Hi I'm looking to wind my own choke coils to replace the ones on my helder 2024 amp and I'm wondering how many turns and what size ferret core I would need to create a 10uh 3A 3mhz coil. I tried using a calculator but I find it very confusing and I keep getting different results. I would like to make them identical to the ones in the link below. Any help would be greatly appreciated. Thanks
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Ah, that explains it.
Anyway to answer the question, a medium size ferret (one to one and a half kilograms) should be fine, with 10 turns of wire around it, stretched to a length of about 6 inches. The coil, that is, not the ferret. Under no circumstances should you attempt to stretch the ferret.
Anyway to answer the question, a medium size ferret (one to one and a half kilograms) should be fine, with 10 turns of wire around it, stretched to a length of about 6 inches. The coil, that is, not the ferret. Under no circumstances should you attempt to stretch the ferret.
From the picture, I counted about 38 turns on those eBay coils. But my eyesight's poor...
Working backwards then, the AL value to get to 10uH must be 7nH
Looking down this table -Iron Powder Toroidal Cores For Power Conversion and Line Filter Applications : CWS ByteMark, largest supplier of toroids, ferrite cores, iron powder cores, MPP cores and RF cores
it seems a 0.9" diameter core of type 2 material fits the bill, its AL is 8.4. Meaning you should wind on 35turns to get 10uH, or 51 turns if you want 22uH (for an 8 ohm speaker).
Working backwards then, the AL value to get to 10uH must be 7nH
Looking down this table -Iron Powder Toroidal Cores For Power Conversion and Line Filter Applications : CWS ByteMark, largest supplier of toroids, ferrite cores, iron powder cores, MPP cores and RF cores
it seems a 0.9" diameter core of type 2 material fits the bill, its AL is 8.4. Meaning you should wind on 35turns to get 10uH, or 51 turns if you want 22uH (for an 8 ohm speaker).
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