PLEASE HELP!

Found a few of these in a cigar box marked "coils" at an estate sale. 2" diameter by 1 1/2" tall. Marked "Ferrodyne Corporation" and "FSI-6". ONLY internet reference about company is that it folded in 1993.

At a guess I'd suggest an electromagnet, possibly for holding a door closed or something similar?

That was my first thought, but they made antique style valve radios.

My guess from the logo is it was once used in a primitive power supply by a company that later got into military spare parts (Hence the CAGE number) but was short-lived from the lack of design experience on how to cool coils. (expired co.) Perhaps it was kept for sentimental reasons as a source of revenue for people involved with this once LA,Ca company.

Technically, it is an inductor, which opposite of a capacitor but similar in that it stores energy, yet to smooth (integrate) the flow of current.

An inexpensive electronic component tester would be able to tell you right away what this is. Here is one for about $20.00


The device tests coils, resistors, capacitors, transistors, diodes, and other semiconductors. The read-outs are as accurate as a digital multimeter.

Wasn't Ferrodyne the company in the Terminator movies?

Thanks, guys. It reads dead short on ohm meter, and touching an AA battery to the terminals made spark, but NO magnetic reaction.

Johnnie Boy said:

Thanks, guys. It reads dead short on ohm meter, and touching an AA battery to the terminals made spark, but NO magnetic reaction.

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Possibly because it has no metalic or ferrite core, how much do they weigh?

A DMM will not energize nor give a reasonable result to the inexperienced. Inductors look pretty dead without experience or proper design application.

It could be a rare collector's item like a Marconi Radio or a Roman coin, yet, I have yet to see such items worth much.

All inductors have resistance and there are limits to L/R ratios so one can estimate one from the other given geometric and the assumption it uses an iron core like the original name Ferro= iron and Dyne=power.

My quick search induces (pun intended) the result that Ferrodyne was major force in radio supply about 1 century ago after Bell and Marconi invented the Radio. The AM radio was then what the internet is today. Although this vintage radio uses a "Ferrodyne chassis" it would not use this component as inductors were not very accurate for tuning and thus had to be tuneable and shielded, but could be used to filter noise voltage with low current in this small size. It does not appear in this radio but may have other historical/personal significance.




I yellow filled all the tuneable shielded canned inductors used in this radio.

Johnnie Boy said:

Found a few of these in a cigar box marked "coils" at an estate sale. 2" diameter by 1 1/2" tall. Marked "Ferrodyne Corporation" and "FSI-6". ONLY internet reference about company is that it folded in 1993.

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BTW, are they in a 'Potted' container?

Weight is 11.2 oz, and it's "can" is steel.

Just as 'similar' (but smaller) examples:

Not an electromagnet. Hole through center is only about 1/8", and it's not even counter-sunk. I touched a battery to it and there was no magnetism, just sparking.

Johnnie Boy said:

Not an electromagnet. Hole through center is only about 1/8", and it's not even counter-sunk. I touched a battery to it and there was no magnetism, just sparking.

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A small battery might not be enough?.

In any case, what does it matter what it is? - if you don't recognise it, then you don't need it

Johnnie Boy said:

Thanks, guys. It reads dead short on ohm meter, and touching an AA battery to the terminals made spark, but NO magnetic reaction.

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If they read 0 ohms or close, they may not be magnets, if they were I would expect at least 5 Ohms. Minimum.

I buy and sell things from garage, estate and yard sales to make money to pay my bills. Many times I buy things that I have no idea what they are or how much they're worth on a "hunch". These mystery "coils" are one of those items. If I can find out what they're for, then I might find a buyer.

There is a magnetic loop sliced here which has a strong force when the gap is closed with a flat magnetic surface plate.

Nigel Goodwin said:

Just as 'similar' (but smaller) examples:

RS PRO Double Door, Single Door Access Control Door Magnet, 150N Holding Force 12V dc | RS

uk.rs-online.com

5.83.01 | Mecalectro Holding Magnet, 1450N Holding Force 24V dc | RS

uk.rs-online.com

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Only similar in shape but neither contents nor coaxial magnetic rings

There is something nostalgic about gold ink logo and a rubber mold ink stamped part number