Film capacitor as power-supply filter

[Piotr Wyderski]

John Larkin wrote:

> https://www.dropbox.com/s/dlet57gmlntxx9h/Ccap_Leakage.JPG?dl=0

A 50V fed with 250V? What are the exact reasons behind going *that* far?
Curiosity where the limit is is one thing, but I suppose there was
something more. Are you abusing them in production for some reason?

Best regards, Piotr

 

[Piotr Wyderski]

Phil Allison wrote:

> ** Have you *never* seen a published project in a magazine or on line ?

I have several such projects in my portfolio, but all in Polish (because
the magazine is Polish). One of them is the magnetic
amplifier-controlled synchronous rectifier. I posted pics and schematics
here.
I can send you the PDFs if you wish.

One was forbidden to use exotic, hard to get parts or expect builders
to own more than a DMM.

This is too stringent a requirement, given the prices of the Rigol
scopes. It would be hard to debug my circuit with a DMM, too many
windings with important polarities.

Best regards, Piotr

 

On Monday, 21 October 2019 09:31:48 UTC+1, Phil Allison wrote:

Phil Allison wrote:

** Not complaining about anything like that.

Just the ingenuous nature of JLs malicious trap request.


** Ooops - should be "disingenuous" .

either describes you well enough

 

[Phil Allison]

Piotr Wyderski is Nuts wrote:

------------------------------

** Have you *never* seen a published project in a magazine or on line ?

I have several such projects in my portfolio, but all in Polish

** So not published by any leading national magazine.

One was forbidden to use exotic, hard to get parts or expect builders
to own more than a DMM.

This is too stringent a requirement, given the prices of the Rigol
scopes.

** Wot is this Nutter on ??



...... Phil

 

[Cursitor Doom]

On Mon, 21 Oct 2019 11:39:11 +0200, Piotr Wyderski wrote:

A 50V fed with 250V? What are the exact reasons behind going *that* far?
Curiosity where the limit is is one thing, but I suppose there was
something more. Are you abusing them in production for some reason?

Let's just be thankful he doesn't have access to any laboratory
rodents. :-D




--
This message may be freely reproduced without limit or charge only via
the Usenet protocol. Reproduction in whole or part through other
protocols, whether for profit or not, is conditional upon a charge of
GBP10.00 per reproduction. Publication in this manner via non-Usenet
protocols constitutes acceptance of this condition.

 

[Winfield Hill]

Phil Allison wrote...

You can make a 100nF Green Cap smoke and explode with a
40W bench amplifier and a series inductor of a few mH
operating at resonance.

Good cheap fun.

The caps can easily have Q in excess of 1000. I have
made inductors with Q that high, with litz wire, etc.,
but most are much lower. But even Q=100 can potentially
turn 35 volts into over 3.5 kV. However, high Zout of
the amplifier is a severe Q limitation. After solving
that, you have to deal with high resonate circulating
currents, and power dissipation in the inductors. If
your capacitor goes first, that can save the inductor.

This scheme is most useful when driving piezo elements,
where power injected into the coupled medium limits the
Q and maximum voltage. E.g., my acoustic oceangraphic
instruments in the 80s, and sonoluminescence experiments
in the 90s, looking for the supposed neutrons, hahaha.


--
Thanks,
- Win

 

[Winfield Hill]

Phil Allison wrote...

https://au.mouser.com/ProductDetail/KEMET/C4AQCBW5200A3FJ?qs=sGAEpiMZZMv1cc3ydrPrF95ZAHiPXMKgQ3r3TgzZkS816veTKZI9aw%3D%3D

That's a good find. Rather large: 20x42x40mm high.


--
Thanks,
- Win

 

On 21 Oct 2019 05:35:35 -0700, Winfield Hill <winfieldhill@yahoo.com>
wrote:

Phil Allison wrote...

You can make a 100nF Green Cap smoke and explode with a
40W bench amplifier and a series inductor of a few mH
operating at resonance.

Good cheap fun.

The caps can easily have Q in excess of 1000. I have
made inductors with Q that high, with litz wire, etc.,
but most are much lower. But even Q=100 can potentially
turn 35 volts into over 3.5 kV. However, high Zout of
the amplifier is a severe Q limitation.

Zout doesn't matter. Q doesn't matter. All you need is current.




--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

On Mon, 21 Oct 2019 11:39:11 +0200, Piotr Wyderski
<peter.pan@neverland.mil> wrote:

John Larkin wrote:

https://www.dropbox.com/s/dlet57gmlntxx9h/Ccap_Leakage.JPG?dl=0

A 50V fed with 250V? What are the exact reasons behind going *that* far?

To see what would happen, of course. If it's set up, and that knob is
there, why not turn it? Fear of destroying a 2 cent capacitor? Fear of
a lethal explosion?

Curiosity where the limit is is one thing, but I suppose there was
something more. Are you abusing them in production for some reason?

I rarely use caps beyond rated voltage. There's seldom a reason to do
that. There are times to use parts past ratings, but only if the
payoff is big and you do know where the failure limits are.

There are also parts that I won't use at max ratings.

Ceramic capacitor c-v nonlinearity can be a problem, or it can be
useful.



--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

On Mon, 21 Oct 2019 02:58:51 -0700 (PDT), Phil Allison
<pallison49@gmail.com> wrote:

Piotr Wyderski is Nuts wrote:

------------------------------



** Have you *never* seen a published project in a magazine or on line ?

I have several such projects in my portfolio, but all in Polish


** So not published by any leading national magazine.



One was forbidden to use exotic, hard to get parts or expect builders
to own more than a DMM.

This is too stringent a requirement, given the prices of the Rigol
scopes.


** Wot is this Nutter on ??



..... Phil

Someone could set up a serious electronic lab for around $600 maybe.
Really serious, a few thousand.





--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

On Sun, 20 Oct 2019 21:25:06 -0700 (PDT), Phil Allison
<pallison49@gmail.com> wrote:

jla...@highlandsniptechnology.com wrote:

-------------------------------------------


Truth, in this newsgroup, is designing electronic circuits that work.


** A pretentious claim that simply has no basis in reality.

JL loves to post them, passes for wisdom on planet Larkin.



Design something that works. Post it here.



** How to get rid of 10 pounds of ugly fat ?

Cut your head off.



** That one went over JL's head like a Scud missile ....

That was a corny attempt at humor whan I was a kid. Maybe it has
recently propagated to Australia.

This group is like a tennis group where nobody plays tennis, or a
fishing group where nobody has ever fished.


** More of JL's fake wisdom plus a context shift = complete nonsense.



FYI to all:


-----------------------------------------------------------------

In nearly 20 years I have not seen even ONE original design posted here, complete with schematics, photos and justifications for each component choice and topology used. So I am not gonna be the one to break with that great tradition.
-----------------------------------------------------------------

I've posted scores of original schematics,


** LOL - hand drawn fragments of ideas are not "designs".

They are ideas, which is what electronoc designers start with when
they are brainstorming. Fragments can be evolved or rejected or
trigger other, sometimes very different ideas.

Brainstorming is a group of people having fun with ideas. You couldn't
do it. You are angry and hostile and want everything to be a Heathkit
manual. Some people poison brainstorming, and poison all stages of
electronic design.

You asked for a "DESIGN" - fuckhead.

Published DESIGNS contain all the things I mentioned and more.

What project have you had published and been paid for?

I just manufacture them and sell them. I do post some ideas and
schematics and pictures of actual products here, when I think it would
be helpful and not harm my business.

Care to post a link?

You *maliciously* snipped all reference to the ones I had published.

Must have missed them. Please repost the links.

-----------------------------------------------------------------


and scores of photos of real stuff I've designed,


** Again, no-one can sensibly judge a design from a pic of some a PCB.


and scores of Spice sims.


** Nothing faintly like a "design".

Sims are all 99% worthless.

Good grief, that's an interesting statement. Do you ever run Spice?

Others have posted, freely given away, as many.


** But no complete designs one could sensibly construct.

Again, buy a kit if you want to build something without having to
understand it.

Have you seen Win's HV amps, or
Phil Hobbs low-noise circuits, posted recently?


** Spice listing are NOT designs.

I think they are.

Win's HV lab amp looks like a nightmare.

It's not my schematic style, but it's original, correct, and it works.

I prefet to waste more paper, spread things across less-populated
sheets. Thet leaves more room for scribbles on the bench.

Plus, the complete nonsense he posted about a on-line design that was in fact NOT mine was absurd. I shot it to pieces and so he ignored me.

Possibly you re-discovered something. That happens a lot.

Wot an utter ass.

Not a bit, but your shrieking and swearing does sometimes put people
off. Why do you do that? It can't make you any happier.

I don't furnish detailed "justifications";

** Cos you haven't got nay.

My stuff works and people buy it, and keep buying it. Do you contend
that I don't understand it? That's silly.

(Well, OK, sometimes I don't understand it. I'm just an engineer.)

The reasoning behind a design decision is usually non obvious to outsiders and crucial - cos it may be very good or very bad. A simple fact JLs raging ASD and pig arrogance prevents him from knowing.

The fool has no credible theory of thought - you see.

Some, or a lot, of what I do is instinct. Sorry. The solution space
for even a modest electronic design is way too large to be searched by
any canned procedure. It requires most of a brain to be working as a
quantum computer, encompassing a lot of possibilities in parallel.
That concept annoys a lot of people who want everything to be just so.
Sorry.

"Theory of thought" is exactly what I don't want.

I assume that competent
engineers can look at a schematic and figure out what's going on, and
improve any idea that they want to.


** That barking mad idea is exactly what I am saying is 100% WRONG !!

I can see the problem here. You want every circuit concept to be
explained in detail, with values, like in some old HP manual.

Sorry.



--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

On Mon, 21 Oct 2019 00:14:05 -0700 (PDT), Phil Allison
<pallison49@gmail.com> wrote:

Bill Sloman wrote:

-------------------

Nobody is going to treat Phil Allison as a beginner.


** Happens here daily by Win, John and Phil H.

The Three Stooges.


He's not complaining about not having his hand held,
but rather the absence of proper documentation.

** Not complaining about anything like that.

Just the ingenuous nature of JLs malicious trap request.


He may be asking a bit much. Proper documentation is bulky.


** Have you *never* seen a published project in a magazine or on line ?

Ones I did for EA magazine consisted of 2 to 3 thousand words, colour pics, a PCB pattern and component layout, specifications list, block diagrams and of course a full schematic with parts list and where to get any oddball parts.

A prototype had to be supplied too, so the mag's staff could see that it worked and take their own pics.

Enough info was needed for a hobbyist and others to build one and for parts dealers to make up kits. The cost of such had to be less than any similar commercial offering - a major hurdle.

One was forbidden to use exotic, hard to get parts or expect builders to own more than a DMM.

The article had to interesting reading in it own right, to help sell the magazine when sitting on seller stands.

I seriously doubt any the Three Stooges would have a clue how to do the same.

Win and Phil both author books (everybody should have both) and do
proprietary designs that they can't publish. Which means that they
work about 4x as hard as I do.

I design circuits on paper (literally on D-size vellum) and people do
the schematic entry and PCB layout for me. Other people program uPs
and FPGAs per my requirements. Other people code Python test software.
Other people sell the stuff.

What I publish is the documentation that manufacturing needs to build
and test and calibrate many products long-term. That's very different
from a magazine article. [1]

Do you have Win's and Phil's books? Everyone here should read them
cover to cover, as much for little details here and there as for the
grand themes.

[1] I have never seen a book about how engineers should create
documentation for manufacturing and test. All the companies that I've
worked for or with seem to have their own standards, if they have
standards.



--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

On Mon, 21 Oct 2019 00:14:05 -0700 (PDT), Phil Allison
<pallison49@gmail.com> wrote:

Bill Sloman wrote:

-------------------

Nobody is going to treat Phil Allison as a beginner.


** Happens here daily by Win, John and Phil H.

The Three Stooges.

Well, play the circuit design game with us. It's fun.



--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

On Mon, 21 Oct 2019 07:57:11 -0000 (UTC), Steve Wilson <no@spam.com>
wrote:

jlarkin@highlandsniptechnology.com wrote:

The issue was series strings of electrolytic caps, where the total
supply voltage is more than the rated voltage of the caps. Film caps
can blow up in that situation. What do lytics do?

Answer: their IV curves make them safely self-equalize.

How does self-equalization work, and why does the I-V curve have to be
exponential?

The cap with more voltage across it would conduct way more current,
which would integrate to lower voltage on itself and more on others.
The end result is obviously equal currents, but *less* current than
there would be if the voltages were evenly distributed in the string.

I never said "exponential", which isn't a requirement. Any healthy
upward-bending curve would do.

I didn't curve-fit my data. Maybe you can do that for us.

I experimented with some polymer aluminum caps that seemed to be
purely ohmic, and died without warning at about 1.6x rated voltage.
Those would not be safe in a pure series string. I didn't use them in
production.





--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[John S]

On 10/21/2019 2:14 AM, Phil Allison wrote:

Bill Sloman wrote:

-------------------

Nobody is going to treat Phil Allison as a beginner.


** Happens here daily by Win, John and Phil H.

The Three Stooges.


He's not complaining about not having his hand held,
but rather the absence of proper documentation.

** Not complaining about anything like that.

Just the ingenuous nature of JLs malicious trap request.


He may be asking a bit much. Proper documentation is bulky.


** Have you *never* seen a published project in a magazine or on line ?

Ones I did for EA magazine consisted of 2 to 3 thousand words, colour pics, a PCB pattern and component layout, specifications list, block diagrams and of course a full schematic with parts list and where to get any oddball parts.

A prototype had to be supplied too, so the mag's staff could see that it worked and take their own pics.

Enough info was needed for a hobbyist and others to build one and for parts dealers to make up kits. The cost of such had to be less than any similar commercial offering - a major hurdle.

One was forbidden to use exotic, hard to get parts or expect builders to own more than a DMM.

The article had to interesting reading in it own right, to help sell the magazine when sitting on seller stands.

I seriously doubt any the Three Stooges would have a clue how to do the same.



.... Phil

And I doubt you would have a clue how to write a book similar to "The
Art of Electronics" as has been done by one of the Three Stooges.

If you don't like this group, go find another. Otherwise, shut up.

 

[Winfield Hill]

jlarkin@highlandsniptechnology.com wrote...

On 21 Oct 2019, Winfield Hill wrote:
Phil Allison wrote...

You can make a 100nF Green Cap smoke and explode with a
40W bench amplifier and a series inductor of a few mH
operating at resonance.

Good cheap fun.

The caps can easily have Q in excess of 1000. I have
made inductors with Q that high, with litz wire, etc.,
but most are much lower. But even Q=100 can potentially
turn 35 volts into over 3.5 kV. However, high Zout of
the amplifier is a severe Q limitation.

Zout doesn't matter. Q doesn't matter. All you need is current.

The series inductor Q will be determined by its esr
in series with the amplifier's Zout. A high Q leads
to high resonant recirculating currents. Most amps
have low Zout, but 70-volt PA outputs are often not.


--
Thanks,
- Win

 

[John Larkin]

On Sat, 19 Oct 2019 20:34:45 -0700 (PDT), Phil Allison
<pallison49@gmail.com> wrote:

jla...@highlandsniptechnology.com wrote:

-----------------------------------------



** Test 'em to destruction I say ...

Just kidding, but current limited breakdown testing is simply the only way to do find out the actual limit of many parts. Carried out sensibly, it does no damage.


Unless a part is very expensive, may as well test it to destruction.

With some parts, the first indication of impending breakdown is
failure.

https://www.dropbox.com/s/4nxm7m2q3j3buvc/ExFets.jpg?dl=0

https://www.dropbox.com/s/gpc169hj1ilp6xa/photo01x_exploded_resistors.jpg?dl=0



** I have a TO3 lateral MOSFET with a neat, round hole in the top of the lid.

Not the only example I have seen.

Just below the hole is the top of the drain pin, somewhat burnt.




..... Phil

The springy source wire bond strap would sometimes fly off the chip
and hit the top of the can. Bipolars did that too.

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[John Larkin]

On Sat, 19 Oct 2019 19:55:00 -0700 (PDT), Phil Allison
<pallison49@gmail.com> wrote:

George Herold wrote:

---------------------

Anecdote:

I once purchased a quantity of MJ15030/31s from a popular components retailer in Sydney. These are medium power TO220 pak devices rated at 160V for use as output drivers in power amplifiers.

Nearly all of them were *dead short* as purchased !!

I got a very grumpy reaction when I returned them and refused to take more from the same bin. WTF - Motorola do not supply dead BJTs.

I smelt a rat, someone had been at them before me.

Turned out a local amplifier maker ( Chris from PTM Electronics ) "borrowed" hundreds of them from the same store to put through his quality checking process then returned any he did not like.

His "process" involved the use of an old HP Curve Tracer, which is well capable of destroying such devices and had done so to a great many.

Wot an asshole.


Huh, I mostly buy from digikey, (newark/mouser/..)


** This was quite a while ago, about 1985.

Companies like Farnell / Newark etc had not set up business in Australia then and getting trustworthy semis in small quantities was a regular hassle.

Besides the damaged MJs, I got any number of Motorola fakes from well known outlets about that same time - mostly MJ15003/4 types from Dick Smith Electronics, remember the Aussie helicopter aviator ?

Dick Smith invented the Coa Thanger car antenna.

There was a Dick Smith retail store in Silicon Valley, but it didn't
last long. It had a lot of salesmen and cheap parts and no customers.

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[John Larkin]

On Mon, 21 Oct 2019 02:58:51 -0700 (PDT), Phil Allison
<pallison49@gmail.com> wrote:

Piotr Wyderski is Nuts wrote:

------------------------------



** Have you *never* seen a published project in a magazine or on line ?

I have several such projects in my portfolio, but all in Polish


** So not published by any leading national magazine.

Sadly, there are no decent electronics mags any more. It's pitiful.

I did get a mention and a page or two in AoE3, which is an honor to
me. I might show up in the x-files, too.

Generations of struggling EE students will have to see my diffamp and
exploded resistors. Thanks, Win.

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[John Larkin]

On 21 Oct 2019 09:03:23 -0700, Winfield Hill <winfieldhill@yahoo.com>
wrote:

jlarkin@highlandsniptechnology.com wrote...

On 21 Oct 2019, Winfield Hill wrote:
Phil Allison wrote...

You can make a 100nF Green Cap smoke and explode with a
40W bench amplifier and a series inductor of a few mH
operating at resonance.

Good cheap fun.

The caps can easily have Q in excess of 1000. I have
made inductors with Q that high, with litz wire, etc.,
but most are much lower. But even Q=100 can potentially
turn 35 volts into over 3.5 kV. However, high Zout of
the amplifier is a severe Q limitation.

Zout doesn't matter. Q doesn't matter. All you need is current.

The series inductor Q will be determined by its esr
in series with the amplifier's Zout. A high Q leads
to high resonant recirculating currents. Most amps
have low Zout, but 70-volt PA outputs are often not.

If you have a series resonant L-C, and there is X volts AC across its
terminals, it doesn't care what the generator source impedance is. The
voltage across the cap is the AC current times Xc.

I measure Q that way. Look at the input voltage of the LC, and the
voltage across the element, and divide. It can be a 0.1 ohm source but
more likely 50.

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com