- The One, Only & Official - * HOME PAGE * ABOUT ME * DISCLAIMER * CONTACT
-------------------------------------------------
Top of Form
Bottom of Form
Flyback driver #2: NE555 quasi-resonant
16. March 2012
This single transistor flyback driver topology was created in response to achieve higher efficiency and higher output voltages from ordinary CRT television flybacks (diode split flybacks), for experiments such as x-rays or ionic lifters, without having to make any external HV multipliers. Since these flybacks are normally sealed in epoxy and can withstand an output voltage of 50 to 75 kilovolts, why not use them in drivers such as this one… Moreover, the simplicity of this circuit also adds a possibility of some simple audio modulation of the arc. So, let’s begin!
The quasi-resonant topology
But to say the least, the first driver I have built with this topology had an AC flyback and an input power supply rated just 60 watts. The result was a compact, short-circuit proof, high voltage “lab” supply with frequency control, some active cooling, audio modulation (singing arc, or a plasma speaker), two 5-15 kV high voltage outputs (AC and DC) to play with things such as plasma globes, small Jacob ladders, multipliers, and so on. The machine, due to its intended purpose, did not provide big fat arcs – however I think it’s still impressive and worth mentioning. Behold!
High voltage enthusiasts, who are familiar with the classic NE555 flyback driver, will notice the foil capacitor across the primary winding, which really makes wonders. (More on this here.) The output voltage depends on the oscillator frequency (set it to variable 15-30kHz for output voltage fine-tuning), number of primary turns and on the resonant capacity. Fewer turns, lower frequency and lower cap values such as 100-330 nF are going to produce over 60 kV out of a DST flyback with ease; more turns, higher frequency and higher capacity (up to 1 uF) will
Links: * My YouTube channel * eBay items on sale * ------------------------------------------------- Newest additions * TESLA ARF 300 headphones * EDOS high-range dosimeter * Triple333 (333-333-333) * MEOPTA 87328 16mm projector supply * 3D X-ray setup Copyright © 2012 Jozef Bogin. All Rights Reserved