I have always been fascinated by Nikola Tesla's inventions and scientific discoveries. Recently, I wanted to build my own Tesla coil at home as a hobby project. Specifically, I wanted to build one powerful enough to zap fruit and turn it into juice!

Turning fruit into juice using electricity may seem dangerous at first. However, with proper precautions and materials, building your own fruit-zapping Tesla coil can be a fun and educational scientific experiment. In this article, I will provide a step-by-step guide on how I built my homemade Tesla coil from scratch and used it to zap fruit into juice.

Overview of a Tesla Coil

Before jumping into the building process, let's first go over what exactly a Tesla coil is and how it works.

A Tesla coil is an electrical resonant transformer circuit designed by Nikola Tesla in 1891. It consists of two parts - a primary coil and a secondary coil. The primary coil is connected to a high-voltage power source. When electricity passes through it, it induces a fluctuating magnetic field which causes the secondary coil to resonate at a specific frequency.

The resonance amplifies the voltage output tremendously, resulting in lightning-like electrical discharges that shoot out from the top of the secondary coil. This is what gives Tesla coils their distinctive arching sparks.

Parts Needed

Building a homemade Tesla coil from scratch requires various electronic components. Here are the main parts I used for my fruit-zapping Tesla coil project:

In addition to these main parts, various connecting wires, a sturdy base, and tools are required.

Step 1 - Wind the Primary Coil

The first step is to wind the primary coil. This coil is connected to the neon sign transformer to amplify the voltage. I wound my primary coil using 14AWG magnet wire in a flat pancake shape.

The completed primary coil should look like a flat spiral pancake shape with wire leads sticking out for connections.

Step 2 - Wind the Secondary Coil

The secondary coil resonates with the magnetic field from the primary coil and amplifies the voltage even further. Wind this coil using thinner 28AWG magnet wire.

I wound my secondary with approximately 900 turns of magnet wire around a 6 inch cardboard tube. This provides the resonance needed to step the voltage up to around 100,000 volts!

Step 3 - Connect Coil to Capacitors and Spark Gap

Now we need to connect the primary coil to the high voltage capacitors and spark gap:

Proper tuning of the capacitors and spark gap is critical for maximizing the power output to the coils.

Step 4 - Assemble Secondary Coil with Topload

Now we can assemble the secondary coil and "topload":

At this stage we have a complete Tesla coil ready to generate some big sparks!

Step 5 - Safety Checks and First Power Up

Before plugging in the Tesla coil, double check the following safety measures:

When ready, connect the neon sign transformer to the spark gap while standing at a safe distance. This will power up the Tesla coil. Adjust the spark gap and capacitors to tune the arc frequency and length.

Warning! Extremely dangerous high voltages are involved. Take precautions when operating a Tesla coil.

Zapping Fruit into Juice

Once the homemade Tesla coil is tuned and running safely, we can try out zapping fruit into juice!

Note: Always keep flammable materials away from a running Tesla coil. The high voltage discharges create ozone and can ignite fires.

With proper adjustments to the power and coil tuning, I was able to zap a wide variety of fruits into sweet and tangy juices! It's a really fun way to learn about electrical engineering principles hands-on.


Building a homemade Tesla coil capable of zapping fruit into juice was a really enjoyable electronics project that also looks awesome in action! With some careful planning and safety precautions, you can definitely DIY your own with components purchased online. Just be extremely careful when working with high voltage currents.

I encourage you to learn more about how Tesla coils work and the science behind them. Then put that knowledge to use building your own fruit-zapping coil or other creative designs! With the right know-how you can harness high power electrical discharges to do all kinds of unique experiments.