This circuit that imitates the sound of the cowboys' calls with their “louder” was found in a Hands On Electronics from the 80's. The integrated circuits used are from that time.
This circuit was obtained from an English circuit manual. Components are common and LEDs can be 3...
Found in a 90's EDN, this circuit generates signals in the frequency range given by the graph. The...
This circuit can generate signals from 100 kHz to 1 MHz depending on the L1 coil. For the medium...