This circuit was found in a Motorola documentation from 1968. The circuit makes use of FETs and bipolar of the time and can be applied to modern equivalents.
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...