This symmetric 30 mA x 15 V power supply was found in the Ferranti transistor manual from 1974. Transistors are common types at the time.
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...