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Solid States Devices => solid state devices => Topic started by: clone477 on August 18, 2009, 11:53:50 PM

Title: How to Measure output of Tesla coil
Post by: clone477 on August 18, 2009, 11:53:50 PM
Guys,
I was searching and trying to find a why to measure the output of a Tesla coils secondary.  The only way I found was measuring the length of the discharges, and that will give you a rough idea.  But can you use some type of resistance, such as incandesent bulbs wires in series, or maybe a resistive electric heater??  As far as I know resistive element should'nt be bothered by HF, or am I mistaken?  But what about the high voltage??  If you wire enough resistive loads in series that should handle the high voltage, but how many resistive loads?

Can anyone suggest a way to measure the output in watts?? 
Thanks Fern
Title: Re: How to Measure output of Tesla coil
Post by: onthecuttingedge2005 on August 19, 2009, 02:19:01 AM
Hi Clone.

3kV per mm at 0 sea level = 30kV per cm at 0 sea level.

Elevation and Dielectric constant of air and moister changes these variables, you can use a micrometer to make more accurate measurements.

Jerry ;)
Title: Re: How to Measure output of Tesla coil
Post by: flathunter on August 27, 2009, 02:48:58 PM
Hi guys!

I'm asking exactly the same question (how do i measure the output of a TC) on the other thread ''Tesla coils and CFLs''.

As I understand its very very difficult as the output is such high frequency.  I wouldnt even dream of putting a multimetre near it!  So any ideas from the brainy chaps here?  Come on...I know there are lots of you!  At the moment, im just trying to measure useful output - how many CFLs can I light from receiver coil connections?  I can light loads of CFLs, and even some diode bulbs.  I havent managed a filament light bulb.......yet..... ;)

Any suggestions?

???
Title: Re: How to Measure output of Tesla coil
Post by: xee2 on August 29, 2009, 02:40:12 PM
The main problem is that the output is pulsed. So there are very high voltage pulses with very low voltage between them. The way I measured the output of a flyback transformer was to make a 1000:1 resistive voltage divider. But of course the Tesla coil would need a 10,000:1 divider. Then I used a diode and capacitor to get the peak voltage. Once the peak voltage is know, then the peak power can be computed from volts squared divided by the divider resistance. To get the average power out, a scope would need to be loosely coupled (wire in air 10 feet away) and the duty factor of the pulses would need to be measured. Then the average power out of Tesla coil is peak power times duty factor. Complicated but it can be done (with great care for safety).

NOTE: multiple resistors are used so that the voltage drop across each resistor is low enough that a spark will not jump over it.