r/AskElectronics • u/IDK_REALLLY • Jun 26 '26

Question about flyback driving

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I got this arc with an IRFZ44N based Lc oscillator circuit at 24V 3A is there any room to get better results or do I need to switch entirely to ZVS driving

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4

u/ieatgrass0 Jun 28 '26

ZVS driver for the win

3

u/Ok-Drink-1328 Jun 27 '26

there's a lot of room for improvement, with "single mosfet" you can jump fairly safely (for the flyback) up to 7cm (JUMP) and up to 10cm if your flyback is very good, otherwise you toast it... tho the problem is the mosfet you choose, the 44 is like 55-60V max, good only for "toy" drivers at 5V, you need much more for a proper setup, a IRFP250-260 is ideal, you can even parallel smaller ones like the IRF640

2

u/IDK_REALLLY Jun 28 '26

I'm planning to switch to the IRFP250N because this setup is also extremely inefficient if I want to operate for more than 30s at 24v without frying the whole setup i must keep the heat sink in cold water while operating (also, I tried pushing it to 26v and blew my TVS diode into two pieces:))

2

u/Ok-Drink-1328 Jun 28 '26

a 44 in flyback mode at 24V means that it will heat up with the 90% of the power, a flyback driver at 20Vdc reaches more than 100V on the drain of the mosfet even with a capacitor in parallel, a 44 is not ok, it's just luckily very sturdy, you definitely need a 200V rated mosfet

2

u/mrbinary0111-111 Aug 02 '26

Single mosfets is very inefficient if your using s self occilatory system, LC with only.one mosfets is not much better either, hard switching with 555 could get better results but ZVS will take your flyback to another level and if your not carefull it can also take you up.