Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
This is a good comparison, but initially I thought the mosfet that drives E-I core without airgap will be MORE HOT compared to the mosfet that drives the E-I core with airgap. But after thinking a while, your result is reasonable.rx5 said:ive compared an E-I core with and without airgap...ive noticed, the driving MOSFETS heats up a lot faster if an airgap is present, but with the GAP removed, little heating only?
Yes ... need extra ampere turn, which can be increased by increasing current or increasing the number of winding turn. In 'is_razi' case, number of winding turn should be increased (which will increase the inductance).rx5 said:you must offer an extra ampere turn for the air gap magnetization.
i think that the core wasn't saturated so for the ei core the air gap A.T is added to the core A.T and this increase the current.
if the core is saturated the mosfet can be destroyed.
rx5 said:here is the list,
1. E-I core, no GAP, no heat for Mosfet driver
2. E-I core, with GAP, heat from Mosfets
3. toriod 1.25" outer dia, MUCH heat from mosfets..
maybe (i think?) toroids have much magnetic coupling?? than the E-I cores?? i dunno... i even tried re rewinding the toroid and wraping it with a single layer of masking tape, just to make sure its (winding) is insulated from the ferrite core..
rx5 said:what do you propose i do so that i dont get the toriod into saturation region?? decrease magnet wire size?
My previous comments might not be correct in your situation. Let's discuss more.rx5 said:nicleo,
why would you suggest decrease winidng? a co-forumer of mine told me to in increase my 4T+4T into 6T+6T.. so as not to load much on the mosfets...
sorry, the only LARGEST toroid i could find is only 1.25"... i live in an "uncivilized" part of the earth where parts are hard to find...
nicleo said:My previous comments might not be correct in your situation. Let's discuss more.rx5 said:nicleo,
why would you suggest decrease winidng? a co-forumer of mine told me to in increase my 4T+4T into 6T+6T.. so as not to load much on the mosfets...
sorry, the only LARGEST toroid i could find is only 1.25"... i live in an "uncivilized" part of the earth where parts are hard to find...
1) How many number of winding turn that you wound on the toroidal core?
2) What is the Voltage across the winding?
3) What is the switching frequency of the mosfet?
4) Did the wound toroidal core get hot?
5) How many 1.25" toroidal you have?
Pls update.
Something to add:
Probably in your case, the toroidal core was not driven into saturation region yet. It's just simply that the number of turn was not enough to produce sufficient inductance to limit the current to normal level. Your co-forumer might be correct.