Do you need a power line filter?

[FilipŠebík]

Hey, I just built this tesla coil http://kaizerpowerelectronics.dk/tesla-coils/kaizer-sstc-ii/ and I only powered it from 12V which gave me no sparks at all, just to tune it. Now I want to know if I need a line filter to power the primary from a transformer or mains and what would happen if I didn't use it. Thanks for the help

[Mads Barnkob]

Hi Filip and welcome to HVF!

For small coils like my SSTC's and the DRSSTC2, I would use mains filters that you can salvage from various consumer electronics.

When we start talking larger Tesla coils I have run them without, but that is also outside of buildings with a dedicated RF ground.

We do like to prevent as much noise as possible to run backwards into the mains supply, to protect the other electronic equipment in your house. The most important part of the line filter in regard to Tesla coils is the Y capacitors as they couple the line and neutral to the ground, around 10 nF is suitable if you are building it yourself.

[FilipŠebík]

So I can use ATX power supply filter? If that's it, then thanks

EDIT: Should I use it on mains input to transformer or low voltage transformer output?

[Mads Barnkob]

So I can use ATX power supply filter? If that's it, then thanks

EDIT: Should I use it on mains input to transformer or low voltage transformer output?

Yes you can use one from a ATX power supply, if it is rated for a high enough current. The filter should always be used on the mains supply side, so that would be the primary side of your transformer.

[FilipŠebík]

Nice, thanks for help