Best 12uH output inductor for Tripath from Mouser?

[infinia]

Hi
1)This is a standard product that exceeds your requirements check for something else closer to what you want.
http://www.coilcraft.com/ed0006.cfm
instant pricing http://www.coilcraft.com/forms/quoteRequest.cfm

2) Contact a sales and/or get a second source price from a custom winding house (build to print).

3) Stay away from dogbone or other solenoid designs. Some center gapped cores probably are best regarding RFI/EMI concerns.

 

[theAnonymous1]

Hi
1)This is a standard product that exceeds your requirements check for something else closer to what you want.
http://www.coilcraft.com/ed0006.cfm

Again, this is a 20uH inductor. The OP wanted an off-the-shelf ~12uF inductor.

 

[infinia]

Again, this is a 20uH inductor. The OP wanted an off-the-shelf ~12uF inductor.

I said it exceeds his needs, but he needs to do some leg work too. I just threw that out there as an example I found in 3 min. I'm sure if contacted the sales guy he will be in.

He should re design the filter to accomodate a more standard initial inductor value, me thinks... slightly higher L works better anyhow. YMMV

 

[Saturnus]

I said it exceeds his needs, but he needs to do some leg work too. I just threw that out there as an example I found in 3 min. I'm sure if contacted the sales guy he will be in.

He should re design the filter to accomodate a more standard initial inductor value, me thinks... slightly higher L works better anyhow. YMMV

It was a replacement on a specific design

 

[speakerguy79]

I would still use type 2, it is what I see most commercial high power amps using. And unwinding the 20uH Coilcraft inductor to 12uH should be very easy.

 

[infinia]

It was a replacement on a specific design

I didn't think so, since fit, form, and function where not clearly stated. Besides inductance is variable depending on core and winding specifics along with operating conditions, so the initial value is just a stick in the ground for folks (designers) that know the score.

Besides what's so sacred with 12uH anyway? What's wrong with altering the shunt cap to keep the same LPF corner frequency being careful of Q from peaking too much with light loads.

 

[Baldin]

You can buy Micrometals cores here:
http://www.kitsandparts.com/

I have used the T106-2 for some design, seems to have good specs for up to 20uH
http://toroids.info/T106-2.php
These cores are only 1$ each + shipping

Download the design program from Micrometals to get your number of tursn etc.
http://www.micrometals.com/software_index.html

It's not at all dificult to wind the coils your self, as long as it's not for a production

Think you can use the T106-2 core for up to more then 200W

 

[ChuckT]

That's true, but you need more wire, and you will have more AC and/or DC loss in wire. You can get good result if you use a thick litz wire to wind the choke, the litz stucture lowers AC loss in wire, and the thickness lowers the DC loss.

Thanks for the reply.

perm -2 is 10, perm -6 is 8.5

If use T106,
for 11uH, -2 needs 27 turns, -6 needs 29 turns.
for 20uH, -2 need 36 turns, -6 needs 39 turns.
There is a few turns difference, so would the AC loss be significant vs the core loss gain?

I know most t-amp uses the -2, but -6 is a bit more expensive, maybe that is why the -2 is always used.

 

[Pafi]

so would the AC loss be significant vs the core loss gain?

It depends on the wire type and thickness.

 

[ChuckT]

Yes, but assuming all things equal, would -2 or -6 be a better choice for t-amps? Or the difference is insignificant?

I had some high flux type size T106 with perm 125u.
With 9 turns for around 11uH, it gets really hot even at idle, so I am looking for some that runs cool.

 

[Pafi]

I repeat: it depends on the wire type and thickness. With litz wire the -6 is better, with thick solid wire the proximity effect will induce more current in the wire with -6, but I can't calculate the exact values.

 

[ChuckT]

Oh I see. Sorry I didn't get that before. Thanks.

 

[sendler]

12 uH is the most common size

I have looked at several filter designs for various people's class D amps and nobody uses 20uH. All are based on coils of 11 or 12uH although some that use small gauge surface mount coils start with 22uH and let them droop to 12uH under power but the sonics are hampered with these tiny bobbin types.
.
Still desperately seeking that elusive part number. I would hope to approach the sound quality of my self made air cores with a toroid which won't pollute the universe with nasty noise. My air cores are audible in an AM radio up to 20 feet away but do sound unbelievably good, finally surpassing the sound of my long time reference class AB amp.
http://www.diyaudio.com/forums/showthread.php?p=1935648
This coil is the most critical part of a class D amp and deserves the best.

 

[sendler]

Half of 12

Actually now that I think of it, since I am stuck winding my own anyway, I will experiment to find the lowest value that can be used and still get decent suppression. I'm sure I will end up with something much less than 12 rather than more. I ordered some 106-2 and 130-2 toroids today and will also try winding some teflon over foil air cores as a reference. I am listening to a filter with 3.8uH air cores now and the sound is absolutely explosive, detailed and musical.