Demagnetising Tool/Tool Demagnetiser

[mrfeedback]

I have a watchmaker customer who complained to me the other day about the problems caused to him in his work by his miniture screwdrivers becoming magnetised and asked me if it is possible to demagnetise them effectively.
A minutes thought and a dip into the junkbox produced an old washing machine water valve solenoid coil.
These coils are rated for 240V operation so I connected a power lead to it and tried it out.
Inserting a magnetised screwdriver into the center hole and then slowly drawing it back out and moving it a long distance away before switching off the coil current gave a totally demagnetised screwdriver that would not pick up even the tiniest sliver of iron.

There have been comments here on the forum of deleterious sonics caused by magnetic components and component leads.
This arrangement may be very effective in demagnetising components before fitting to a pcb.
Maybe this informatiuon is useful to some of you.

Eric.

[chris ma]

I wonder is the Bedini Ultra Clarifier work with the same theory so that the treated CDs are "better" read by the laser beam.
Anyone knows how the Clarifier works?

[MRehorst]

Originally posted by chris ma
I wonder is the Bedini Ultra Clarifier work with the same theory so that the treated CDs are "better" read by the laser beam.
Anyone knows how the Clarifier works?

Two points to consider:

1) CDs are read optically. There is no magnetic pick-up, which is fortunate because
2) the shiny layer in a CD is either gold or aluminum, neither of which is magnetic. There is nothing to "demagnetize".

I believe the Bedini Clarifier works on the same principle as the Mpingo disk.

MR

[Peter Daniel]

I've read here on the forum that the layer is not pure aluminum, but an alloy with some magnetic components.

[chris ma]

True MR, but laser beam has to pass thru plastic or what ever man made material, and it must has a (?) index for light to pass and if this material holds static charges and the CD being spinning at high revs so that it seems stationary relative to the beam, for electromagnetic force can bend light waves if I recall correctly, then it may affect the "read" by the laser. This is going way over my head/knowledge.

[peranders]

Originally posted by mrfeedback
I have a watchmaker customer who complained to me the other day about the problems caused to him in his work by his miniture screwdrivers becoming magnetised and asked me if it is possible to demagnetise them effectively....

I have the thing, work very good.

http://www.elfa.se/elfa/produkter/se/20/2023750.htm

It's two magnets. I'm still puzzled how it works but it does, very effectivly, totally passive. Cheap also, 25 USD.

[mrfeedback]

Peranders, I had one of those years ago and it was not nearly as effective as the solenoid demagnetiser, although it did a good job of remagnetising.
USD$25.00 - you must be kidding me - you got seriously ripped off on that one.
BTW the solenoid version was free out of my junkbox, and I gave it free to my customer - Win/win situation.

Eric.

[mrfeedback]

I believe the Bedini Clarifier works on the same principle as the Mpingo disk.

And what principle is that ?.

Eric.

[mrfeedback]

This is going way over my head/knowledge.

Better to keep quiet until you have the facts eh Chris.

Eric.

[mrfeedback]

Damage or obscuring needs to be about 2mm long on the disc surface before error concealment occurs - less than this and the Reed Soloman coding is used to properly correct data errors.
Disc static charge may perhaps attract the objective lens, and subtley change focus, or cause focus servos to draw noise currents and modulate the audio stage power supplies.

Eric.