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Thread: Chokes, for DC->DC power supplies

  1. #1
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    Chokes, for DC->DC power supplies

    Hello there.

    Does any one has/know of any programs that i can use to make chokes for DC converter.

    Or does any one know specifications for making 50mH chokes with 6 amps handling.

    Fosgate
    Fosgate

    System Comp V3 - In progress.
    Low power MB with C7 CPU, DC-DC PSU, car ECU link, USB TV, GPS, 7" TFT, Wireless, Voice.

  2. #2
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    Really depends on the core you use (the magnetic permeability). The number of turns depends on the core material and size of the core.

    I see you are asking for 50mH at 6 amps. Maxim chips? Pull the data sheet on the 724 part and you'll see that this 50uH (micro not milli) is not critical.

    Go buy these $2.99 inductors from All Electronics is Los Angeles. 100uH at 9Amps. They'll work fine.

    Wouldn't you know it, I can't find my flyer from them. Call them up and ask them about it. Much cheaper than buying the 50uH 9A ones from Mouser or Digikey.


  3. #3
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    Hello there Probedude_2000.

    Thanks for the replay.

    Well im living in Australia and to get parts from US usualy cost more for the shipment then the part it self . On the other hand i can make those chokes my self as i got all the parts for it such as different size wires, many types of ferrit rods and so on. Also as i work in the Telecomunication company we got all the right equipment to mesure the indactance with very high accuracy ( i guess we dont really need that accuret). So its just i need to start from somewhere, i need to know what type of wire and ferrit to use so then bit of trial and error will get me to the value i need.

    Well you recon... where can i start?

    Fosgate
    Fosgate

    System Comp V3 - In progress.
    Low power MB with C7 CPU, DC-DC PSU, car ECU link, USB TV, GPS, 7" TFT, Wireless, Voice.

  4. #4
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    For the wire size required use a current density of 5 A per square mm for copper in still air. You could raise the density to 7A per square mm for copper in forced air cooling. Thus, wire of 1.3mm(16 AWG) diameter should adequate or two parallel strands of 0.9mm(19 AWG).

    A toriodal ferrite core of outside diameter 20-30mm should be sufficient without saturation. I don't know what permeability cores you have available so I would guess 30-40 turns of wire should give close to 50uH inductance. Use your inductance meter to set the value exactly.

  5. #5
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    Sproggy thanks alot for the information.

    I will surly do that today and will test it tomorrow on the meter. I will let you know how it goes.

    Thanks guys!

    Fosgate
    Fosgate

    System Comp V3 - In progress.
    Low power MB with C7 CPU, DC-DC PSU, car ECU link, USB TV, GPS, 7" TFT, Wireless, Voice.

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