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 circuit was found in a 1999 publication. Its purpose is to flash two LEDs according to the...
This two-transistor emitter-coupled oscillator circuit with capacitive feedback was found in the...
This circuit is from an old operational amplifiers manual. However, the setting applies to modern...