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Re: NCC KZGs really that bad?
ESR = Equivalent Series Resistance
It's basically the 'resistance' to Ripple passing through the cap.
The units are Ohms.
Since a filter cap's job is to get rid of Ripple by providing a path to ground, the smaller the ESR is, the less 'resistance' there is to the Ripple going through it to ground.
Caps like KMG are used in circuits where the Ripple has already been removed or is small or for signal coupling.
The 'Ripple' we talk about as a cap's rating is basically how much Ripple Current it [the cap] can pass without overheating internally.
Ripple Current [the rating] is to a cap as a watts rating is to a resistor.
Keep in mind Ripple is AC noise.
The DC obviously doesn't go through the cap.
Since it is AC 'resistance' isn't the correct word so they call it 'Equivalent', as in equivalent ohms to having a resistor in series with an 'ideal' cap. [Which would have zero ESR.]
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Re: NCC KZGs really that bad?
Why is there ripple after the AC has been converted to DC? I thought the components which converted it cut of the high and low waves, so shouldn't there be a steady stable line of DC?Comment
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Re: NCC KZGs really that bad?
The ripple is from the switchers switching in SMPS.
The PSU is a SMPS.
The VRM is a SMPS.
There are single chip SMPS all over a motherboard.
- But they often call them voltage regulators or converters.
On a basic level a single MOSFET regulator is still a SMPS.
.
When the switchers switch they create little voltage spikes. [Ripple.]
That's also why the Ripple frequency is near 100 kHz instead of 50 or 60 Hz.
.Mann-Made Global Warming.
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Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.
- Dr Seuss
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You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
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Re: NCC KZGs really that bad?
And for the new guy...
"Switchers" = Switching Transistors.
On a mobo they are usually MOSFETs.Mann-Made Global Warming.
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Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.
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You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
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Re: NCC KZGs really that bad?
If you mean in the primary, there's actually a HUGE amount of ripple there. It's the ability of a regulated switchmode supply to compensate for low frequency ripple that allows for rather small primary capacitors. It's simple - diodes take the AC which goes +/- and turn it into DC which only goes from ground to one polarity (positive, or negative). But now this voltage has the shape of a half sine, there are still peaks and throughs (zeros actually). So you need the capacitor to turn that into "usable" DC, something resembling more a steady line.
If you had a capacitor with infinite capacitance and zero ESR, there would be no ripple. But it would also need an infinite amount of time OR an infinite amount of current to charge it in the first place.
A working TV? How boring!Originally posted by PeteS in CAComment
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Re: NCC KZGs really that bad?
Yea this I understood, the peaks and lows are cut off, but now you're left with fragmented straight lines which must be "buffered" somehow to make one steady streaming line.But now this voltage has the shape of a half sine, there are still peaks and throughs (zeros actually). So you need the capacitor to turn that into "usable" DC, something resembling more a steady line.Comment
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Re: NCC KZGs really that bad?
No, at that point it goes to the switching section that turns it into higher frequency AC.
That's because the higher frequency allows reasonable sized in/out isolation xfmrs.
Then it gets rectified again.
Then come the filter caps.Mann-Made Global Warming.
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Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.
- Dr Seuss
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You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
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Re: NCC KZGs really that bad?
Nope, the peaks aren't cut off. The capacitor charges at the peak voltage of the waveform and attempts to hold the voltage at that level. That's precisely why ripple gets produced.A working TV? How boring!Originally posted by PeteS in CAComment
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Re: NCC KZGs really that bad?
I a linear supply, would you need low ESR caps? (Since there's no switching transistors.)Comment
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Re: NCC KZGs really that bad?
No. But you will need more capacitance (higher uF values).A working TV? How boring!Originally posted by PeteS in CAComment
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Re: NCC KZGs really that bad?
It does matter to a certain extent. But it doesn't need to be "low esr" for linear supplies.A working TV? How boring!Originally posted by PeteS in CAComment
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Mann-Made Global Warming.
- We should be more concerned about the Intellectual Climate.
-
Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.
- Dr Seuss
-
You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
-
Comment
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Mann-Made Global Warming.
- We should be more concerned about the Intellectual Climate.
-
Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.
- Dr Seuss
-
You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
-
Comment
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Re: NCC KZGs really that bad?
I've been trying to figure out how to build a super stable linear power supply. I don't really have the materials/knowledge to go about making a custom PCB for a switching supply of my own, which is highly dependent on layout.
Does low ESR (on a linear PSU) lead to more stable voltage/better ripple suppression? Any tips?
Would polymers make a difference?
Just massive capacitances?
Thanks.Comment
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Re: NCC KZGs really that bad?
I would maybe add KZE's as bad, too, at least the 3300uF ones. I recently had two boards with bad KZG, toghether with the 1500uF KZE's which looked good. However I did not measure them and it looks like I should have to becuase right now I look at old nForce 2 board with bulging KZE's 3300 uF/6,3 V.
Once again, there are 1500uF/16V ones too, optically good, I will desolder them and measure just for case.Last edited by Behemot; 05-31-2011, 03:46 PM.Less jewellery, more gold into electrotech industry!
Half of the computer problems is caused by bad contacts 
Exclusive caps, meters and more!Hardware Insights - power supply reviews and more!Comment
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Re: NCC KZGs really that bad?
No, KZE is a proven reliable series. Most likely it was a cascade failure.Comment
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Re: NCC KZGs really that bad?
No way. After recap it works just fine, no broken MOSFTET's.Less jewellery, more gold into electrotech industry! Half of the computer problems is caused by bad contacts
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Has anybody tested this product? Posting this question on a Facebook tech group I'm in got a few responses like "that kind of thing corrodes the tips" and "just using normal solder paste is much better" so I'm not looking for generic responses like that, but rather, does anybody know for certain whether this exact product is good or bad for soldering iron tips?
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A "nice" YoungYear unit? - Badcaps
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Hello guys!
I would like to ask your opinion on the hot air station Atten 858D or even 868D (there are many other producers of this very same product like W.E.R and so on).
Rough specifics:
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Temperature range: 100-450 celsius
I would want to remove and resolder the RAM BGA chips of a graphics card and I was wondering if it is plausible with a 858D (or 868D) or not? I have heard others say, that for a RAM sized BGA it is better to use a stronger hot air station, but I was wondering if...
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