ZenV4 PSU noise

[PsykoK]

I know that no the first and no the last thread about "zen4 PSU" and I apologize to create on more.

I designed 2 boards for the C-L-C filter from my Zen4 but I have a question:
-What is the best choice between these 2 boards to have less noise around it?

Why this question?
Because on of this board would be under the Zenv4 board!

I plan to use the following parts to build this board
- Aerovox ALP22 10000uF 63v
- Wima MKP10 4.7n
- 2.2mH air-core inductor ( 0.60 ohm, 300W)







I think that the 2nd solution is a litel better because caps are equally distributed on either side of the inductor.

[Nelson Pass]

Depends on the ripple rating of the caps. Often, most of the
caps must be used in the first bank because the ripple
current is high. Figure on a ripple current rating 4 times
the DC draw of the circuit, and parallel enough caps to
get that figure. The remainder can go after the inductor.

[aaronpiet]

my zen v4 pair in test is running now with only one cap after the bridge, it's a 10.000uF / 63 V SIKOREL and I have absolutely no audible hum on my speakers. The SIKOREL run up to 125°C!
This cap has a ripple current of 30A at 100Hz at 85°C!, in comparison with normal caps which have between 5 and 10A.
One sikorel in Germany is about 25€, the others between 5 and 10€. On the cap I have seen a ripple current of 2V peak to peak, stabilized I see 10mV - the same value as described in Zen Part3. My zen has no R1, means that it has about 2.6A current.

[aaronpiet]

another one:
the temperature limit of the SIKOREL is 125°C, in my ZEN I have about 55°C

[chris ma]

Don't really mean to thread jack here but I have a quick question wanted to ask for a long time. How do one measure the ripple voltage for a capacitor when the amp is running? Last time I tried, the prob of my MMeter also welded to the leg of the cap, when I set the dial of the meter to measure AC across the terminals of a cap. A real newbie question.

Regards,
Chris

[aaronpiet]

Hi Chris,
is it possible, that you tried to measure ac-current instead of ac-voltage? I have done the measurements on a scope.
Peter

[joensd]

Hi Chris,
is it possible, that you tried to measure ac-current instead of ac-voltage? I have done the measurements on a scope.
Peter

If I understand you correctly this (measuring AC-Current over cap terminals)would have created a big short. Ouch

The scope is definitely the nicest way to check ripple but a good True RMS meter would do the job likewise.


Jens

[chris ma]

Yes, stupid of me, I tried to read/learn from books and magazines, but they don't normally tell you practical things like these. Anyway thanks for all your answers, scope is the right tool then; enough for me here intruding.

Sorry PsykoK.

Regards,
Chris

[PsykoK]

Originally posted by chris ma
Yes, stupid of me, I tried to read/learn from books and magazines, but they don't normally tell you practical things like these. Anyway thanks for all your answers, scope is the right tool then; enough for me here intruding.

Sorry PsykoK.

Regards,
Chris

No problems!
Your question were good and interest me too .


I check the datasheet from my caps and I found that :

D.C. leakage current
After application of rated d.c. voltage for 5 minutes at 20°C,
the d.c. leakage current shall not exceed
(0.006 Cr Ur) µA. Where Cr is the rated capacitance in µF and
Ur is the rated d.c. voltage.

But for the moment I can't found any other technical data about these sort of caps!


An other solution ofr me is to use an other sort of caps from Vishay Roederstein :EYN07CB510J02 (10 000uF 63v)
They have very interisting spec:
ESR@120Hz : 0.035 ohm
Z@10KHz : < 0.030 ohm
Ir @120Hz, 85°: 5.3 A

The Ir is mabe to slow?

[aaronpiet]

the Roederstein CAPS are ok, but you will need two of them per channel.
the link for the epcos(siemens) SIKOREL is here:
http://www.epcos.com/inf/20/30/db/alu_01/01090117.pdf