KZG - KZJ - Same Electrolyte

[PCBONEZ]

Re: KZG - KZJ - Same Electrolyte

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.
.

[PCBONEZ]

Re: KZG - KZJ - Same Electrolyte

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!
.

[Pyr0Beast]

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.

[PCBONEZ]

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.

Okay... You just need to study in general then..

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.

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.
.

[Pyr0Beast]

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.

[mockingbird]

Re: KZG - KZJ - Same Electrolyte

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.

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?

[PCBONEZ]

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.
.

[Pyr0Beast]

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.

[PCBONEZ]

Re: KZG - KZJ - Same Electrolyte

I doubt that ripple would eat oxide layer. That wouldn't happen as long as cap doesn't go into reverse polarity.

Ripple DOES go in reverse polarity.
It is a small AC ridding on a DC.
.
If you think it won't eat the layer stick a DC [polarized] cap on AC with no DC and tell me what happens.
.

[Pyr0Beast]

Re: KZG - KZJ - Same Electrolyte

I doubt that ripple would eat oxide layer. That wouldn't happen as long as cap doesn't go into reverse polarity.

[PCBONEZ]

Re: KZG - KZJ - Same Electrolyte

Yeah,,, what he said...

[PCBONEZ]

Re: KZG - KZJ - Same Electrolyte

... You said that the electrolyte oxidizes the aluminium when DC voltage is applied, and when it ceases, it "self heals". Surely this process would take a minute or two, so when the current is initially applied, the capacitance would be significantly out of spec?

No, misinterpretation,,,

Ripple damages the -existing- oxide layer and the DC repairs the damage.
- Bear in mind the ripple is in mV and the DC is in Volts. Small local damaged areas, big global [so to speak] healing.
- Also once the oxide layer gets to a certain thickness [based on the applied DC] the healing will stop because the oxide layer is an insulator.
- Also a thin area [damaged] of the oxide layer will get the most healing effect simply because the insulation is thinner there.

The aluminum foil is etched and pre-oxidized to some extent [usually chemically] before the foil pack is rolled.
Then they use a process called 'forming' to build up the oxide layer.
Forming is basically applying DC at a low voltage then slowing increasing it to build up the oxide layer's thickness to what it should be for the rated voltage.

In other words caps come from the factory with an oxide layer.

The oxide layer doesn get thinner with no DC applied but it takes years.
-The oxide dissolving back into the electrolyte on unused caps is one major things [if not THE major thing] that determines shelf-life.
That's why they recommend 're-forming' old caps before use.
.

[Pyr0Beast]

Re: KZG - KZJ - Same Electrolyte

Nope. Oxide layer does not dissolve that easily.

Old caps that have gathered dust for past 5 years, yes. They need to be regenerated.

[mockingbird]

Re: KZG - KZJ - Same Electrolyte

... You said that the electrolyte oxidizes the aluminium when DC voltage is applied, and when it ceases, it "self heals". Surely this process would take a minute or two, so when the current is initially applied, the capacitance would be significantly out of spec?

[PCBONEZ]

Re: KZG - KZJ - Same Electrolyte

You lost me.. ??

""instantaneously provide their rating"" ??

What which rating??

[mockingbird]

Re: KZG - KZJ - Same Electrolyte

Interesting. But if this is the case, why do capacitors instantaneously provide their rating, if it took voltage to "stimulate" them, wouldn't you have to wait a minute or two for the voltage to do it's work?

[PCBONEZ]

Re: KZG - KZJ - Same Electrolyte

In Aluminum Electrolytics the Aluminum Oxide layer -IS- the Dielectric.
The separator paper is only in there to act as a carrier [flow path sort'a] so the electrolyte can get to the Aluminum to keep it oxidized.

Ripple currents blast chunks [figuratively] of the Oxide [or Aluminum depending on instantaneous polarity] into solution where it disolves.
The DC voltage present restores the damaged areas similar to how electroplating works.
- That's why electrolytics used to be called 'self healing capacitors', although the term has fallen out of use over the years.
.

[Pyr0Beast]

Re: KZG - KZJ - Same Electrolyte

You have silver mica capacitors.

But ordinary lytics need to oxidise to work properly. Aluminium oxide works as an insulator.

[mockingbird]

Re: KZG - KZJ - Same Electrolyte

I wonder how gold would factor in with capacitor electrolyte. Is it possible to create really high quality stuff with it? It is a highly conductive metal and it doesn't oxidize, unless you throw it in highly concentrated sulphuric acid.

[PCBONEZ]

Re: KZG - KZJ - Same Electrolyte

It's some kind of Aluminum solution because the foil it is 'electrolyticing' with is Aluminum.

I think they made a bad choice in one of their stabilizer additives and the electrolyte simply breaks down.

.