Hey guys, I‘m back. Today, we’re going to make a mini spark gap tesla coil that runs off of DC and can make sparks up to 2.5cm or an inch long. The best part is that it doesn’t involve any dangerous current and can even be considered portable.Tesla Coils are basically resonant transformers.The primary coil inducts an electromagnetic field into the secondary coil at the right frequency and it resonates to make the voltage jump higher.And again. *ALWAYS READ EVERYTHING BEFORE STARTING* Let’s jump right in shall we?

Supplies

Power supply: 11.1v Li-Po battery, 30kv voltage multiplier, heat shrink tubing, switch. Secondary coil: PVC pipe (8cm height, and around 7-7.6cm diameter), a lot of 30AWG wire (I bought a pound of it, but that’s way too much, although it is useful for other projects), a bottle of polyurethane varnish, a heat source to dry it quicker,A brush. Primary coil:12 AWG wire with thick insulation. Connections: A lot of alligator clips (13-14 should be enough but get a pack of twenty to be sure) Capacitors: Airtight Plastic containers(3) , Long metal rods (3) ( I used spoons), Aluminum foil tape, Water, Salt. Other: Wire stripper and cutter, electrical tape, two large nuts and bolts, cardboard stand. Optional: Topload (something round and conductive will do the job(make sure it can sit ontop), LOTS OF PATIENCE

Step 1: Power Supply

*MAKE SURE YOU DON’T SHORT THE BATTERY OR IT WILL EXPLODE OR CATCH ON FIRE*.Get your Li-Po battery and snip off the connector CAREFULLY making sure not to let the cutters short the battery. Then get three pieces of 1.5 inch or 3cm long heat shrink tubes and slide two of them them over the black and red wires of the battery, connect one end of the switch to the positive(red) side of the battery then slide a heat shrink tube over the red wire of the voltage multiplier. Connect the red wire of the voltage multiplier to the other side of the switch and slip the tubes over their connections. Finally, connect the black wire of the battery to the black wire of the voltage multiplier and slide the tube over the connection. Then you can shrink the tubes with your heat source. You can then test it out.

Step 2: Electric Boogaloo, Just Kidding. Secondary Coil

This is the most difficult part of this build as it requires patience and a bit of time. To make this easier, get a pole to act as a holder for the wire roll so you can make some sort of manual lathe. Get your PVC pipe and at around 0.4cm from the bottom, tape the 30 gauge wire and leave 5-6cm of wire extra at the bottom. Then, start winding, make sure you don’t leave any wide gaps and try not to kink or break the wire. Make sure you tape your progress otherwise if you mess up it will all unwind. It may take an hour or two but once you reach at around 0.4cm from the edge, tape it off, making sure to leave 5-6cm extra. After all this, you can start applying coats of varnish to the coil, you can use a hairdryer or heater to speed up this process. Apply around 10-20 coats. Then, to make it look more presentable, tape around the bottom of the coil.

Step 3: Primary

Get your 12 gauge wire and wind it around the secondary coil 12 times, then you can remove it from the secondary. Make sure you leave 4-5 cm of wire extra on both sides and strip about a cm of insulation off the edges. Bend them both in the same direction.You’ll have a loose coil, compress it and use tape to keep it in place.Use the photo above as reference.

Step 4: Capacitors

Get your cylindrical airtight containers and wrap them in aluminum foil tape, after that, fill them up 4/5 of the way with water.Sprinkle 5-6 pinches of salt into each container and mix.Put the spoons into each container.To connect the in series, use the photo above as reference.(Connect foil to foil, spoon to spoon.)I used alligator clips for easy connections.

Step 5: Base and Spark Gap

I used a cardboard lid as a temporary base for my coil, just tape some aluminum foil tape underneath it As a counter poise or ground and make sure you leave some extra as an electrode for the ground wires.
For the spark gap, i just used two nuts and bolts taped to whatever surface you want.

Step 6: Connections

Use this schematic to connect everything together.
You can also switch the spark gap and capacitor’s places.

Step 7: Topload?

For the top-load, I just used a jar cap covered with aluminum foil tape as a temporary solution.

Step 8: FINISHED!

*please excuse this rough and unrefined instructable, I did not have enough time to give it much pizzazz* Congratulations, If I wrote this right and you followed it right, Then you now have a functioning tesla coil.You can make it light up things wirelessly and a bunch of other experiments.You can put a hex nut on it with a steel sphere or a needle in the dark to see the full corona discharge.To make it portable, remove the major connections, and disassemble it, for the capacitors. Just screw on their lids and you’ll be ready to go.This was a fun project and I hope you guys enjoyed it too.