Tesla coils produce high frequency AC which is passed through a diode and capacitor to produce DC. This Tesla coil rectification is a difficult task as very high voltage diodes capable of running at several hundred kHz are not easy to come by.
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From the top of the Tesla coil is attached a string of 20 x 20 kV diodes rated at 10 mA and with a fast recovery of 100 ns.
So theoretically rated at 400 kV (if under oil and with various other precautions).
The diode attaches to a string of capacitors rated at 56 pF at 100 kV. Each ceramic cap is rated at 2.2 nF at 2.5 kV and there are 39 in the string.
Tesla coil rectification refers to the process of changing AC to DC.
The first diode in this string has corona all around it. Not sure if this first diode still works.
Tesla coil rectified with 3 inch spark across the diode. This is marginally longer than the usual AC Tesla coil spark. The 3 inch DC spark probably more closely represents the 30 kV per inch, i.e. approaching 90 kV total.
While this might be feasible in a small Tesla coil there are significant challenges in scaling this up to a full sized coil. A 90 inch spark (rather than 3 inch) would require many more diodes. It’s not clear how many since even a large Tesla coil is only 500 kV or so and hence would only need a theoretical minimum of diodes rated to 1000 kV. However, corona will cause increasingly large losses.
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Photo Date: Oct 11, 2012