Introduction

Due to the great repercussion of an old project on the internet, I decided to develop a DIY kit of it, keeping in mind good performance, robustness, simplicity and low cost. Meet Easy-Flyback driver!

Specifications

Power supply: Generic SMPS, 24V|30A (15A is plenty for only one unit, I run 2 units);
Oscillator: 50% duty-cycle square wave generator using IC555 timer, 18 to 42kHz frequency range, tuned at 22.5kHz; 
Zero cross detector: Schmitt trigger using LM311;
Power transistor: MOSFET, IRFP260N (recommended), soft turn-on (for lower current spikes from the resonant capacitor bank) and fast turn-off (for lower switching losses);
High Voltage Transformer: CRT TV flyback transformer, JF0501-21835;
Primary coil: External, 8 turns of 0.5mm² PVC isolation wire;
Resonant capacitor: 3x 250VAC|100nF WIMA MKP10 polypropylene film capacitors in parallel for 250VAC|300nF capacitor bank;
Primary current: Up to 16ARMS, 28A peak at operation and 60A peak at oscillator’s startup every time it’s fired (this bug has been solved in the second version “Easy-Flyback II”);
Primary peak voltage: Up to 180V under operation and 240V at the oscillator’s start-up (avalanche in action);
Output: Arcs can jump across 100mm+ air gap, the recommend distance between the electrodes is no more than 50mm to avoid damage in the transformers insulation.  The power levels can easily be greater than 250W per unit.

Schematic

Drivers

Power Supply

Flyback Transformers

The Whole Setup