diy High voltage ignition coil

[tazea]

Hi, ive been playing around with high voltage and i came around this type of transformers, looking more like an ignition coil and Im trying to replicate it, but im getting hardly any arc now, i did the first time i wired it (probably 15mm arc) but then it just didnt work anymore. I wired it like a ignition coil (connected both secondary and primary ground to mosfet drain) to my 555 timer driver circuit, with push pull configuration driving a IRFP240 MOSFET. But i had to reverse the connection because i was seeing some weird interference in my pc monitor. Also the first time i tested it, it draw from 1.5 to 2.5A from my 12v power supply, but now when i turn it on the power supply cant stand the current draw, its drawing like 4 to 6A of current which i found strange too. Maybe i damaged my driver?

This is the type of transformer im trying to replicate:


my bobbin:


it consist of 20 turns of 0.5mm wire on primary and 6400 turns of 0.08 wire on secondary side.

later on the plan is to attach a cockroft walton voltage multiplier like this:



Thank you everyone in advance.. and sorry for my little knowledge

[davekni]

Probably a wire insulation failure of secondary winding, most likely where wire transitions from one segment to the next.

[ZakW]

Hey Tazea,

Check out my post here https://highvoltageforum.net/index.php?topic=2667.0. Like Dave mentioned, I had a failure in that exact spot (circled in blue in the picture). I fixed the issue by adding a second section in between the coils so the wire starts at the bottom and not from the top.

[tazea]

Hi, thank you so much for your replies, ive thought about that but the coil is insulated with epoxy so i just wanted it to be something else. Ill try to follow your advice ZakW