This is an efficient flyback driver for modern cylindrical rectified television flybacks. Frequency range can be increased using multiposition switch for other values of C3 capacitor, for example 2 nF for 80KHz-200000KHz, but didn't found flybacks with so high resonant frequencies, in addition with higher values of c3 , eg 200nF, 2uF the frequency will drop making possible the use of ignition coils, and rectified power transformers @50Hz to charge high voltage electrolitic caps at 300-400V).
The flyback driven in this way can supply a significant current, aldough the heart fibrillation starts at 30mA I recommend caution to avoid painful arc-burns. The arc is a hot plasma, never operate the circuit in presence of flammable substances. Charging high voltage capacitors is a serious life threat, so if you arent unexperienced just draw arcs and no more This device when rectified generates static voltage that can be a little annoying