This circuit was found in the May 1982 issue of Radio Electronics magazine. The circuit inverts the polarity of a power supply to obtain a voltage of -5 V.
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...