Hi Amigo,

Yes, when in self oscillation, the off on is so fast that the potential is compressed in time so you can get some very high voltage spikes.

You may find the wheel gets faster with a plastic bar instead of aluminum. As the magnets pass the aluminum bar, they induce counter currents in the aluminum that repel and probably slow the rotor slightly. It is ok if the magnets are embedded in an aluminum rotor turning with the magnets but very different from a part of the frame that is aluminum.

If the neon doesn't light that is ok, if it does light that is ok too. Think of the neon as an overshoot gap where if the voltage is too high and could fry the transistor, it will just be partly consumed and diverted by the neon. Like Kevin said, has fried some transistors without. He was using some more heavy duty multi coil setups compared to these smaller versions so becomes more necessary but good to get a feel for what they do.

Feel free to start a new thread on the project you want to apply radiant energy to.