Holy Moly -- Residual Electricity????

In sci.physics krw wrote:
In article ,
says...
In sci.physics ChairmanOfTheBored wrote:
On Sun, 18 Nov 2007 06:35:02 GMT, wrote:

In sci.physics GoldIntermetallicEmbrittlement g wrote:
On Sat, 17 Nov 2007 21:45:02 GMT, wrote:

In sci.physics GoldIntermetallicEmbrittlement g wrote:
On Sat, 17 Nov 2007 09:59:55 -0800 (PST), Saucerhunter
wrote:

On Nov 6, 10:14 am, "Unknown" wrote:
No he's not. Capacitors do NOT smooth current. They reduce or eliminate
voltage fluctuations.nottooo..

Holy pulse capacitors. Batman!! Wanna try blowing something to hell??
Or maybe a good Marx generator will do.

Or a huge, charged pulse cap.


Wouldn't "reducing voltage fluctuations" also cause the current to be
"smoothed" as well? Simple Ohm's law would say yes. If voltage peaks or
"fluctuations" are reduced, then so too would be the instantaneous
currents associated with the circuit that said "reduced fluctuation"
voltages are passing though.

Yes, but you are confusing cause and effect.


Absolutely not. The term "smoothing cap" is valid, and has been in use
in the power supply industry for decades. The ****ing "effect" doesn't
matter. Both voltage ripple as well as current ripple is reduced.

The whole point of capacitors on a voltage source is to keep the
voltage constant, effectively lowering the power source internal
resistance, under a changing load, which means the current changes
with the load; it isn't "smoothed".

What exactly do you call "keep the voltage constant", other than
"smoothing"?

Regulation, which is something different.

The big capacitors in a power supply remove the ripple component by
virtue of forming a simple RC low pass filters.

Before most of the people here were born, the output section of a DC
power supply was invariably a Pi filter with two shunt "condensors"
and a series inductor.

With the availability of cheap, high value capacitors, the Pi section
and heavy, expensive inductor were replaced with one big ass capacitor
and people stopped going through the calculations to come up with the
optimal Pi section at the least cost.

You haven't a clue what you are talking about.


The current signatures of many of my power supply designs state that
you are incorrect.

If you spend years characterizing power supplies, you understand.

I retired from designing and characterizing power supplies years ago.

Perhaps you were too quick in forgetting what you did?

Not likely, DC power supply design is trivial for the most part.

The only non-trivial one I was involved with was a 3 phase switcher
that put out 35 volts with a 100 amp pulse load with millvolts ripple
and the only non-trivial problem with that was reliable start up sequencing.

Perhaps you haven't, and hence, you don't.

Perhaps you are just a foul mouthed snot.

Well, now there you got me.

Indeed.

--
Jim Pennino

Remove .spam.sux to reply.

In sci.physics ChairmanOfTheBored wrote:
On Mon, 19 Nov 2007 02:45:02 GMT, wrote:

Not likely, DC power supply design is trivial for the most part.


No. YOU are trivial, bitch.

Yet another foul mouthed little snot...

--
Jim Pennino

Remove .spam.sux to reply.

"Androcles" wrote in message
. uk...

"RnR" wrote in message
...
: On Fri, 16 Nov 2007 12:32:50 -0000, "M.I.5¾"
: wrote:
:
:
: "Androcles" wrote in message
: . co.uk...
:
: "M.I.5¾" wrote in message
: ...
: :
: : "Androcles" wrote in message
: : k...
: :
: : "M.I.5¾" wrote in message
: : ...
: : :
: : : "Randy Poe" wrote in message
: : : ups.com...
: : : On Nov 14, 10:52 am, "Unknown" wrote:
: : : How do you dream up all these ridiculous things?"M.I.5¾"
: : : wrote in message
: : :
: : : ...
: : :
: : :
: : :
: : : "Unknown" wrote in message
: : : .net...
: : : What type of capacitor has to cool off before it accepts a
: charge?
: : :
: : : A: A faulty one.
: : :
: : : It is well a known problem particularly among certain types
of
: : : electrolytic capacitors. The usual problem is that the EPR
: : (Effective
: : : parallel resistance) of the capacitor falls alarmingly as
it
: warms
: : up
: : : rendering it ineffective as a capacitor.
: : :
: : : Two charts of electrolytic capacitor failure modes. Check out
: : : Table 2 he
: : :
http://industrial.panasonic.com/www-...ABA0000TE4.pdf
: : :
: : : Operating at high temperature is shown to cause failure
: : : by increase in leakage current.
: : :
: : : or Figure 2.10 he
: : :
: :
:
http://etd.gatech.edu/theses/availab...200705_phd.pdf
: : :
: : : Operating at high temperature is shown to cause failure
: : : by loss of effective resistance (i.e. increased leakage).
: : :
: : : -----------
: : :
: : : Indeed. In general electrolytic capacitors are rated at either
85°C
: or
: : : 105°C. The former is obviously cheaper than the latter and
that's
: often
: : : what gets used as such supplies don't run that warm. However,
even
: if
: : : operated below 85°C, the former type are considerably more
: unreliable
: : than
: : : the latter.
: :
: : Oh, so the latter break down at temperatures below 85°C because
: : they are less reliable than the former cheaper ones... very
logical.
: :
: :
: : How you managed to arrive at that conclusion is anyone's guess.
:
: It's quite simple. Here's a table, you like tables.
:
: ------------------- Former ------------------
Latter ----------------
: 85°C reliable unreliable
: 85°C unreliable reliable
: _____________________________________________
:
:
: Don't be pillock all your life, have a day off occasionally. I neither
said
: that nor inferred it. I stated that even when operated below 85°C,
: capacitors rated at 85°C are more unreliable than those rated at 105°C.
:
:
:
: With all due respect, are we on a crusade to prove who is right or to
: help the now confused OP ?? Do you think the OP gave up on us? I
: know at this point if I were him, I would have.

If the OP doesn't have his answer by now he's in serious trouble.
This M.I.5¾ character seems to hallucinate that reliability is
a function of temperature without testing for failure rates
of 105°C rated capacitors at sub-zero temperatures, which
is the case for some military aircraft.


Thus proving beyond all reasonable doubt that you are imagining content in
my posts that simply isn't there.

I think the kill file beckons. Ah 'tis done.

"M.I.5¾" wrote in message
...
:
: "Androcles" wrote in message
: . uk...
:
: "RnR" wrote in message
: ...
: : On Fri, 16 Nov 2007 12:32:50 -0000, "M.I.5¾"
: : wrote:
: :
: :
: : "Androcles" wrote in message
: : . co.uk...
: :
: : "M.I.5¾" wrote in message
: : ...
: : :
: : : "Androcles" wrote in message
: : : k...
: : :
: : : "M.I.5¾" wrote in message
: : : ...
: : : :
: : : : "Randy Poe" wrote in message
: : : : ups.com...
: : : : On Nov 14, 10:52 am, "Unknown" wrote:
: : : : How do you dream up all these ridiculous things?"M.I.5¾"
: : : : wrote in message
: : : :
: : : : ...
: : : :
: : : :
: : : :
: : : : "Unknown" wrote in message
: : : : .net...
: : : : What type of capacitor has to cool off before it accepts
a
: : charge?
: : : :
: : : : A: A faulty one.
: : : :
: : : : It is well a known problem particularly among certain
types
: of
: : : : electrolytic capacitors. The usual problem is that the
EPR
: : : (Effective
: : : : parallel resistance) of the capacitor falls alarmingly as
: it
: : warms
: : : up
: : : : rendering it ineffective as a capacitor.
: : : :
: : : : Two charts of electrolytic capacitor failure modes. Check out
: : : : Table 2 he
: : : :
: http://industrial.panasonic.com/www-...ABA0000TE4.pdf
: : : :
: : : : Operating at high temperature is shown to cause failure
: : : : by increase in leakage current.
: : : :
: : : : or Figure 2.10 he
: : : :
: : :
: :
:
http://etd.gatech.edu/theses/availab...200705_phd.pdf
: : : :
: : : : Operating at high temperature is shown to cause failure
: : : : by loss of effective resistance (i.e. increased leakage).
: : : :
: : : : -----------
: : : :
: : : : Indeed. In general electrolytic capacitors are rated at
either
: 85°C
: : or
: : : : 105°C. The former is obviously cheaper than the latter and
: that's
: : often
: : : : what gets used as such supplies don't run that warm.
However,
: even
: : if
: : : : operated below 85°C, the former type are considerably more
: : unreliable
: : : than
: : : : the latter.
: : :
: : : Oh, so the latter break down at temperatures below 85°C because
: : : they are less reliable than the former cheaper ones... very
: logical.
: : :
: : :
: : : How you managed to arrive at that conclusion is anyone's guess.
: :
: : It's quite simple. Here's a table, you like tables.
: :
: : ------------------- Former ------------------
: Latter ----------------
: : 85°C reliable unreliable
: : 85°C unreliable reliable
: : _____________________________________________
: :
: :
: : Don't be pillock all your life, have a day off occasionally. I
neither
: said
: : that nor inferred it. I stated that even when operated below 85°C,
: : capacitors rated at 85°C are more unreliable than those rated at
105°C.
: :
: :
: :
: : With all due respect, are we on a crusade to prove who is right or to
: : help the now confused OP ?? Do you think the OP gave up on us? I
: : know at this point if I were him, I would have.
:
: If the OP doesn't have his answer by now he's in serious trouble.
: This M.I.5¾ character seems to hallucinate that reliability is
: a function of temperature without testing for failure rates
: of 105°C rated capacitors at sub-zero temperatures, which
: is the case for some military aircraft.
:
:
: Thus proving beyond all reasonable doubt that you are imagining content in
: my posts that simply isn't there.
:
: I think the kill file beckons. Ah 'tis done.

Always nice to see a chicken **** duck out without proving his claim.

"However, even if operated below 85°C, the former type are considerably more
unreliable than the latter." - Chicken **** "MI5" and a bit.

In article ,
says...
In sci.physics krw wrote:
In article ,
says...
In sci.physics ChairmanOfTheBored wrote:
On Sun, 18 Nov 2007 06:35:02 GMT, wrote:

In sci.physics GoldIntermetallicEmbrittlement g wrote:
On Sat, 17 Nov 2007 21:45:02 GMT, wrote:

In sci.physics GoldIntermetallicEmbrittlement g wrote:
On Sat, 17 Nov 2007 09:59:55 -0800 (PST), Saucerhunter
wrote:

On Nov 6, 10:14 am, "Unknown" wrote:
No he's not. Capacitors do NOT smooth current. They reduce or eliminate
voltage fluctuations.nottooo..

Holy pulse capacitors. Batman!! Wanna try blowing something to hell??
Or maybe a good Marx generator will do.

Or a huge, charged pulse cap.


Wouldn't "reducing voltage fluctuations" also cause the current to be
"smoothed" as well? Simple Ohm's law would say yes. If voltage peaks or
"fluctuations" are reduced, then so too would be the instantaneous
currents associated with the circuit that said "reduced fluctuation"
voltages are passing though.

Yes, but you are confusing cause and effect.


Absolutely not. The term "smoothing cap" is valid, and has been in use
in the power supply industry for decades. The ****ing "effect" doesn't
matter. Both voltage ripple as well as current ripple is reduced.

The whole point of capacitors on a voltage source is to keep the
voltage constant, effectively lowering the power source internal
resistance, under a changing load, which means the current changes
with the load; it isn't "smoothed".

What exactly do you call "keep the voltage constant", other than
"smoothing"?

Regulation, which is something different.

I'll agree that regulation is somewhat different, but this isn't
regulation.

The big capacitors in a power supply remove the ripple component by
virtue of forming a simple RC low pass filters.

....smoothing the voltage waveform.

Before most of the people here were born,

I highly doubt it.

the output section of a DC
power supply was invariably a Pi filter with two shunt "condensors"
and a series inductor.

DIfferent requirements = different filters. In case you hadn't
noticed, there aren't many tubes being used anymore either.

With the availability of cheap, high value capacitors, the Pi section
and heavy, expensive inductor were replaced with one big ass capacitor
and people stopped going through the calculations to come up with the
optimal Pi section at the least cost.

...and your point is? It's really just a different calculation.

You haven't a clue what you are talking about.


The current signatures of many of my power supply designs state that
you are incorrect.

If you spend years characterizing power supplies, you understand.

I retired from designing and characterizing power supplies years ago.

Perhaps you were too quick in forgetting what you did?

Not likely, DC power supply design is trivial for the most part.

Perhaps your designs were trivial, however not all are.

The only non-trivial one I was involved with was a 3 phase switcher
that put out 35 volts with a 100 amp pulse load with millvolts ripple
and the only non-trivial problem with that was reliable start up sequencing.

Try a multi-kA +1.25V/-3V three-phase phase-controlled regulator if
you want start-up problems. ...but I still don't know what this has
to do with the topic at hand,

Perhaps you haven't, and hence, you don't.

Perhaps you are just a foul mouthed snot.

Well, now there you got me.

Indeed.



--
Keith