Class D Amp with LM566, LM393 and 2XIRF530

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#1,063
hi mr mile
i built irs1500 but my toroid iron powder heated after 15min
i think in d200 heated my toroid core
my core is t-106(yellow)
i did not find other core in my local city
can i turned wires coreless?(on the air)

respectfully
 
Last edited:
#1,066
behrad said:
hi mr mile
i built irs1500 but my toroid iron powder heated after 15min
i think in d200 heated my toroid core
my core is t-106(yellow)
i did not find other core in my local city
can i turned wires coreless?(on the air)

respectfully
Click to expand...

A city with only 1 type of core available? Impossible! You surely can get an old PC PSU. There is a big ferrite core (EE or EI) in it. With about 2 mm air gap it is much better than the crappy yellow iron powder, or air cored inductor.

Or you can use the core of the High Voltage trafo of any CRT TV or monitor. Etc... there must be some tons of it in any town for free.

Air core is OK for high power only if you use litze wire or you make it very big.
 
#1,069
stewin said:
how many turns to get 50uh . and what size of gap is needed sir ??
Click to expand...

Approximately L=n*A/h*mu0

A is the core cross-section, h is gap height, mu0 is permeability of vacuum (0.00000125). Everything is in SI unit.

BUT:
You must define saturation current requirement!

Approximately Isat=h*250(A/mm)/n

For example A=200mm^2, 1 mm gap height, 14 turn is about 50 uH, with Isat=17 A.

For 30 A you need h=3 mm and 25 turns, but this gap height has a relatively strong fringing flux, wires have to be kept away from it.
 
#1,070
Pafi said:
Approximately L=n*A/h*mu0

A is the core cross-section, h is gap height, mu0 is permeability of vacuum (0.00000125). Everything is in SI unit.

BUT:
You must define saturation current requirement!

Approximately Isat=h*250(A/mm)/n

For example A=200mm^2, 1 mm gap height, 14 turn is about 50 uH, with Isat=17 A.

For 30 A you need h=3 mm and 25 turns, but this gap height has a relatively strong fringing flux, wires have to be kept away from it.
Click to expand...



thanks paffi
 
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