This circuit contains only capacitors, resistors, NPN transistors, diodes, and a single 9V power source. The capacitor at ground is simply to help with startup. It is not needed in real life. The AC source that is not connected to anything is just to improve simulation quality and is also not needed in real life. This circuit provides about 60V, and that can be made higher by extending the capacitor-diode chain on the top.
