Tesla Coil help

Thread Starter


Joined Feb 17, 2009
I'm working on building a Tesla Coil and I wanted to measure it's actual output voltage from the secondary.

This seems like a really dumb question, frankly I'm embarrassed to ask, but are there voltage limits on resistors?

My thought was that I can build a voltage divider and connect it to the end of my secondary and use my multimeter to measure the voltage. But if it's around 15,000V I'm going to need really big resistors. What else can I do to measure the voltage? Turn ratios for an air core don't seem to be appropriate.

this is what I'm building:


Joined Sep 20, 2005
I read you can use a string of high value resistors, like 20x 1Mohm. As this will probably cause arcing over each of the resistors, they immersed the whole string in a tube filled with insulating oil.

Be careful not to get over the insulating capability of the oil, because then the current through the oil could make it boil and then burn.