worked with capacitors bigger than that, although I think they were in
sections so maybe it's not technically true to say "bigger capacitor"
(singular). :^) Ratings were around 100s uF, 2000V, lots of amps.

Tim

--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Contract Design
Website: http://seventransistorlabs.com

 

[Jeff Liebermann]

On Fri, 09 Jun 2017 09:16:52 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:
(...)

A bit more on the cost of a replacement capacitor. A company that I
worked for in about 1977 was having a similar issue selling
replacement and repair components to its dealers. So, I calculated
what it cost the company to sell an empty box. That's a repair
component that costs zero dollars to purchase and requires no
manufacturing. However, it does carry all the overhead involved in
shipping a product, such as incoming inspection, QA inspection,
inventory control, warehousing, packing, order taking, boxing,
documentation, billing, handling, etc. I estimated $75 cost to
shipping (not including postage). My guess(tm) is that it would be
about 4 times that (due mostly to increased overhead and inflation)
today. That would be $300 to ship an empty box today, which is about
what Marconi is charging.

We "solved" the problem by offering the dealers almost any quantity of
the smaller parts involved for about the same price. Or, we would
throw in a handful of random floor sweepings with a little of
everything we thought might be useful. Either way, the minimum price
to ship anything remained at $75.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Winfield Hill]

Bert Hickman wrote...

bitrex wrote:
On 06/08/2017 01:39 PM, Winfield Hill wrote:
Cursitor Doom wrote...

I tore down a Marconi signal generator today. ...
faulty smoothing cap in the PSU .. GBP280.

I have a 280-pound capacitor, four of them in fact.
Well, they must weigh something in that vicinity.
They cost $500 each, including pallet shipping.

The physically largest capacitor I ever saw in person was a PIO type
rated IIRC for a couple of uF at several kV; it weighed about as much as
a bowling ball and was about the same size

Our 170 pound energy discharge capacitors, each 70 uF
at 12 kVDC:
http://capturedlightning.com/photos/Energy_Discharge_Caps/MAXCAP3.JPG

Whoa, you have 11 of them! My caps look like those.


--
Thanks,
- Win

 

[Cursitor Doom]

On Fri, 09 Jun 2017 08:00:30 -0400, bitrex wrote:

Probably because they got a bunch of large value weird-ass caps cheap
and that's what they use in everything. Like a guy who asked me why they
used a 1N4002 in this one mass-produced rack effects box when a 1N4001
would've been fine from a ratings perspective and it's cuz "that's what
they use in everything"

That, unlike most everything else you post, makes sense.

 

[Cursitor Doom]

On Fri, 09 Jun 2017 09:16:52 -0700, Jeff Liebermann wrote:

Carefully remove the base from the capacitor, preserving only the base
and the can. If you're really careful, you might be able to also save
the vinyl insulator. Tear out the guts and throw it away. Install the
replacement physically smaller capacitor inside the can, connecting the
capacitor leads to the base to match the original. Solder it back onto
the PCB and you're done.

An old friend of mine who collected vintage broadcast radios would use
this technique when re-furbing them to keep up the appearance of
originality. I never considered doing this with non-classic gear before,
but it does make sense as the existing through holes can be used without
needing to accommodate the different lead spacings of the new component.
Thank you, Jeff.

 

[bitrex]

On 06/09/2017 02:43 PM, Cursitor Doom wrote:

On Fri, 09 Jun 2017 08:00:30 -0400, bitrex wrote:

Probably because they got a bunch of large value weird-ass caps cheap
and that's what they use in everything. Like a guy who asked me why they
used a 1N4002 in this one mass-produced rack effects box when a 1N4001
would've been fine from a ratings perspective and it's cuz "that's what
they use in everything"

That, unlike most everything else you post, makes sense.

I may be a "communist", but I do understand economies of scale. Build
everything out of LM324s, TL431s, and 555 timers if you can, so long as
it meets the spec.

The old '324 and 555 are sort of disparaged around here, but there's a
reason they're made in their billions each year and it's not because of
sales driven by hobbyists.

I think the reason a lot of software is so bad is because lines of code
are basically free. Hey! There's a library for that, don't "reinvent the
wheel." So what if it's 40,000 lines long and was written by God knows who

 

[Ralph Barone]

Tim Williams <tiwill@seventransistorlabs.com> wrote:

"Bert Hickman" <bert-hickman@comcast.net> wrote in message
news:Wvydna-H_99eBafEnZ2dnUU7-anNnZ2d@giganews.com...
I have a 280-pound capacitor, four of them in fact.
Well, they must weigh something in that vicinity.
They cost $500 each, including pallet shipping.

The physically largest capacitor I ever saw in person was a PIO type
rated IIRC for a couple of uF at several kV; it weighed about as much as
a bowling ball and was about the same size


Our 170 pound energy discharge capacitors, each 70 uF at 12 kVDC:
http://capturedlightning.com/photos/Energy_Discharge_Caps/MAXCAP3.JPG

I've worked with capacitors bigger than that, although I think they were in
sections so maybe it's not technically true to say "bigger capacitor"
(singular). :^) Ratings were around 100s uF, 2000V, lots of amps.

Tim

66 uF, 276 kV, 3000 A
but that was an aggregation of multiple cans.

 

[Cursitor Doom]

On Fri, 09 Jun 2017 18:32:35 -0400, bitrex wrote:

I think the reason a lot of software is so bad is because lines of code
are basically free. Hey! There's a library for that, don't "reinvent the
wheel." So what if it's 40,000 lines long and was written by God knows
who

Er, yes, good point but not sure what it's got to do with the subject
matter of this thread.

 

[Winfield Hill]

Ralph Barone wrote...

Tim Williams <tiwill@seventransistorlabs.com> wrote:
"Bert Hickman" <bert-hickman@comcast.net> wrote in message
news:Wvydna-H_99eBafEnZ2dnUU7-anNnZ2d@giganews.com...
I have a 280-pound capacitor, four of them in fact.
Well, they must weigh something in that vicinity.
They cost $500 each, including pallet shipping.

The physically largest capacitor I ever saw in person was a PIO type
rated IIRC for a couple of uF at several kV; it weighed about as much as
a bowling ball and was about the same size


Our 170 pound energy discharge capacitors, each 70 uF at 12 kVDC:
http://capturedlightning.com/photos/Energy_Discharge_Caps/MAXCAP3.JPG

I've worked with capacitors bigger than that, although I think they were in
sections so maybe it's not technically true to say "bigger capacitor"
(singular). :^) Ratings were around 100s uF, 2000V, lots of amps.

Tim

66 uF, 276 kV, 3000 A
but that was an aggregation of multiple cans.

Did the series caps have voltage-equalizing mediation?


--
Thanks,
- Win

 

[Ralph Barone]

Winfield Hill <hill@rowland.harvard.edu> wrote:

Ralph Barone wrote...

Tim Williams <tiwill@seventransistorlabs.com> wrote:
"Bert Hickman" <bert-hickman@comcast.net> wrote in message
news:Wvydna-H_99eBafEnZ2dnUU7-anNnZ2d@giganews.com...
I have a 280-pound capacitor, four of them in fact.
Well, they must weigh something in that vicinity.
They cost $500 each, including pallet shipping.

The physically largest capacitor I ever saw in person was a PIO type
rated IIRC for a couple of uF at several kV; it weighed about as much as
a bowling ball and was about the same size


Our 170 pound energy discharge capacitors, each 70 uF at 12 kVDC:
http://capturedlightning.com/photos/Energy_Discharge_Caps/MAXCAP3.JPG

I've worked with capacitors bigger than that, although I think they were in
sections so maybe it's not technically true to say "bigger capacitor"
(singular). :^) Ratings were around 100s uF, 2000V, lots of amps.

Tim

66 uF, 276 kV, 3000 A
but that was an aggregation of multiple cans.

Did the series caps have voltage-equalizing mediation?

This was an AC application (partially cancel the series inductance of a 500
kV power line), so voltage equalization wasn't a huge concern. The
individual cans did have bleed resistors inside, but those were to meet the
requirement that a can would have a safe voltage on it 15 minutes after
deenergization. The cans were also arranged in an H configuration with a
CT to measure the unbalance current between the four sections. If the
unbalance exceeded a critical value, the bank would be tripped out.