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Electronics => Electronics => Topic started by: aruna1 on April 28, 2012, 05:32:06 AM

Title: SMPS inductor question
Post by: aruna1 on April 28, 2012, 05:32:06 AM
Can some one please tell me what are the advantages and disadvantages of using a toroid inductor(hand made) for the inductor of buck or boost converter?
(http://www.coilws.com/images/custom_wind-products/toroidal-choke-ip.jpg)

Or is inductor in a buck or boost converter must be a one like these?

(http://www.isplc2006.org/b2b/pics/Shielded_SMD_Power_Inductors.jpg)

thank you
Title: Re: SMPS inductor question
Post by: Soeren on April 28, 2012, 11:46:01 AM
Hi,

Can some one please tell me what are the advantages and disadvantages of using a toroid inductor(hand made) for the inductor of buck or boost converter?
Both kinds will work (but select the grade/material for the purpose and frequency).

A few examples of the pros and cons...

Toroid:
Advantages: Cheap to produce. Magnetic field closed in he core.
Disadvantages: Laborious to wind. If material and frequency isn't carefully selected, you risk core saturation (which is bad)

Pot cores and similar:
Advantages: Can be had with an air gap (or be gapped with paper/plastic sheet to avoid saturation - some gapped cores have an adjustment screw to fine tune the gap). Easy to wind (hence cheaper and easily automated). Comes in various shapes and in lots of different AL values.
Disadvantages: Price. Comes in two or more parts that need to be held togeth with special clips or glue.

In your photo #2, There's one pot core (middle one in the top row). Middle row leftmost is a "pigs snout" used for RF transformers and right under that is something I cannot determine; either a licorice with a pin through the middle, or a ready wound coil maybe ;)
The rest of them seems to be nothing but shielded versions of otherwise open cores.

The above is not preemptive, but since it's your school work, I should leave a little to you ;D
Title: Re: SMPS inductor question
Post by: aruna1 on April 28, 2012, 12:12:40 PM
Thank you very much soren ;D

Quote
The above is not preemptive, but since it's your school work, I should leave a little to you

lolz its not home work. i was used to build smps with toroid inductors and few days back a man (who has more experience than me) told me toroid cores are not for SMPS as they cant deliver much current. for SMPS you should go with something with air gap, that is why i need to clarify the thing :o