This circuit was found in the April 1984 issue of Radio Electronics magazine. The integrated circuit used is a type of time that already includes the power supply.
Using a 4046 PLL this circuit recognizes a 1.6 to 1.8 kHz tone by driving an output LED. The...
This battery charger circuit was found in ancient American documentation. The components are...
This circuit is of great use today, when solar energy is becoming increasingly important. The...