Coil winding resources

[Pax Writer]

Hello all

I've started a new project which calls for some custom wound coils. Problem is that my knowledge about coils is basic at best, so I need some online resources about coils, solenoids and winding techniques. If you know of good sites, application notes or the like, please feel free to provide a link.
I have searched a couple of times, but I've had problems finding anything relevant.
The coils are meant to be used for a solenoid and will be run at a low frequency (5-25Hz if possible). It'll be low voltage but relatively high current (as high as the coil itself permits).
Any links and good advice is welcome. If you need any further info to be able to help, please post and I'll answer asap

Thanks in advance.

 

[Pax Writer]

No one with experience has some advice for a coil-newbie?

 

[stevez]

I think a lot of the coil-winding done by many who participate is for chokes, broadband RF transformer, RF coils and similar items that have a wound type construction. It sounds like your area of interest is in generating a mechanical force with the coil - that is certainly an area that is probably very well understood but more likely by people who are involved in the design and manufacturing of that kind of item. Two source of information that come to mind - printed books particularly engineering references and the other is from manufacturers. The engineering references are not likely to be on-line or at least open to anyone as they are usually protected by copyright. The manufacturers information may be available via trade publications specific to that industry - or it may be a trade-secret kind of thing -those things they keep to themselves so they stay ahead of competition.

Initially I was going to suggest some references and manufacturers but when I re-read your post and realized "solenoid" I stopped. Just didn't want you to think no one would take the time to respond.

 

[Pax Writer]

Hello Stevez

Thanks for the answer. Maybe you're right about the whole copyright and cloak-and-dagger thing. You're right that I want to make a mechanical force out of my magnets.
The type of questions I'm trying to find answer to right now is along the lines of:
- To get a stronger magnetic field, should I go for thinner wire/more windings or thicker wire/more current?
- For a given length and diameter of my solenoid, should I decrease the diameter of the core and spend the extra space on more windings or vice versa.

... But I think I'll try to locate some literature from the manufacturers' sites and mayby find a tesla coil forum. There are bound to be some knowledgeable people there

Thanks for the post

 

[Boncuk]

Hi Paxwriter,

the problem isn't solved looking for coils used in transformers. An AC-driven solenoid will "ring" (meaning the iron bar or piston will oscillate at AC-frequency) if wound the same way as a transformer. This method is used for simple door bells with a small hammer hitting the bell at mains frequency. The magnetic field around it has to be constant which requires a special winding technique, e.g. bifilar windings.

You might check with Webber (UK) or Festo (DE). They make AC-driven solenoids and probably are willing to give a basic idea about how to wind those coils.

Boncuk

 

[stevez]

Pax - your questions about wire/windings, etc are good and someone here might know the answer. It seems likely that the fundamentals needed to answer your questions would be part of many programs related to electronics. It does seem likely that you'd find answers to those basic things in some kind of common reference if you don't get a response here. Boncuk's comment is a good start at helping you work thru the basics.

If you have the time/resources it might be fun to experiment with designs. I rather enjoy taking a problem or question out to the workbench along with the basic research. Wind some coils, make some measurements - lots to learn.

 

[Boncuk]

Hi Pax Writer,

you might try this experiment. Wind 1/2 turns clockwise and continue with the same number of turns anticlockwise.

Wind the copper wire around a plastic hose. When finished stick a nail halfway inside and observe what happens to it when you apply low voltage AC.

If that arrangement of wiring keeps the nail at a steady position that kind of wiring will be OK. If it oscillates at supply frequency you might use it for a door bell.

Boncuk