Relays up to 100 mA can be driven by the 555 with the recommended circuit. The circuit is from an article in the September 1992 Radio Electronics magazine.
This typical crystal oscillator configuration can generate signals up to a few tens of megahertz...
This simple servo can be built by coupling a potentiometer to a reduction box with a 3 to 6V...
This constant current source for high voltage loads was obtained from a 1967 General Electric...