Hi folks,
A quick question to all those versed in the art of inductor winding.
I'm tempted by the idea of making my own crossover inductors. I've got access to a grand inductor winding app. All you do is insert the inductance value you want and the thing spits out the diameter of the air gap (or the bobbin diameter if you prefer), the width of the coil, and how many turns in whichever AWG you prefer. It gives values from 24AWG to 10AWG.
I've chosen for the sake of convenience, to use 18AWG which is 1.04mm diameter, for any of the values I need for a crossover project, and others which may arise if I need more.
Enamelled copper wire, not being cheap, and certainly not cheap to freight in meaningful quantities, needs for economy sake to be sourced from Australia, in which I have the great fortune to live.
I could have avoided all that blathering above by asking whether 1mm wire which I can get locally can be substituted for the 1.04mm specified, and retain all the same parameters...turns, bobbin diameter, bobbin thickness etc.
It's only .04mm difference, but sometimes these things matter...
As you can see, I know nothing on this subject, so this is a real noob query.
Thanks in advance, Martin
A quick question to all those versed in the art of inductor winding.
I'm tempted by the idea of making my own crossover inductors. I've got access to a grand inductor winding app. All you do is insert the inductance value you want and the thing spits out the diameter of the air gap (or the bobbin diameter if you prefer), the width of the coil, and how many turns in whichever AWG you prefer. It gives values from 24AWG to 10AWG.
I've chosen for the sake of convenience, to use 18AWG which is 1.04mm diameter, for any of the values I need for a crossover project, and others which may arise if I need more.
Enamelled copper wire, not being cheap, and certainly not cheap to freight in meaningful quantities, needs for economy sake to be sourced from Australia, in which I have the great fortune to live.
I could have avoided all that blathering above by asking whether 1mm wire which I can get locally can be substituted for the 1.04mm specified, and retain all the same parameters...turns, bobbin diameter, bobbin thickness etc.
It's only .04mm difference, but sometimes these things matter...
As you can see, I know nothing on this subject, so this is a real noob query.
Thanks in advance, Martin
thats less than 1% difference in diameter. probably not a big deal
That said however it always best to buy a cheap inductance meter when making your own coils. The reason is while the clacs might be good , the execution ( unless well automated ) is usually not so great. Tightness of wind, exact layment of wires, etc can add up to a 10% or more end result.
well maybe not so cheaqp, heres one anyway. I find meters like this to be essential
Portable Digital LC Inductance Capacitance Meter
That said however it always best to buy a cheap inductance meter when making your own coils. The reason is while the clacs might be good , the execution ( unless well automated ) is usually not so great. Tightness of wind, exact layment of wires, etc can add up to a 10% or more end result.
well maybe not so cheaqp, heres one anyway. I find meters like this to be essential
Portable Digital LC Inductance Capacitance Meter
Thanks lowmass,
I didn't think it would make much difference...
An LCR multimeter would be one essential I'd look for.
As for the execution, I have a tiny lathe which could work well for this scheme. A simple reed switch, a neo magnet glued to the chuck, counting through a hacked calculator.
Bobbins for various sizes would be a chore to make but once made should make repeatability easier. I've worked out how to design the bobbins to allow for feeding in zip ties to tie down a coil before dismantling the bobbin.
Truth is, for my needs for this loudspeaker project needing only four coils, it would be easier to just buy the buggers, but this is DIY after all....
Cheers, Martin
I didn't think it would make much difference...
An LCR multimeter would be one essential I'd look for.
As for the execution, I have a tiny lathe which could work well for this scheme. A simple reed switch, a neo magnet glued to the chuck, counting through a hacked calculator.
Bobbins for various sizes would be a chore to make but once made should make repeatability easier. I've worked out how to design the bobbins to allow for feeding in zip ties to tie down a coil before dismantling the bobbin.
Truth is, for my needs for this loudspeaker project needing only four coils, it would be easier to just buy the buggers, but this is DIY after all....
Cheers, Martin
Thanks Tweet,
That's a fantastic find, at those prices I wouldn't bother making them. I need a 1.1mH for this job and SpeakerBug only offer a 1mH that i can see. Will that be near enough?
****eriksquires****. The way I understand DCR is that it should be as low as possible for crossover inductors, so I imagine that a thicker gauge will offer less DCR. I guess I would look for the thickest gauge wire I can find at the best price point. I have to remember the cost ratio for the fairly budget speakers I'm building, and although I want the best crossover components, I don't want the cost to start running away.
Tweet has given me an excellent lead for inductors here in Oz...
Thanks both for your inputs...
Cheers, Martin
That's a fantastic find, at those prices I wouldn't bother making them. I need a 1.1mH for this job and SpeakerBug only offer a 1mH that i can see. Will that be near enough?
****eriksquires****. The way I understand DCR is that it should be as low as possible for crossover inductors, so I imagine that a thicker gauge will offer less DCR. I guess I would look for the thickest gauge wire I can find at the best price point. I have to remember the cost ratio for the fairly budget speakers I'm building, and although I want the best crossover components, I don't want the cost to start running away.
Tweet has given me an excellent lead for inductors here in Oz...
Thanks both for your inputs...
Cheers, Martin
This is how I went about it Rolling Your Own (an adventure in coil winding) part I - diyAudio and rolling your own (an adventure in coil winding) part II - diyAudio
Someone had a great idea on the silk purse from a sows ear thread which was that you could get wire for coil winding from old electric motors.
I got my wire from blackburn electric wires, the link is in the first blog post.
Tony.
Someone had a great idea on the silk purse from a sows ear thread which was that you could get wire for coil winding from old electric motors.
I got my wire from blackburn electric wires, the link is in the first blog post.
Tony.
Thanks guys, Lojzek and wintermute...
The thing that would bother me is that using the inductor calculator I've got, the specs call for different bobbin sizes for every value. Not too bad if it's only a couple of inductors but of course much worse if one had to machine a bobbin, say from nylon, for every value required, should I require more for possible later projects.
Tweet led me to an Aussie site that has most of the values I need, in various wire gauges from which to choose, and will adjust a coil from a higher value to one of lower value. For instance I need a 1.1mH, and their nearest is 1.2mH, so they will unwind back to the required value, for free. The prices are the best I've seen and the postage is pretty cheap.
So I dunno, am I up for all the buggering around making them, with all the uncertainty involved, or do I just shell out the dough and get a guaranteed product?
I know only I can answer that, so I'll need to cogitate. I'm retired, so time isn't an issue but as the wife reminds me, there are always other non-speaker jobs around the house...
I checked out Blackburn, (no pricing) and your continuing adventures *wintermute* and I think you've done a pretty decent job...
Cheers, and thanks to all for your help. Martin
The thing that would bother me is that using the inductor calculator I've got, the specs call for different bobbin sizes for every value. Not too bad if it's only a couple of inductors but of course much worse if one had to machine a bobbin, say from nylon, for every value required, should I require more for possible later projects.
Tweet led me to an Aussie site that has most of the values I need, in various wire gauges from which to choose, and will adjust a coil from a higher value to one of lower value. For instance I need a 1.1mH, and their nearest is 1.2mH, so they will unwind back to the required value, for free. The prices are the best I've seen and the postage is pretty cheap.
So I dunno, am I up for all the buggering around making them, with all the uncertainty involved, or do I just shell out the dough and get a guaranteed product?
I know only I can answer that, so I'll need to cogitate. I'm retired, so time isn't an issue but as the wife reminds me, there are always other non-speaker jobs around the house...
I checked out Blackburn, (no pricing) and your continuing adventures *wintermute* and I think you've done a pretty decent job...
Cheers, and thanks to all for your help. Martin
Hello Martin, there is hardly any uncertainty while you are here, with all the experience from members accumulated. I can have it calculated for you any inductance with any bobbin size, if you choose so. ARTA labs software suite gives you a free LCR meter. Only a resistor and some hook up wire needed.
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