This 1988 circuit makes a back-and-forth of LEDs whose speed is controlled by P1. All components used are common and the circuit can be powered by voltages from 6 to 9 V.
Found in a 1967 American electronics magazine, this circuit has an input impedance of 2000 ohms....
This circuit makes use of components from the time it was published. The TCA151 is not a common...
This ultrasonic insect repellent was found in American documentation from the 1980s. The...