Kool Mu core chokes for the class D output chokes?

[rhythmsandy]

Im planning to build an IRS2092 amp and wanted to know about the Kool Mu cores for the output choke. Can anyone tell me that is it excellent core for both quality and transient power transfer is good in that?

 

[abraxalito]

I believe Kool Mu is pretty much the same as Sendust. Can't help feeling its going to be rather lossy compared to a gapped ferrite core.

 

[rhythmsandy]

Magnetics - Large Kool Mu Core Shapes

Just have a look at the comparison with various core materials.

you can check this thread where its mentioned as powdered iron cores getting hot at 400KHz
Amidon T200-2 core suitability for 1kWrms?

 

[rhythmsandy]

I believe Kool Mu is pretty much the same as Sendust. Can't help feeling its going to be rather lossy compared to a gapped ferrite core.

how much % lossy?
on the site it states that Kool Mu has lower losses than Powder iron core.
Magnetics - Kool Mu and Powdered Iron Comparison

 

[abraxalito]

Here are the plots for losses vs frequency from Ferroxcube. You'll be operating between 300 and 500kHz typically for classD audio. I'm seeing around 6W/cc @0.1T.

 

[theAnonymous1]

A few years ago I wanted to get some Ferroxcube TN26/11-3C20-A113 gapped toroids but couldn't find anywhere to buy them in small quantities.

http://ferroxcube.home.pl/appl/info/class D audio amplifier.pdf

 

[rhythmsandy]

I have accessibility for the Kool Mu cores from Maginc so as per the specs wouldn't that help?

 

[rhythmsandy]

Can anyone confirm me as I see the core losses in higher frequencies is less in this.

Generally for how much output power the wattage of the choke can be considered like

for 1000WRMS Class D amplifier so does it require 50W power handling choke? with heavier gauge wire.

 

[kartino]

MS157060 is commonly used for 1000W typical.
T157-2 will be better

 

[rafsky]

You can also use classic ETD ferrite (N87, N97 or similar) with appropriate gap, the winding length is usually less, so less copper dispersion, an ETD29 from my experiments was much better than 130.2 up to 0,5Kw

 

[darkfenriz]

I am happy with sendust based chokes for Arnold. They are extremely easy to use and will run cool-ish at up to 400kHz or more.

Mine is off-the-shelf rated 33uH at 8A and I believe is based on MS-080075.

That's good for, say 200W. For 1000W I'd look at MS-106075 (minimum) or preferably MS-130060.

Very accaptable EMI and HF behaviour.

High idiot proofness factor as permeability drops very gradually with DC bias, so the amp may be fine even with the lousiest short-circuit protection there is. This may not hold true for rapidly saturating ferrite cores.
The drawback is not so perfect linearity, unless you take care of it elsewhere (modulator, feedback etc.)

 

[rhythmsandy]

I am happy with sendust based chokes for Arnold. They are extremely easy to use and will run cool-ish at up to 400kHz or more.

Mine is off-the-shelf rated 33uH at 8A and I believe is based on MS-080075.

That's good for, say 200W. For 1000W I'd look at MS-106075 (minimum) or preferably MS-130060.

Very accaptable EMI and HF behaviour.

High idiot proofness factor as permeability drops very gradually with DC bias, so the amp may be fine even with the lousiest short-circuit protection there is. This may not hold true for rapidly saturating ferrite cores.
The drawback is not so perfect linearity, unless you take care of it elsewhere (modulator, feedback etc.)

so KoolMu should be a good choice then?
Which core to be chosen for 1000W in 4ohm usage. If you can suggest from the below link it will be very helpful.
Magnetics - Kool Mu Cores

 

[darkfenriz]

0077259A7 may be a good starting point