Solid State Tesla Coil/High Voltage Generator

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This is a fun and useful circuit for demonstrating high frequency high voltge. It can produce up to about 30KV, depending on the transformer used. It is cheap and easy to make, thanks to the standard TV flyback transformer used. It can power LASERS (although I have never tried), demonstrate St.Elmo's fire, and even cause a fluorescent bulb to light from as much as 2 feet away.



This is the schematic of the solid state tesla coil/high voltage generator


Total Qty.
R1127 Ohm 5W Resistor27 Ohm 10W Resistor
R21240 Ohm 5W Resistor240 Ohm 10W Resistor
BR1150 Volt, 6 Amp Bridge Rectifier
C118000uf, 35 Volt Capacitor
Q1, Q222N3055 NPN Power Transistor
T1124V 5A Transformer (See "Notes")
T21TV Flyback Transformer (See "Notes")
S11115V 3A SPST Switch
MISC1Case, Wire, Heatsinks, Line Cord


  1. T2 is a high voltage flyback transformer salvaged from an old TV, or ordered from Fair Radio Sales (see Where To Get Parts). Look for the biggest, most intimidating transformer you can find. Old tube TV's are a good place to look. The transformer should not have a rectifier built in.
  2. You will need to rewind the transformer's primary. First, remove the old primary, being careful not to damage the high voltage secondary. If the transformer is wound with all windings incased in plastic, use another transformer. Second, wind on 5 turns of 18 AWG wire, twist a loop (center tap), and then wind on 5 more turns. This becomes winding C-D. Now, wind on 2 turns of 22 AWG wire, twist a loop, and wind on 2 more turns. This becomes winding A-B.
  3. Q1 and Q2 will run HOT if not used with a large heatsink. After the circuit has been running for a minute or two, you should still be able to put your finger on the transistors without being burnt. Also, R1 and R2 will run hot.
  4. If you experience arcing on the exposed transformer leads, select a lower voltage for T1. If you are powering the circuit with a power supply (see Power Supply), just crank down the voltage.
  5. For a real high voltage output, connect a voltage multiplier (from an old TV or computer monitor) to the output of T2.
  6. If the circuit does not work, reverse connections A and B.
  7. I finally got around to taking some pictures of the circuit in operation. Here they are:

    Arc from generator without voltage multiplierArc from generator with voltage multiplier

    The first picture is the high voltage generator without the voltage multiplier. Notice how hot the arc looks. The second picture is the high voltage generator with a voltage multiplier installed. Notice how much brighter the arc is.

    Me charged with high voltage holding a glowing light bulbMe charged with high voltage holding a glowing light bulbMe charged with high voltage holding a glowing light bulb

    The above pictures of myself were taken with me standing on an pie plate that was resting on the top of a plastic bucket. The pie plate was connected to the high voltage generator and charged to about 40,000V. If you do this, be sure to have someone else turn on and off the high voltage generator. Also, don't touch anything when you are charged. Have everything you are going to hold/play with already sitting on the bucket and away from grounded objects. Remember to take off your watch...

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Solid State Tesla Coil/High Voltage Generator
Friday, July 15, 2016 8:59:44 PM
About a month ago I read where someone was using a stun gun to launch potatoes. Well I got on ebay and purchased one for about $5.00. I've tried it out on several spud guns and it works quite well. Was Actually cheaper than a $6.00 lantern igniter. Spark is much thicker and goes further than one of those Piezo igniters. It also comes with a rechargeable battery! Lookup Viper stun guns on ebay, I think you'll be surprised at how cheaply you can get them! Dave
Solid State Tesla Coil/High Voltage Generator
Tuesday, December 04, 2012 8:35:24 AM
Can this light my house free electricity?

(Editor's notes: Yes, of course.)

Solid State Tesla Coil/High Voltage Generator
Thursday, April 07, 2011 4:00:07 PM
I have been reading the comments and just wanted to add that this circuit does create a hi frequency resonance. This is caused by the switching times being set by the saturation of P1 (A,B). this means that once the circuit starts, It allows the power to flow through the primary in one direction (we will assume Q1 switches on the first time as this is down to very tiny differences in the transistors as to which one starts). The flow will the switch the other way as the base of Q2 exceeds 0.6V. at the same time as doing this, the voltage at the base of Q1 is continues to fall to the switch off point. This works because both the primary and P1 are centre tapped, with the centre being ground. A couple of things to make note of are.... Always us an AC flyback transformer not a new DC type. Make sure your flyback is ferrite cored and is gapped as this is what helps to set up the resonance. And lastly, If you add a spark gap to the secondary output, the circuit becomes safe to use even when your grounded as high frequency, high voltage with ultra low amps is the only thing that can pass the gap.
Brian Drake
need help on getting high freqency for TIG welder
Friday, February 11, 2011 11:15:58 AM
I have made a arc welder from microwave transformers that works very well. I would like to add the ability to tig weld. I have all the required equipment to TIG weld (argon/CO2, hoses,cable, tig torch, tungsten,ect.) except for the high frequency AC voltage that would normally be provided by the welding unit. If anyone has any input on how to add a high frequency AC mode to the homemade welder please let me know.
Not High Frequency
Thursday, June 17, 2010 11:42:29 AM
This circuit looks good, but I think its incorrect to claim it as "high frequency". It appears that it runs at 60Hz AC. This is incredibly LOW frequency for a tesla coil. The point of the coil is to create a resonant effect. To do this, you need very high frequency that matches the resonance of the coil. Also, this circuit is very dangerous because the pulse durations are so long. A super high frequency circuit with very short duty cycle (Pulse ON time of less than 50 microseconds) is much safer and will even be far more powerful. I recommend reading Tesla's patents and studying other info on Tesla coils. Nonetheless, great work and thanks for sharing!! :)

(Editor's notes: The circuit doesn't run at 60Hz. Its frequency is mainly set by the characteristics of the transistors and the primaries of the flyback. Flyback transformers don't even work at 60Hz.)

Solid State Tesla Coil/High Voltage Generator
Saturday, February 20, 2010 11:35:49 AM
Does anybody know, where to get already done product to buy like for example:I would like to have something like input: 3V - 12V output 500V - 1kV. I dont know even where to look, I was looking on google I couldnt find even one product.
Solid State Tesla Coil/High Voltage Generator
Wednesday, February 17, 2010 2:54:28 AM
what is the voltage input to T1 and what is the output voltage of T1 and what is the input voltage to T2
Solid State Tesla Coil/High Voltage Generator
Tuesday, December 15, 2009 9:44:14 AM
i've made a ps with fly trnsformer,and it works but... what should i do with the other pins? sometimes spark occured between them. especialy some closest pins with ground pin. one of pin closest is also draws purple spray, but never spark
Solid State Tesla Coil/High Voltage Generator
Sunday, September 13, 2009 6:01:45 AM
ZVS inverter or mazzilli inverter is the best flyback driver using IRFP250
Solid State Tesla Coil/High Voltage Generator
Wednesday, July 29, 2009 6:15:43 AM
ahem... you say "remember to take your watch off.." but I can clearly see that YOUR watch is still on!!! Any experience you wanna share :) ?
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