The tone generated by this bell changes when we press and release the switch. The circuit is from a 1985 Radio Electronics. Some changes can be made to improve its performance.
This useful power supply was found in an 1985 Italian publication, but can still be assembled...
This dimmer for 12 V incandescent lamps was found in a 1966 General Electric documentation. The circuit has...
With this circuit any number of 4017 integrated circuits can be connected in series. The circuit is...