[sdiy] Ferrite beads on module power inputs

[David]

Now for a more naïve, but not totally uninformed answer.

As I've been learning and re-learning electronics and studying the designs
of those who make their designs available (untold thanks to you), I've
noticed a couple of things.

1. It doesn't take a lot of board space to add the spot for a ferrite bead.
2. The space can also be used for a thermal fuse, like John Blacet uses.
3. They are probably unnecessary if you have any kind of a new design,
reasonable power supply.
4. They have to filter some high frequency rail noise, maybe kill a spike or
two.

So, following the likes of Synthtech and others, I put them on the PCBs I'm
laying out and I put them in because they might help and I haven't seen any
compelling reason for not using them.

David

David Ingebretsen

David M. Ingebretsen, M.S., M.E
Collision Forensics & Engineering, Inc.
2469 E. Ft. Union Blvd., Ste 114
Salt Lake City, UT 84121

dingebre at CFandE.com
dingebre at 3dphysics.net
801 733 5458



-- -----Original Message-----
-- From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
-- bounces at dropmix.xs4all.nl] On Behalf Of David G. Dixon
-- Sent: Tuesday, March 22, 2011 5:46 PM
-- To: 'Neil Johnson'; synth-diy at dropmix.xs4all.nl
-- Subject: Re: [sdiy] Ferrite beads on module power inputs
-- 
-- > So I'm curious to hear from those who do use them as to why,
-- > and any evidence or calculations which show that they do have
-- > some measurable and useful effect in synth module supply circuits.
-- 
-- Never use 'em, never miss 'em.
-- 
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