Based on the 4017 integrated circuit, this circuit of a European 303 Circuits from the 90s, generates a pulse train in a relay that mimics the dialing of a telephone.
Found in a European magazine from the 1980s, this circuit can amplify signals from 10 kHz up to...
The circuit in the figure uses the four current amplifiers of the LM3900 to generate a sawtooth signal...
This circuit is from a Radio Electronics magazine from August 1960. It is a commercial circuit for marine...