Using a PI Zero to control a tesla coil and play MIDI files

The project is to make an expandable system for making a tesla coil using a core of a Raspberry Pi (PiZero) and a PIC18F14K50 as a controller

The goals are to

1. Control a Tesla coil from I2C (Done)
2. Control a Tesal coil from a Raspberry PI (Done)
3. Develop a background program to control the Tesla coil from a number of sources. (Done)
4. Play MIDI from a file in the Raspberry PI (Done)
5. Play MIDI from an external Keyboard (Done)
6. Impliment Over current detection. (Sort of Done)

Here it is so far.

Mains power full bridge rectified and smoothed with a 900uF cap

Fed into a full bridge of 4 x G4PF50WD driven by a 4 way GDT . Phase information from the coil is picked up from a current transformer 100:1

Raspberry Pi Zero connected to a PIC uP board that does the accurate timing via I2c. Currently the I2C needs a level converter from 3.3 to 5V

The PI Zero communicates with the laptop via RS232 over a 1Mbd fibre link.

Laptop USB serial fibre interface. uses an Aduino Uno to give USB to serial and to drive the fibre link.

Re built/tidied up topload. Needed re-tune, now much longer sparks for lower voltage/on times. Need to get to running from direct mains so I can lose the variac. Oh I had to test with a tune, of course.

Traces from various parts of the circuit. Blue – on time. Light blue – Primary Current. Yellow / Purple – Ariel

I got the PCBs from OSH park and I realised that they send 3 of everything, as I had some spare components. I built another driver and change the software a little to split the midi to two I2C Ports.

The PI Twin was born (or TauTesla coils )

As Osh park send three boards, So I built another set of boards and tweaked the software to run two midi channels to two tesla coils.

First day out,Nottingham Gaussfest

Ran all day at the Notts Gaussfest with no issues,(and no heat sinks on the IGBT’s 🙁

A top view of a PiZero Double Controller – 1 Pi Zero 2 Midi channes, 2 drivers, 2 bridges

Nottingham Gaussfest 2016 – Airwolf!

Power limited, no heatsinks 🙁

A Safe(r) enclosure

As I had a run of demos lined up I decided that the case should be a little safer. Running with a single sheet of acrylic with all of the live PCBs was not ideal.

The case is made from an recycled sign, its made from 6mm acrylic and has a removable lid (now with cooling fans) Much safer now.  🙂

connected to Two Tesla coils

Derby Geakeasy 2016

Power limited due to safety…

Cambridge Teslathon 2016 – Mary Poppins

Plenty of power running very well.

Block Diagram

Construction

Rs232 fibre to RPI/Pi Zero terminal

Solid State Tesla Coil Bridge

Winding Gate drive and Phase Transformers

Pi Zero Topload construction

Pi Zero Secondary Construction

Pi Software setup.

I2C Driver Board

Construction and documentation still in progress, more to come:-

Primary Capacitor / Tuning – Coming Soon
PIC uP setup / Software – Coming Soon

If you are interested, If I get enough requests, I will consider making a kit email me [email protected] 

The kit will be for experianced builders only due to SMT componants and the risk of electric shock.

RPI Twin Tesla coils on the RI Christmas Lectures 

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