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Old 12-31-2010, 10:19 AM   #21
Pyr0Beast
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Default Re: KZG - KZJ - Same Electrolyte

No it does not. Ripple voltage merely modulates DC. It flows in and out of cap. But never makes the cap reverse polarised.
It is voltage sag/rise on DC systems.

Stick a polarised lytic on AC and it will blow. But AC is not ripple.
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Old 12-31-2010, 12:40 PM   #22
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Default Re: KZG - KZJ - Same Electrolyte

Ripple is AC, it's just not line frequency or a clean sine wave.
- The cap blows by the exact same mechanism in which Ripple damages the Oxide layer.

What I'm saying needs no more proof than the existence of the term "Self Healing Capacitor", because if there were no damage done there would be nothing to heal and there would be no such term.

The are a number of manufactures with documents that discuss this in great detail.
- I suggest you try a little reading.
.
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Old 12-31-2010, 01:25 PM   #23
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Default Re: KZG - KZJ - Same Electrolyte

Quote:
Nope. Oxide layer does not dissolve that easily.
Old caps that have gathered dust for past 5 years, yes. They need to be regenerated.
Fascinating.
Quote:
That's why they recommend 're-forming' old caps before use.
So this really is a science in itself manufacturing these capacitors. These companies must have years and years of research based on data gathered from the field so-to-speak.

No wonder why the counterfeiters can't produce any decent products. Their manufacuring process relies on extrapolative data rather than interpolative.

Now, this re-forming you speak of.... Say I have old stock MBZ for example, from '00 or '01... How would you recommend I re-form it? Should I apply a small amount of DC current for an hour? Like a 1.5V battery?
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Old 12-31-2010, 03:49 PM   #24
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Default Re: KZG - KZJ - Same Electrolyte

Ripple is AC, it's just not line frequency or a clean sine wave.
Of course it is. But AC is not ripple.

AC swings from positive, crosses zero then into negative.
Ripple is modulated voltage atop DC. It should never go to zero - such device would immediately lock up.


What I'm saying needs no more proof than the existence of the term "Self Healing Capacitor", because if there were no damage done there would be nothing to heal and there would be no such term.

Tantalums are self healing as well. It means that any internal defects will not result in failure of the device like in some foil capacitors which will fail shorted.
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Old 12-31-2010, 04:31 PM   #25
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Default Re: KZG - KZJ - Same Electrolyte

Quote:
Originally Posted by Pyr0Beast View Post
Ripple is AC, it's just not line frequency or a clean sine wave.
Of course it is. But AC is not ripple.

AC swings from positive, crosses zero then into negative.
Ripple is modulated voltage atop DC. It should never go to zero - such device would immediately lock up.
Okay... You just need to study in general then..

Quote:
Originally Posted by Pyr0Beast View Post
Tantalums are self healing as well.
No kiddin?
There are several other kinds that are also self healing.
Can you list them too please while your at it?
None of them do it the way lytics do though.

Quote:
Originally Posted by Pyr0Beast View Post
It means that any internal defects will not result in failure of the device like in some foil capacitors which will fail shorted.
Yes that's what self healing does.
When you are done studying Tantalums go study some lytics that weren't made 40 years ago.
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Old 12-31-2010, 05:02 PM   #26
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Default Re: KZG - KZJ - Same Electrolyte

Okay... You just need to study in general then..
Or you should.

No kiddin?
There are several other kinds that are also self healing.
Can you list them too please while your at it?
None of them do it the way lytics do though.

Thin foil, oil filled with PP film, most of the X or Y type caps, some silver mica types and more.

Lytics leak lots of current to maintain their oxide layer and their form of healing can be burning off the material, same as with some tantalums and film capacitors.

Yes that's what self healing does.
When you are done studying Tantalums go study some lytics that weren't made 40 years ago.

Bah.


No wonder why the counterfeiters can't produce any decent products. Their manufacuring process relies on extrapolative data rather than interpolative.

There is no point in producing decent counterfeits.

Also if those cheap companies produced quality products they will go out of business due to designed for the dump economy.


Now, this re-forming you speak of.... Say I have old stock MBZ for example, from '00 or '01... How would you recommend I re-form it? Should I apply a small amount of DC current for an hour? Like a 1.5V battery?

Wire a 1kOhm resistor in series and apply half the rated voltage.
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Old 12-31-2010, 05:36 PM   #27
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Default Re: KZG - KZJ - Same Electrolyte

Quote:
Originally Posted by mockingbird View Post
Now, this re-forming you speak of.... Say I have old stock MBZ for example, from '00 or '01... How would you recommend I re-form it? Should I apply a small amount of DC current for an hour? Like a 1.5V battery?
There are as many different opinions on the specifics of how to do that as their are manufacturers.
The exact times and/or size of the voltage steps is where there is no agreement.

There are two favored methods.
#1 - Start them at with like 1-2 volts on them for a 10-15 minutes. - Then start raising voltage a volt or two at a time and let them sit at each step for 5 minutes. - Once you get to the rated voltage let them sit for 5 minutes x # of years stored. [7 years would be 35 minutes at the rated voltage. (Last step.)]
#2 The other method is put a resistor in series with the cap and apply rated voltage to them. [Resistor size varies between 1.5k and 50k depending on who you read from. - Most of them specify a 5 watt resistor so shoot for an ohms value that would keep the resistor below 5 watts at the caps rated voltage if there was no cap in the circuit.] - When you first start the cap will be leaky and current will flow but the resistor will limit it so the cap doesn't get damaged. As the oxide layer builds leakage will go down. As leakage nears zero the voltage drop on the cap will get near the rated voltage [cap is almost an open to DC now] and the voltage dropped across the resistor will approach zero. [One says] if the voltage on the *resistor doesn't go below 10% of the applied (cap's rated) voltage within an hour the cap is crap and to toss it. If it does get to 10% in less than an hour then leave it sit for another hour [to build more oxide film] before calling it good.
.

According to Sprague's 1990 electrolytic capacitor catalog.
"""When aluminum electrolytic capacitors were first developed deterioration on-the-shelf was a major problem and frequent replacement of stock parts was necessary. Additionally, use of capacitors for extended periods at small percentages of rated voltage permitted the dielectric oxide film to deform, just as it would on-the-shelf. Both problems were solved in the early 1950's with the introduction of high-purity aluminum foil. Oxide film stability was greatly enhanced and today aluminum electrolytics can be used after storage, and at any percentage of rated voltage, without loss of capacitor quality."""

- The 1950's is when Lytics became self-healing but no one sent Pyr0Beast the memo.

I also read something from back then [before the early 50's] that said stored lytic caps needed to be reformed after 6 months.
- Glad it's not like that anymore!
.

Last edited by PCBONEZ; 12-31-2010 at 05:45 PM..
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Old 12-31-2010, 05:40 PM   #28
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Default Re: KZG - KZJ - Same Electrolyte

Quote:
Originally Posted by Pyr0Beast View Post
Lytics leak lots of current to maintain their oxide layer and their form of healing can be burning off the material, same as with some tantalums and film capacitors.
Nope that's not how it works with Aluminum Lytics.
Aluminum Lytics patch the weak spot in the dielectric by replacing the oxide layer.
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Old 12-31-2010, 05:41 PM   #29
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Default Re: KZG - KZJ - Same Electrolyte

The 1950's is when Lytics became self-healing but no one sent Pyr0Beast the memo.
Oh really. Where did I say they didn't ?
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Old 12-31-2010, 05:55 PM   #30
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Default Re: KZG - KZJ - Same Electrolyte

Quote:
Originally Posted by PCBONEZ View Post
Nope that's not how it works with Aluminum Lytics.
Aluminum Lytics patch the weak spot in the dielectric by replacing the oxide layer.
.
That is another way of self healing.
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Old 12-31-2010, 06:36 PM   #31
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Default Re: KZG - KZJ - Same Electrolyte

That's progress, back to this.

Quote:
Originally Posted by Pyr0Beast View Post
AC swings from positive, crosses zero then into negative.
As does Ripple.
Because Ripple is an -ALTERNATING- current. [aka AC]

Quote:
Originally Posted by Pyr0Beast View Post
Ripple is modulated voltage atop DC. It should never go to zero - such device would immediately lock up.
Wrong.
The Ripple's [aka AC's] reference voltage is the DC voltage.
To it the DC voltage -IS- zero.
- Unlike the DC voltage, the Ripple [aka AC] produces an actual current through the cap which is always ALTERNATING in direction.

When that current is going the wrong direction, the Oxide layer is on the wrong side of the Aluminum to block it so the electrons leave the plate and punch into the oxide on the Aluminum side.
Occasionally [some percentage of the time] those trons physically blow a chuck of oxide [a few molecules] out of the Oxide layer.
Those chunks get [temporarily] entangled in the paper and electrolyte chemicals and thus do not return to the hole when the AC reverses.
[That's how ripple causes damage.]
The chunk then dissolves in the electrolyte but that takes some time so those particular molecules aren't available for now.
Meanwhile, previously dissolved chunks and appropriate [same chemical as the chunks] constituents of the electrolyte are drawn into the hole by the applied DC voltage [as the molecules have a charge] and a chemical reaction occurs. A different 'set' of oxide molecules forms in the hole restoring the layer.
[That's the healing.]

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Old 12-31-2010, 06:38 PM   #32
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Default Re: KZG - KZJ - Same Electrolyte

To dissolve oxide layer, electrolytic cap would need to be discharged and then reverse polarised. If it has DC on it it that is greater than ripple voltage that cannot be true.
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Old 12-31-2010, 06:40 PM   #33
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Default Re: KZG - KZJ - Same Electrolyte

Hogwash

The oxide layer dissolves in storage with no voltage applied at all.
That's why caps have to be reformed.

It's a chemical reaction.
Electricity has nothing to do with it other than positioning the molecules to encourage the reaction.

.

Last edited by PCBONEZ; 12-31-2010 at 06:45 PM..
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Old 12-31-2010, 06:42 PM   #34
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Default Re: KZG - KZJ - Same Electrolyte

Ripple current
In most applications, an a.c. or ripple voltage exists on top of a d.c. voltage and causes a ripple current and a self-heating of the elcap.
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Old 12-31-2010, 06:51 PM   #35
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Default Re: KZG - KZJ - Same Electrolyte

Yes, the AC CURRENT causes heat.
Without CURRENT, you won't get heat.

The AC CURRENT is those moving trons that sometimes blast chunks out of the layer.
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Old 12-31-2010, 06:54 PM   #36
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Default Re: KZG - KZJ - Same Electrolyte

Those chunks will only get blasted off when plate goes negative. If you leave cap at 0V it won't go anywhere.
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Old 12-31-2010, 06:59 PM   #37
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Default Re: KZG - KZJ - Same Electrolyte

Yes if both AC and DC are at zero then it doesn't blow chucks,
- the layer just dissolves slowly back into the electrolyte solution,
- it dissolves the same way as the chucks that get blown into the electrolyte when there is AC voltage.

We are talking about blowing chunks and I haven't even been drinking.
.

Last edited by PCBONEZ; 12-31-2010 at 07:02 PM..
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Old 12-31-2010, 07:00 PM   #38
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Default Re: KZG - KZJ - Same Electrolyte

And if AC Peak-Peak is always lower than DC ?

Cap never goes reverse biased
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Old 12-31-2010, 07:11 PM   #39
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Default Re: KZG - KZJ - Same Electrolyte

Yes it does to AC.

You are trying to reference the AC [which has a current] to the DC [which doesn't have current] ground.
-- IOW: You are referencing the AC to the DC's ground.
That is an error.
Doesn't work that way.
.

What is the DC -current- through a charged cap?
--> 0

What is the AC Ripple -current- through the cap?
+ then - then + then - then + then -

What is the total current through the cap?
+ then - then + then - then + then -

.
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Old 12-31-2010, 08:00 PM   #40
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Default Re: KZG - KZJ - Same Electrolyte

What is the DC -current- through a charged cap?
--> 0


And some leakage yes.



What is the total current through the cap?
+ then - then + then - then + then -


What is total voltage on the cap?

+ then + then + then + then + then +
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