As with everyone else I too have built many of these circuits and found a few little tricks that keep them working.
One of the more critical things you are overlooking is that an ignition coil driver circuit is intended to drive an ignition coil with a fixed distance spark gap on the end of the secondary as in a spark plug.
Also consider that the circuit has one end of the secondary tied to the + side of the system and not the negative side so making your ground return to the positive side instead of the negative side prevents the HV discharge from having to find a way through circuit when the switching device is open.
Lastly a few .01 to .1 uf capacitors across the power leads of your regulator inputs and outputs plus the 555 itself will bring down any additional odd spikes and circuit noise to levels that they may find far more survivable.
On my circuits I never ran regulators but simply ran my power input to the 555 through a 10 or so ohm resistor in series with a diode followed by a few capacitors ranging from .01 to 100 or so uf.
One of the more critical things you are overlooking is that an ignition coil driver circuit is intended to drive an ignition coil with a fixed distance spark gap on the end of the secondary as in a spark plug.
Also consider that the circuit has one end of the secondary tied to the + side of the system and not the negative side so making your ground return to the positive side instead of the negative side prevents the HV discharge from having to find a way through circuit when the switching device is open.
Lastly a few .01 to .1 uf capacitors across the power leads of your regulator inputs and outputs plus the 555 itself will bring down any additional odd spikes and circuit noise to levels that they may find far more survivable.
On my circuits I never ran regulators but simply ran my power input to the 555 through a 10 or so ohm resistor in series with a diode followed by a few capacitors ranging from .01 to 100 or so uf.
