ferrite beads

[till]

ok, i frequently read ferrite beads should be used in IC power supply line.

some questions: why not use small inductors like http://www.reichelt.de/bilder/web/B400/!SMCC.jpg
?

and for the beads, i got some AMIDON beads http://www.reichelt.de/bilder/web/B400/T20.jpg

diameter 6,48 mm
inner diameter 3,05 mm
thick 2,44 mm
AL (µH/100Wdg): 34
MHz max.: 30

and enamelled copper wire 0,6 mm diameter.

So how many windings of wire should i make with the wire trough the bead? Or what values of those inductors of the kind package looking like resistors? Shoul the ferrite bead near to IC like the capacitors, or should it be near to power supply to filter HF coming from powerline, regulators etc. ? What about a Filter chain like 1000uF, 100R, 220uF, 100uH, 220uF,ferrite bead, 10uF+100nf at IC?

[Jocko Homo]

It looks like what you have there is not a ferrite, but a powdered iron toroid, used for winding inductors.

Ferrites beads are usually specified as to what ferrite mix they are made of. Toroids for inductors are usually specified as to "max useful frequency", and uH/x turns.

A ferrite bead should be either a type 43 or 73 mix. There are a few other mixes that they are made with, but are not as common. Unless the supplier can tel you which mix, do not buy them unless you have lots of experience.


Jocko

[till]

Thanks for information. Its no problem, i got 10 of those "wrong" beads/torroids for free. Whatever i will do with them... I have no problem to get some ferrites with type 43,61,or 77 .

But please give me information how many windings i need, or what values for inductors, to make the power supply line for a DAC / AD1865NK.

My problem is not to get the right parts if i´m told which ones, but i have no information about values to use or a schematic to looks at.

In other words, i lack the experience you mention.

[Bricolo]

Jocko, I haven't found tha material used in the chokes I use
are they any good?

[Elso Kwak]

Originally posted by Bricolo
Jocko, I haven't found tha material used in the chokes I use
are they any good?

Bricolo,
If look at the graphs in the paper you submitted you will see that the BL02RN2 offer excellent attenuation at "CD frequencies".
Guido Tent is suggesting BLM31A J601SN1 also from Murata. These are SMD beads. (Farnell part# 581094)
No more hints from me, remember you are the student in electronics, I am just the bloody chemist.

[till]

Anybody who could give me some answers?

[Bricolo]

Originally posted by Elso Kwak

No more hints from me, remember you are the student in electronics, I am just the bloody chemist.

You know I also studied chemistry
I hope my teachers won't read this, but for the momment I learnt more from you and other people here on diyaudio than from them

[Elso Kwak]

Originally posted by till
Anybody who could give me some answers?

Hello Till,
Your coils are useless at high frequencies.

[Elso Kwak]

Originally posted by Bricolo



I hope my teachers won't read this, but for the moment I learnt more from you and other people here on diyaudio than from them

Now, is this a judgement of value on you or your teachers.....?

[till]

which coils, the SMCC ones, or the toroids Jocko allready told me are useless? What frequencies are we talking about?

- So how many windings of wire should i make with the wire trough the bead?

- Or what values of inductors is needed?

- Should the ferrite bead near to IC like the capacitors, or should it be near to power supply to filter HF coming from powerline, regulators etc.?

- What about a Filter chain like 1000uF, 100R, 220uF, 100uH, 220uF,ferrite bead, 10uF+100nf at IC?