find magnetizing force of magnet

[dor baruch]

How do I calculate the field strength of the pickup with and without the magnets?
Oersteds
or the magnetizing force of the magnet in oersteds to find the Magnetic Saturation of my iron pole pieces?

thanks

[David Schwab]

The pickup will have zero magnetic field strength without the magnets. What exactly are you asking?

[dor baruch]

sorry I'll give you an example
I want to know how much the pole pieces of the pickup induced by the pickup alnico magnet and the solenoid

so if i know that the saturation of 1018 steel is 1000 oe that wil get 19000 gauss
how i can get my magnatizing force on the steel to be 15 oe for 13000 gauss?

[David Schwab]

Why do you need it to be a certain gauss? Measure the magnet, and then put it in the pickup.

[dor baruch]

i want to know the effect of the magnet on the steel pole pieces if i know the
magneizing force effect on the flux density I'm sure I can learn from this Something about the sound I'm looking for

like what is the Advantage of flat Hysteresis loop!?

[David King]

I'd recommend trial and error, do you have a gauss meter? If there is a linear correlation between the magnet and the pole flux density it should be quite obvious after plotting a few points using different magnets. Once your poles reach saturation all bets are off.

[dor baruch]

hi david king
i make trial and error but i Must understand some basic things like
how much a guitar string in Average is inducing an emf through a coil?
how i Calculates the magnetic field force of the pickup (wire vs magnet core) with Known gauss of the magnet ?

thanks

[marku52]

Sounds like you need to learn to use FEMM, an open source finite element analysis program that can do magnetics (but only in 2D). It will tell you things like what is the flux density in the iron you place next to a magnet. The trick is you have to learn how to use it, and also, that it doesn't have models for all of the types of magnets we typically use. with enough effort, all these disadvantages can be overcome.

Finite Element Method Magnetics: HomePage

However, personal experience suggests that once you have a certain minimum required mount of magnetic force at the string, more isn't really helpful. So totally understanding the flux lines may not really be that useful

[dor baruch]

wow marku52
thanks
This is great!!!

[J M Fahey]

Just as a side note, the typical magnet in the typical guitar pickup is far from saturating the pole piece, usually it's a "too open" design, too much thin air in the path, which is equivalent to *huge* gaps.
Which are the typical solutions to avoid iron saturation.
A powerful (speaker magnet type) magnetic circuit could be designed, of course, where saturation might be considered, but such a pickup would "pull" strings *way* too much and probably sound horrible.
Although perhaps you might light a LED with the guitar output

[dor baruch]

My question is so what?
if alnico magnet is saturated its stiil sound good up to 7000 in alnico 2 and 13500 alnico 5DG
ceramic have up to 5000 soft ferosmagnets like nickel can be 4000 or 6000
iron have up to 19000 max saturatied so yes but what about nickel and stainless steel

[J M Fahey]

Do you plan to make nickel or stainless steel core pickups?

[dor baruch]

yes! i am In the final stages of planning and production
I create them as pure or bimetal\trimetal

[J M Fahey]

Well, maybe it sounds cooler to state so in the brochure, but actually humble SAE1018 steel is much better, magnetically speaking.
And SAE1010 (which I use for my speaker magnets) even better.
Each of these will require an anti rust coating, of course, such as Nickel (or Chrome/Zinc/etc.) but coat thickness is nil and has no magnetic effect.

[dor baruch]

hi j m fahey

i know that humble SAE1018 steel magnetically Superior but he has Specific magnetic saturation and 416,430,440c,436, have other magnetic saturation
so in a Specific pickups the can be More suitable for my Needs (Again maybe)

Why sometimes you prefer to use 1018 and not 1010 and 1020 and not 1018 Because they "sound different"...