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Pyramid Magnets - Focusing Flux to a Point



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pyramid magnets have been a real

fascination there's some people who

think that the geometric shape of a

pyramid has some mystical powers to it

I'm not sure if that's true but I do

know what they can do

with magnetic fields here's one of the

ones that is my largest pyramid magnet

this is four inches tall from here to

here it has a three-quarter inch square

top and it has a four inch square base

this is about a nine pound magnet and is

extremely powerful the customers who

have used this one I've had one

researcher who has been working with

this for several years and he used it in

his PhD research for magnetic

stress-relieving on welds he was having

to rent time on a large superconducting

magnet in order to run his experiments

but he found that the magnetic field

between eight and nine thousand Gauss

and in some cases a little over nine

thousand gals on this magnet was high

enough to accomplish his goals without

having to do anything else but to have a

static magnetic field that is

approaching a Tesla covering

three-quarters of an inch is quite an

enormous magnet this one is not actually

made from one piece if you notice

carefully you'll see the lines

indicating this was three pieces of

magnet material that was made and in

glued together and I've had this one for

several years it's been an enormous

magnet and had a lot of applications

here and in some cases we've just let

people borrow it for a little bit but

I've got this magnet one of the things

that we like to do is look at the

different sizes of pyramids I'm going to

move this one so it's out of our way

that is an N 45 pyramid magnet I also

have these two inch pyramid magnets this

is a two inch square base with a 1 H

square top that is one inch thick this

magnet has been by far the most widely

used pyramid magnet that I have when I

look at this one and I think about

how this one has been used it really

surprises me it started off as I wanted

to get a magnet that could focus the

magnetic field and make it stronger now

keep in mind that this material is is

such that when it's magnetized it is

magnetized in straight lines and as the

magnetism is traveling through the

material in a pyramid shape it would

normally want to come out through the

sides but it sees that its ability to

stay inside the material the material

has a much higher permeability than air

and so it stays in and it intensifies

the field on this end what we've done is

reduced the cross-sectional area by a

factor of four we went from four square

inches on this end to one square edge

here now you don't get a 4x

multiplication of your strength but you

do get a significant increase in field

strength this one would be somewhere in

these 7000 Gauss across this surface

here's some of the applications we've

used this for it is been fantastic and

has worked extremely well in every

application where customer is tested it

at erasing the highest grade of digital

tapes digital storage tapes digital

videotapes audiotapes whatever it is one

pass past this magnet will wipe it out

sometimes we will use it to make sure

we're getting stronger fields and

penetrating all the way through

three-quarter inch and one inch thick

tape we will put the button but put on

the base of this a two inch in fifty

cube when you put that on there you

extend this magnetic field some so that

has enough penetrating power to go all

the way through even the most resistant

tape it will wipe it out we also have

had a hard drive manufacturer that has

had device made this very quickly erases

hard drives they simply slide the hard

drive in between an array of two of

these where one is above the other and

as soon as they slide it in rotate the

platter the drive as clean as a virgin

to a virgin tape or a virgin drive again

we also have a smaller version of our

pyramid that say one each pyramid a lot

of people get this one for the purpose

of seeing how intense this field is in

this field actually gets very strong

it's around a seven thousand seventy

five hundred Gauss field as well but

it's only one eighth of an inch square

this

has a 180 square base 1h tall and a 1/8

the 1/8 inch square top a lot of people

want to put these two together so we'll

do that with this example I'll take the

2h pyramid but we definitely want to use

a wooden wedge so that we do not break

anything they snap together slide the

wedge out and it sits on top of it

making much closer to a real pyramid

then a truncated frustum in you can get

the idea how the other one was made the

four-inch one by stacking it up and this

is a this one would actually be a 2 H

square tapering to 1/8 of an inch thick

and would be 2 inches tall as a pyramid

we also have some smaller ones a lot of

people just want to see the smaller ones

and how they work this one is very tiny

10 millimeters across on each base this

one's even an example of a three-sided

pyramid as opposed to the four-sided

ones and it tapers to a 6 millimeter

triangular shape across the top and it's

10 millimeters thick and this gives us

another good example of the pyramid

forces one of the things that we want to

do is look at a haulback array that I

have made one of the strongest magnetic

fields that I've seen or read about

anywhere that has a static magnetic

field let's take a look at this giant

array this is my 8 pyramid magnet these

are roughly 2 inch square bases they're

a little over an inch thick about an

inch and a quarter thick tapering to

what is inside is about a 1/2 inch

square surface you will notice that

these are eight each of these have been

magnetized differently they have two of

these that are magnetized from the base

to the tip and they're the opposite

poles to help improve the haulback

process what I've done is had these

magnets in the corners magnetized at a

45 degree angle to the base so these are

not well I could do normally when you

make a hole back they use cubes and just

rotate the cube in this case I actually

had it magnetized at a 45 degree angle

and put in place this one is magnetized

a

Ross from size parallel to the bases

this one also is magnetized at 45

degrees in the other direction to come

around to this one what it creates is an

extremely intense field in between these

two magnets it's mounted in this

extremely large steel array and what

we've done is stacked little magnets

inside across the normal gap here we

would have about an eleven to twelve

thousand Gauss field strength in that

entire area just straight across here

but one of the things I like to do is

use my magnet stacking technique which

really amplifies the magnetic field I've

got these special magnets that are thin

and in 50 material and they allow me to

focus the field to between two this half

or actually this is about a four or five

millimeter field or gap between them and

it's two five millimeter square surfaces

so basically a five millimeter cubic

volume of space and this permanent

magnetic field in this area has measured

in the 17 16 thousand seven hundred to

seventeen thousand gauss area depending

on the probe and when i've tested it and

so this magnetic field is incredibly

powerful we even made this one for when

you don't use the magnets tacking it we

have a small hole in it that goes all

the way through this magnet to the

center and it was for the purposes of

doing some research i had two of these

made one of them for a customer that was

doing research and he needed a way to

create in in that gap on the surface of

either of these magnets that's what the

field is when you combine that you get

three tesla in the air gap on a

permanent magnet field so this is an

enormous leap our 'fl magnet and it's

made from eight of these pyramid magnets

so as you can see there are many

applications for permanent magnets made

in the shape of a pyramid if you have

any other questions or you have some

faults or ideas about pyramid magnets

don't hesitate to ask