This small phonographic amplifier was found in a 1967 General Electric documentation. The integrated circuit is from that time, providing 1.5 W of output power.
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...