Mouser caries two different J.W. Miller vertical toroid inductors from the 2100 series. Different core material? There is also a third, low loss "LL" core which Mouser doesn't seem to list that I could find somewhere else. Which style would have the best performance in the output of a Tripath 2050 for mods of the Sure 2x100 amp module. The low loss core shows the biggest change in inductance between low load and maximum current. Almost 50%.
http://www.bourns.com/data/global/pdfs/2100_series.pdf
http://www.bourns.com/data/global/pdfs/2100ht_series.pdf
http://www.bourns.com/data/global/pdfs/2100ll_series.pdf
Do the Carbonal cores that people are using to wind their own toroids exhibit a similar amount of inductance change? Is this drop in inductance only decreasing rapidly, all toward the end of the maximum current rating that we never listen to? Or, is it also an indication of drooping inductance all through the usefull range of 0-2 amps?
http://www.bourns.com/data/global/pdfs/2100_series.pdf
http://www.bourns.com/data/global/pdfs/2100ht_series.pdf
http://www.bourns.com/data/global/pdfs/2100ll_series.pdf
Do the Carbonal cores that people are using to wind their own toroids exhibit a similar amount of inductance change? Is this drop in inductance only decreasing rapidly, all toward the end of the maximum current rating that we never listen to? Or, is it also an indication of drooping inductance all through the usefull range of 0-2 amps?
I have some inductors you can have if you want.
You can choose from either some used ~11uH toroids removed from a Tripath amp, or some new C&D Technologies 10uH 13A bobbin inductors (part #1410213).
If you get back to me soon, I'm on my way to the post office anyway.
You can choose from either some used ~11uH toroids removed from a Tripath amp, or some new C&D Technologies 10uH 13A bobbin inductors (part #1410213).
If you get back to me soon, I'm on my way to the post office anyway.
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Off the shelf
Thanks, but I am trying to come up with something off the shelf that we can buy on a continuing basis.
Thanks, but I am trying to come up with something off the shelf that we can buy on a continuing basis.
No problem.
I'm no expert, but I don't think the toroids you linked to above would be suitable. I think these are meant for power supply applications where the constant sloping saturation curve doesn't matter as much?
If winding your own is a possibility, I suggest trying to get ahold of some Ferroxcube gapped toroid cores.
http://www.ferroxcube.com/appl/info/class D audio amplifier.pdf
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Arjen sell some nice inductors at a very reasonable price
http://cgi.ebay.com/Choke-coil-for-class-D-amplifiers-10uH-3A_W0QQitemZ260469362956
and there are people who have experiences with those
http://www.diyaudio.com/forums/showpost.php?p=1889611&postcount=289
http://cgi.ebay.com/Choke-coil-for-class-D-amplifiers-10uH-3A_W0QQitemZ260469362956
and there are people who have experiences with those
http://www.diyaudio.com/forums/showpost.php?p=1889611&postcount=289
No ready made output toroids available?
Is it just me or doesn't it seem weird that there is only one guy in the whole world, hand winding one value of toroid, that can be recommended for the output of a Tripath? Hours of searching the forums and I have come up with no recommended part numbers. I know many people are finding it fun to wind their own coils but there must be a supplier that has a range of ready made coils that were designed for these amps.
Is it just me or doesn't it seem weird that there is only one guy in the whole world, hand winding one value of toroid, that can be recommended for the output of a Tripath? Hours of searching the forums and I have come up with no recommended part numbers. I know many people are finding it fun to wind their own coils but there must be a supplier that has a range of ready made coils that were designed for these amps.
I've been considering replacing the inductors in my Arjen amp (same as the ones pictured above) with air core inductors, which I've read deliver an 'airier' presentation.
Just wondering if anyone would happen to know of a source for 10uH air core inductors, or a guide that will explain how I can wind my own?
Cheers.
(this has got to be the coolest smiley ever)
Just wondering if anyone would happen to know of a source for 10uH air core inductors, or a guide that will explain how I can wind my own?
Cheers.
(this has got to be the coolest smiley ever)
I was going to say that as long as no one suggests using air core coils, you'd probably be fine. Though specialized fully shielded high frequency cores would be preferable.
Air core coils in high frequency circuits is a big mistake though, and will most probably have the police knocking down your door, and thrown you in jail within hours of turning it on.
And even if you can somehow manage to fully shield those (which is pretty near impossible) air coils are good in low frequency circuits, especially speaker crossovers where core saturation will vary a lot and take time to build up, whereas in high frequency circuits core saturation is something that is near constant and near instant, and therefore calculated into the value.
In short, no sane person should even consider using air core coils for this purpose. Just don't!
Air core coils in high frequency circuits is a big mistake though, and will most probably have the police knocking down your door, and thrown you in jail within hours of turning it on.
And even if you can somehow manage to fully shield those (which is pretty near impossible) air coils are good in low frequency circuits, especially speaker crossovers where core saturation will vary a lot and take time to build up, whereas in high frequency circuits core saturation is something that is near constant and near instant, and therefore calculated into the value.
In short, no sane person should even consider using air core coils for this purpose. Just don't!
DIY teflon over foil air cores
. Not exactly the glowing recommendation that I was hoping for. I guess every manufacturer of Tripath amps winds there own inductors as there seems to be no ready made coil for this application. I can't wait to try my new self made teflon over foil air cores. The parts should arrive from McMaster-Carr tomorrow so I can wind them up as soon as I get back from running with my scissors.
That's news to me...I've been using air-wound coils in ham radio gear for 45 years and neither the police or FCC have ever paid a visit.
So? As far as I know ham radios aren't "that purpose", meaning output filter coils on class D amplifiers. Many of which work around 300KHz switching frequency which means puts it smack bang in the middle of the maritime and aeronautic radio frequency range. Having an effective noise transmitter of up to several hundred watts in this range absolutely will land you in jail, or at least will get you a hefty fine.
Maybe you can find some surplus on e-bay from those manufacturers since let's face it, it isn't terribly costly to order even small quantities of special toroids. Compared to the cost of the toroid manufacturers needing to keep a stock of every possible value.
Anyone knows where to get the Ferroxcube gapped toroids on the net???
Have tried to serch, but without result .....
I've also tried without any luck.
I guess the next step would be to contact Ferroxcube directly; I just haven't gotten around to it.
Coilcraft sells a good 10uH type 2 iron powder toroid meant for PWM amps. The type 2 cores will be very good for an output LC filter, the other proprietary cores (like the low loss) are really meant for DC/DC converters. Type 2 will have much better frequency and DC current characteristics. I think the Coilcraft part is ED0006-AL and they will send free samples.
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Hi, I looked at the Micrometals site and for the RF mix core loss chart, the type -6 material seems to have a lower core loss then type -2 for the same frequence (eg looking at the 500kz), so is the -6 better than -2 for class D application seem both are for RF (or am I reading the chart incorrectly?)
http://www.micrometals.com/images/curves/RFCL6.html
http://www.micrometals.com/images/curves/RFCL2.html
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