Tag Archives: coil

Monday night – coil

Today was so uneventful.. so pathologically bland .. that I can’t even think of anything to report.. I’m grateful  for days like that every once in a while.. but 2 or 3 in a row is more than I can’t stand..

I’ll fall back to reporting on soemthing I did yesterday (Judges.. can I do that ? )… Long time readers will remember that last year I set out to build a smaller, lighter weight Tesla coil for use in my shows. I got a generous grant form the local IEEE chapter to get it started. I chose a design being offered by a company that also provided both circuit boards and most of the components.. .. It turned out to be something of a nightmare getting the design to function, the circuit diagrams had errors and contradictions, . the parts  I received didn’t match the design. or were of poor quality.. .. but eventually.. by spring..  I was able to get the thing working. I was so excited that I took it to work to do a demo for some customers that were  visiting. The thing worked for a few seconds.. then a giant spark.. and then nothing. It had shocked itself to pieces.. most of the components inside were fried.. For months it st in the shop staring at me.. ut I didn’t have the stomach to do all the repair..   Finally my friend Scott offered to help.. he had a little spare time and much more patience for the thing than I had.. He took the device and rebuilt the damaged parts using new circuit boards and components.   He also cleaned up my less than perfect wiring layouts.. by August.. he had the coil working again.. but.. then.. disaster struck again.. it blew out the expensive output transistors… not once.. but twice.. and at $20 a pop.. that was no  fun..  Eventually, we throttled back the power.. and got the thing stable..   Instead of the 30+ inch spark I was gettign.. it was now limited to a pretty tame 20″ spark

Sunday mornign I was looking at the coil trying to figure out what I could do with a device with that relatively tame output specs.. then it occurred to me .. that it would be a perfect base for a musical coil.. I did a little bit of staring at the deign.. and figured out a pretty simple plan.. I wrote a small bit of code on an arduino microcontroller that converted telephone ringtones into square wave outputs.. then I cut one of the signal path in the tesla controllers modulator control. I stuck the audio signal into the input trigger of one of the modulator oscillators…

ant this is what I got..

Next step is to tune the output to get about twice this spark.. wish me luck !

nite all, nite sam
-me