capacitor discharge type magnetizer

[dor baruch]

hi
I want to buy capacitor discharge magnetizer for charging alnico and Ferrites magnets
to a Specific amount.

i know that in dc magnetizer i need 3(alnico)-10(Ferrites) KOe or 20,000 Amp / turns / inch for Ceramic

so my q is how much joules i need?


+ i think i cant get Variable charging with dc magnetizer like this
Am I wrong?

Gaussmeter, Magnetizer and Pole Finders - Master Magnetics, Inc.

thanks

[David King]

I think you would be able to get more control with the DC magnetizer than with a discharge one.
I'd ask the company if their DC model can be run on a lower voltage via a transformer or a Variac to dial in the Joules you want.

[SonnyW]

You are right that on the Mag24C type magnetizer it isn't variable. But I have has some good luck getting a specified charge on Alnicos by charging them up fully and then using a toolmakers plate demagnetizer with some fixtures that I made to demagnetize them a specified amount. I made the fixtures out of wood and MDF board and they hold the magnet or pickup at a specific distance from the plate on the demagnetizer. Here is a thread with a little about it. demagnetizing alnico 5 rods I know I posted some photos once of my fixtures, along with some photos of my notes on the amount of demagnetizing for each in another thread. I think it was here, but I can't find that thread now. There is a little more about it on the shop tour page on my website.

[dor baruch]

thanks david and sonnyw

i cant find where to buy the Mag24C type magnetizer
the only one i find cost now 1000$ i think its to much

can you help me find a Cheaper one
The company itself does not come back to me

[SonnyW]

hi dor,
I found the other thread I mentioned it is here
http://music-electronics-forum.com/t25710/

I got mine from Master Magnetics and it was about $600, but that was some time ago, maybe 4 years?? I don't see them on their website anymore, but they might respond to an email about it. I think the company that makes them is Magnetool, that is what it says on the nameplate of mine, you might also try to contact them for a quote.
Electromagnets, Magnetic Tools, Demagnetizers, Chucks | Magnetool

[ReWind]

Could one also use wooden spacers when charging magnets to reduce the initial charge level?

Mostly just curious, since one can nab one of those demagnetizers for $40-50 and it's a worthwhile tool to have.

[SonnyW]

Interesting idea, and easy to test, so I just tried using spacers while charging and there is some effect. Regular A5 humbucker magnet degaussed to 65 gauss. Charged in Mag24C with approximately 3/8 inch wooden spacers on each side, measured in the middle at a mark, it read 695 gauss. Then charged it again with no spacers and it went up to 715 measured at the same mark. I didn't have any other thicker spacers handy, so only one data point, but looks like it would work. One slight inconvenience is holding the magnet in the right place, I had to put another wooden spacer under it to hold it up.

[dor baruch]

thanks sonnyw
Master Magnetics didnt respond to my email and i think Magnetool made your demagnetizer and not your magnetizer?
i find the Part No. MAG24C at other site for 1000$ and 250$ shiping the q is if i can find it for less

by the way 600 guass is 600 millitesla and its 6000 guass
1 millitesla=10 guass

[SonnyW]

dor, no here are photos of the nameplates and invoice. My magnetizer was made by Magnetool but it was bought through Master Magnetics. My demagnetizer was made by phase II+ I bought it used on ebay.

[Rosewood]

Hey Sonny, is that an old Hickok milliamp meter behind your demagnetizer?

[SonnyW]

Hey Sonny, is that an old Hickok milliamp meter behind your demagnetizer?

It isn't a Hickok, it was made by Sensitive Research Instrument Co. in New Rochelle, N.Y. (0-50 ma) The original calibration is on the back dated 4/26/1960. It's handy for some things and still accurate. Kind of a long story how I came into it. Part of one of the best lucky finds I ever happened on. I was working as an electrician for the University of Texas at Arlington, while I was attending school. At that time the school had an Industrial Arts department that they were going to close down and transfer to a local junior college. After the junior college had gotten all they wanted out of the building, the school let all the professors go through and take what they wanted of what was left. There was still some stuff left after that, among it was this meter and several others. It was all military surplus gear. The University was not allowed to sell it so they told the maintenance guys to get what they needed for the maintenance shop. So several of us went over there in the school's truck and loaded up a few things for the maintenance shop. Then the supervisor in charge said something like "We can't sell any of this stuff and it is all going to the dump tomorrow so I think I am not going to lock the building tonight. I hope there is less of it for us to cart off tomorow. I would hate to have to make two trips." I got several meters out of that deal, some were pretty old, but this one was the best of the lot. That was in about 1970, so it was only 10 years old at the time.

[Rosewood]

It isn't a Hickok, it was made by Sensitive Research Instrument Co. in New Rochelle, N.Y. (0-50 ma) The original calibration is on the back dated 4/26/1960. It's handy for some things and still accurate. Kind of a long story how I came into it. Part of one of the best lucky finds I ever happened on. I was working as an electrician for the University of Texas at Arlington, while I was attending school. At that time the school had an Industrial Arts department that they were going to close down and transfer to a local junior college. After the junior college had gotten all they wanted out of the building, the school let all the professors go through and take what they wanted of what was left. There was still some stuff left after that, among it was this meter and several others. It was all military surplus gear. The University was not allowed to sell it so they told the maintenance guys to get what they needed for the maintenance shop. So several of us went over there in the school's truck and loaded up a few things for the maintenance shop. Then the supervisor in charge said something like "We can't sell any of this stuff and it is all going to the dump tomorrow so I think I am not going to lock the building tonight. I hope there is less of it for us to cart off tomorow. I would hate to have to make two trips." I got several meters out of that deal, some were pretty old, but this one was the best of the lot. That was in about 1970, so it was only 10 years old at the time.

I have a Hickok meter that looks very close to yours, that old bakelite material I assume. Mine must have lived it's life similar to yours in some lab because there is no scratches or damage and works perfectly. I love the old high quality test equipment.

[SonnyW]

I have a Hickok meter that looks very close to yours, that old bakelite material I assume. Mine must have lived it's life similar to yours in some lab because there is no scratches or damage and works perfectly. I love the old high quality test equipment.

Yes, it is that old bakelite material. That is a great material too. I fail to see why it isn't used at least some these days, unless it is because of planned obsolescence. Bakelite molding isn't hard to do at all, and it is tough and durable. I like the old high quality test equipment too, and Hickok was certainly considered among the highest quality. I do have one Hickok meter - a 6000 tube tester. I think SR was a competitor of theirs just not as well known. I bet they are very similar. I also have an old Simpson 260 multimeter that was given to me as a high school graduation present that I use frequently for phase testing on pickups. Some of the other old meters I have don't get used a lot, but they add a little 50's decor to my shop. Three of the (mostly Weston) ones hanging at the top of the wall in the last photo below are more of the ones I got from the old Industrial Arts school. Here they are for your viewing pleasure.

[dor baruch]

thanks sonnyw
iI contacted magnetool and i buy it from them for 600$