In the previous episode of Hacked! I showed you how I modified a CCFL inverter in order to create an electric arc that can ignite fireworks. But even after I optimize the circuits by adding a 220 nano farad capacitor in parallel to the original one, in order to lower the frequency of the sine wave from 320 Kilohertz to 76 Kilohertz, there still were some problems. For one, the circuit is not portable because of its bulkiness, and most importantly its power requirements of up to 12 volts and 3 amps cannot be fulfilled by a Li-Po battery with a voltage range of 4.2 volts to 3 volts and a current capability of 2.8 Amps. So in this video, I will show you how to create a similar circuits that can fix those problems and ultimately complete the DIY portable Arc Lighter project. Let’s get started! The housing I got for my DIY arc lighter is a bit bigger than a commercial one, But still fits comfortably in the pocket. The transformer from the CCFL inverter, which is mandatory for such a circuit, did barely fit inside this case, but I wanted to go smaller. Thankfully I had another CCFL inverter from an old monitor laying around that contained a smaller transformer So I desoldered it from the circuit, removed its protective tape, and started unwinding it’s center-tap primary coil. It was rather interesting to find out that each coil also consisted of 14 turns, Just like the bigger CCFL transformer, but strangely enough, there was no feedback coil to be found. Nevertheless, I then created a new primary coil consisting of three turns, soldered two wires to the secondary coil, hooked the primary up to a square wave inverter, and started increasing the voltage. But sadly, the secondary coil was not well enough isolated, And thus could not create electrical arcs, but definitely plenty of heat So I had to abandon the idea of using the smaller transformer and focused on the old one. To form a resonant circuit, I firstly soldered 2 220 Nano Farad capacitors in parallel to the primary coil which will later create a sine wave with a frequency of 75 Kilohertz. The center of the primary coil gets connected to a 0.1 Milli Henry inductor Which I salvaged from the previously Hacked CCFL circuits to act as a constant current source when connected to the supply voltage The oscillator circuit itself consists of two IRLU3110 set Mosfets, two 220 or gate resistors, and 2 UF4007 diodes in this arrangement. Since the required components are just a few, I simply used a bit of silver copper wire to connect them to one another in Midair according to the schematic. After adding output wires to the transformer and applying a voltage of 2.6 volts to the circuit, this sine wave was established on the inputs but it still required a voltage of 4 volts to create the electrical arc. So I had no choice, but to desolder the circuit from the transformer, remove the primary coil and create a new one, but with one less turn. So 2 turns for each half and thus 4 in total. Then I reattached the circuit and tested it once again. This time the arc was established at a voltage of 3.3 volts, perfect for the LiPo battery. Well at least if the input current wouldn’t be 3 amps. To fix that, I added 4 31 pico Farad 6Kb capacitors in series to the secondary coil to limit the output current, which clearly lowered the input current but also made the electric arc a lot weaker and pretty much unusable. So we have to stick to the high current draw which my original planned LiPo battery cannot provide. thankfully though, I had a fitting replacement battery year that could supply such currents. And after adding a push button and a tPU 4056 charging and protection board to the circuit, It was supposed to work fine, But it didn’t. The problem was the overcurrent protection of the board, which interrupts the current flow after a couple of milliseconds. The solution was to bypass the protection features, which is not that recommended, but since the electric arc is only established with a voltage higher than 3.3 volts, We at least know when to charge the battery. And now that we finally have a decently working prototype, how does the oscillator circuit actually work well first off the resistors charge up the gate of the Mosfets. Since no two mosfets are completely the same, One of them will turn on first and connect one half of the primary to ground, and thus a rising current will flow. While that is happening, the gate of the other mosfet is connected to ground through the first mosfet, and thus cannot turn on. Once the oscillation of the resonant circuit reaches a point where the lower half has a ground potential, The gate of the first Mosfet can discharge, which thus turns it off, and the second mosfet can finally turn on and repeat the same cycle just in reverse. And just like, that both mosfets turn on and off one after the other, and thus in combination with the resonant circuit, create a sinusoidal voltage and current. Now all that was left to do was to salvage the parts from the prototype ,and Prepare the housing of the arc lighter. For that I drill 2 1.5 millimeter holds for 2 1.5 square millimeter wires as the electrodes in the top section, and another 3.5 millimeter hole in the front for the push button. Then I used a file to create a rectangle cutouts on the bottom for the Micro-USB charging port. Afterwards I secured most of the parts inside the case with hot glue, soldered the oscillator components onto a small piece of perf board, and used 0.75 square millimeter wire to connect all the components to one another according to the completed schematic. After our last test I closed the case and the project was complete! And it was time to play around with the electric Arc. But as always, when it comes to high voltage, be very careful, since it has the potential to be Lethal. Anyway, I hope you liked this project. If so, don’t forget to like, share, and subscribe. Stay creative, and I will see you next time!