Shop Notes 10/18 - Tesla Coil rewind

Working on an authentic Tesla Coil (99.9% of the ones you see online are technically induction coils, not true Tesla coils.  They lack the 'extra' coil required for magnification.

Yesterday was spent buiding+winding an Extra coil, but unfortunately the calculated frequency was way too off (1mhz vs 1.9mhz predicted), so rather than tear apart the coil I decided to make another.

Luckily I had just enough plastic to fabricate one more, which went a bit faster than yesterday now that I kinda know what I'm doing.

More winding.   And winding.  And winding.  And winding.

60-some odd turns later it's done.  Now time to see what frequency it operates at...

Eric Dollard had some good notes for tat

Survey says, ~2.1mhz to 1.9mhz depending on loading.  Q factor between 110 and 130..

Almost perfect this time🥰

FYI for the Extra coil, it's better to be a bit over, so you can correct with loading.  For Secondaries, it's better to be a bit under, so you can trim the wires back.

Finally finished and staging for initial tuning (again)

The secondary needs to be trimmed back still, but just on this rough setup with a function generator it's magnifying 5v to about 170v, which puts it at a magnification factor of 34 without tuning.

One thing interesting about these things is how much energy is stored in the dielectric field.  Just moving your hand or touching a metal table are enough to throw off the tuning by several kilocycles.

That's it for today.

There are a lot of variables to tune in a proper Tesla coil so it will probably be a few days before I get it singing, then I can integrate the HV power supply and we'll see how it starts singing with a few hundred watts going through it.  Then I can start doing some of the more sci-fi tier experiments like FTL communications and power-through the earth.

Hope you enjoyed🤠