Step 16: Operation


Follow the directions!


  The Tesla coil is a dangerous high voltage device. Used properly, it is an educational and fun electronics project that displays beautiful electrical arcs and lets you play with a unique form of sound creation. Used improperly, it can lead to serious injury. Always follow the directions!


Treat your energized Tesla coil the same way that you would treat an open flame. You wouldn’t leave a burning stove unattended, nor let a child access matches and kerosene, would you? Don’t leave your Tesla coil unattended or in a situation where a child or unqualified operator can access it.

  • Keep away from the coil while operating! Keep yourself, other people, and sensitive electronics a minimum distance of the length of the fiber optic cable apart from the Tesla coil. Persons with pacemakers or other medical implants should not be in the area.
  • Never touch the output of the Tesla coil! The sparks will burn you if you come in contact with them.
  • Always follow the startup and shutdown procedures when turning on and off your Tesla coil.
  • Note that the output of the Tesla coil can be very loud. Always start your coil on low power and ramp up slowly. Don’t run your coil in a location where the noise is irritating to other people!




  • The biggest issue to watch for is flashover on the secondary, or any arcing in places you don’t want it. Upon seeing unwanted arcing, stop operating immediately and fix the problem.
  • If you’re using a laptop to control your coil, it should be running off of its battery and be unplugged from its charger.
  • It’s not a good idea to draw arcs from the coil using metal objects or a fluorescent gas tube, particularly at high power. Arcs draw a lot of current and can stress the IGBTs. A fluorescent tube put next to the Tesla coil will light up!
  • To avoid failures due to overheating, don’t run your coil for more than a few minutes at a time. If doing an extended run, use your coil on half power or less. It will prolong its run time and spare you from a migraine!
  • To make your life a little easier, use a power strip with an on/off switch rather than using the cord to plug in and unplug your Tesla coil.


Patching burned spots on the coil

When you have arcing on your secondary, you compromise the insulation. The situation will not get any better if you ignore it! A hefty dollop of glue over the burned spot will mitigate the problem. The picture shows a successful repair job on a secondary that lasted a long time despite a small amount of arcing.

  How to patch a secondary



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