the ones i made were 90 and 180v but the more
hv turns you do the higher the voltage(about 1v per turn)
this circuit runs best @2.4v-3v
Step 1: Materials.
2n3904(sometimes others work too)
winding wire(0.15mm approx)
0.2-4mm as well!
neon glow lamp (i used maplin rx70)
Step 2: Wind the hv windings.
through the middle of your toroid like the pic.
Step 3: Wind the low voltage windings.
using your 0.2mm wire wind 5 turns and make a center tap
and then wind another 5 the center tap is the positive 2.4v.
Step 4: Put together all the parts.
and test it!