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laminated iron core DC high current filter choke vs. CT toroid

laminated iron core DC high current filter choke vs. CT toroid

laminated iron core DC high current filter choke vs. CT toroid

(OP)
Is it feasible to press a surplus current transformer (toroid type) into acceptable service as a DC power choke for 100 & 120 HZ
ripple?  I calculated a needed L of about 1.8 to 2milliH of L.  Any one had success doing something similar?
Thanks,
MikeHS

RE: laminated iron core DC high current filter choke vs. CT toroid

If you have a DC component then you will likely have saturation problems if you use an AC core unless you can introduce an airgap.
  

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If we learn from our mistakes I'm getting a great education!
 

RE: laminated iron core DC high current filter choke vs. CT toroid

about 1.8 to 2milliH of L

That seems rather low value.  Not a very critical application.  I've used low voltage transformer secondaries.

RE: laminated iron core DC high current filter choke vs. CT toroid

I agree to Scotty UK. But you should keep in mind that the main difference between a transformer and a choke is the airgap

- transformer --> no energy storage --> high µ material, no airgap
- choke --> energy storage --> airgap (or distributed airgap by using low µ material)

RE: laminated iron core DC high current filter choke vs. CT toroid

A current transformer (CT) will not make a good filter inductor. Most CT are designed using a core with moderately high permeability (u value). If the CT was intended for a frequency response to a few 10's of kHz, then the core is likely a ferrite - a very poor choice for low frequency where all the current is essentially magnetizing current, that is: low frequency AC current is equivalent to having a DC bias current and it takes very little to saturate a high u core.

Now, the core of a CT would be a good choice as a common mode choke, but the single high-turn winding of a CT is not suitable as the winding of a common mode choke.

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