Film capacitor as power-supply filter

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
 Click to see the full signature
Reply to
jlarkin
Loading thread data ...

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?

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
 Click to see the full signature
Reply to
jlarkin

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

--
John Larkin         Highland Technology, Inc 

lunatic fringe electronics
 Click to see the full signature
Reply to
jlarkin

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.

Reply to
John S

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
Reply to
Winfield Hill

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
 Click to see the full signature
Reply to
jlarkin

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  
 Click to see the full signature
Reply to
John Larkin

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  
 Click to see the full signature
Reply to
John Larkin

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  
 Click to see the full signature
Reply to
John Larkin

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  
 Click to see the full signature
Reply to
John Larkin

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

** My inductor was large, air cored, 5.6mH and with 0.8ohms series R.

To ensuequick death needs about 250VAC at resonance = 7.7 kHz.

** Ordinary SS power amp with output Z of about 0.25 ohms.
** Think you are over thinking this.
** I was just having innocent fun destroying Greencaps and a number of X2 rated polyester mains caps. 3kV ceramics stood up quite well.

Needed to knew the limits cos of the high AC voltages on the primary side of valve output transformers.

Can reach 5kV rel to chassis under certain conditions.

But audio just simple shit.

.... Phil

Reply to
Phil Allison

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

** JL has still missed the point of my juxtaposition.

Maybe it was too pointed ....

( snip pile of worthless JL drivel and trumpet blowing )

FYI to all:

Fraid I am not one bit interested in ANY of JLs nonsense replies to my serious complaints.

There are none so blind as those who will not see.

Then there are people like JL.

..... Phil

Reply to
Phil Allison

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

** Not true at all.

Was already invented and named by radio hams ( we call them "amateurs" ) before Dick mentioned them in one of his catalogues. The correct name is "co-tanger", a pun on "co-linear".

** Be like selling ice blocks to Eskimos.

..... Phil

Reply to
Phil Allison

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

** Really?

Hitachi TO3 lateral mosfets have thin, aluminium drain wires that act as fuses under chip failure conditions.

The resulting metal vapour can initiate an arc from drain pin to the lid above that continues, backed up by a hefty 110VDC supply.

A neat, round hole forms and enlarges to a few mm diameter before self extinguishing.

The cute things is the amplfifer normally keeps going afterwards with the remaining good mosfets.

Audio is simple shit.

..... Phil

Reply to
Phil Allison

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

** Blah, blah, blah,

JL has no idea he is posting worthless responses.

Concertos for solo trumpet, his own and now others.

I already 100% KNOW how The Three Stooges behave here

= appallingly !!!

Not one word of JL's narcissistic drivel can undo that.

..... Phil

Reply to
Phil Allison

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

** Ummmm - where did the 70V PA amp come from ??

I know my initials are "PA" but that cannot be it.

Three Stooges logic ?

Make any mad assumption you feel like and post it as fact ?

FYI to all:

the good thing about writing text books is that you do not have to put up with being contradicted or having your mistakes pointed out in real time.

In fact, you can pretty much get away with murder.

At Sydney Uni in the early 70s, we used the still popular text

"Fundamentals of Physics " by US team Halliday and Resnick.

It was chock full of mistakes, particularly in the test questions.

About 50% of the published answers were wrong - the smarter students ( 18 year olds) were able to point out the exact logical & math errors that had led to the wrong answers.

Of course, this paled into insignificance in comparison to the absurd level of mistakes found in notes and black board math supplied by lecturers - most of them PhD students.

No complaints from undergrad students were possible nor errors ever corrected.

And I was doing the special " Honours Physics " course.

Not very honourable.

.... Phil

Reply to
Phil Allison

Yeah, but... real HV capacitors need a shorting chain EVERY time. An uplugged genset can resonate with wall wiring, and melted shorting chain is the best way to find out about that sort of thing...

Reply to
whit3rd

Please post those links to stuff you have designed and I (apparently) snipped.

--
John Larkin         Highland Technology, Inc 

lunatic fringe electronics
 Click to see the full signature
Reply to
jlarkin

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

** Needs no more PCB space than pair of 47uF, 450V electros.

Cheaper as well.

.... Phil

Reply to
Phil Allison

Which is to say, they aren't designs.

Egomaniacs like John Larkin don't make good brainstormers - they tend to ho g the discussion. They don't notice that they are doing this.

What I've seen hasn't been impressive, and most of it had been around for s o long that it didn't actually count as helpful.

Egomaniacs don't tend to notice other peoples contributions.

They are circuit diagrams, and - as such - can incorporate elements that il lustrate how a particular design could work.

The map is not the territory, but Spice simulations - in expert hands - can illustrate the territory in some detail.

Parasitic elements - lead inductances, stray capacitances, interwinding cap acitances in transformers - do need to be kept in mind, even if they can of ten be ignored.

But can make it difficult to extract the big picture.

fact NOT mine was absurd. I shot it to pieces and so he ignored me.

What's that got to do with anything?

Some people are very complacent. It can take a certain amount of verbal vio lence to get them to register that they are being disagreed with.

John Larkin expects a non-stop stream of praise, and fells insulted if he d oesn't get it.

Engineering is about understanding what you put together. You have just con fessed to being a tinkerer.

rs and crucial - cos it may be very good or very bad. A simple fact JLs ra ging ASD and pig arrogance prevents him from knowing.

Instincts are preprogrammed by evolution. Transistors haven't been around f or long enough for this to work.

Quite a lot of human cognition occurs in the sub-conscious. Anybody who has woken up with the realisation that a particular circuit won't work will be aware of that.

The fact that you weren't conscious of the processing going on doesn't make it instinctive.

Once you have worked out that something isn't going to work you have an obl igation to work out why it isn't going to work, so that you can explain it to other people.

Twaddle. Or - to be more specific - one of Roger Penrose's less plausible s peculations.

It annoys even more people who don't like gratuitous and unhelpful nonsense .

It undercuts your favourite sort of pretentious drivel.

Mostly it doesn't have to be explained in detail, but not every picture is worth a thousand words, and some written text can save a lot of barking up the wrong tree.

If only he knew enough to realise what he was apologising for.

There's a least one paper on man-machine interaction that spells out the wa y engineers aren't conscious of what they are doing.

The prize example was an instrument designed by a left-handed engineer that right-handers found very difficult to use. For some reason, left-handers - like me - are less inconvenienced by the choices that right-handers make ( probably because being right-handed seems to be frequently a consequence of brain-editing that doesn't seem to happen in left-handers, who are essenti ally the half of the ambidextrous population who got into the habit of usin g their left hand more often).

The more substantial comment was about error-recovery - engineers knew what the machine was doing, and knew how to get it to recover after they had do ne something wrong.

Naive users had a harder time because the engineers didn't write the error recovery procedures into the manual - they didn't realise that they had to spell them out.

--
Bill Sloman, Sydney
Reply to
Bill Sloman

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.