This circuit was found in a 1989 publication. The operational amplifier supports equivalents. The LED range can be expanded.
Found in the 1976 Siemens transistors manual, this circuit works with AM or FM IF signals. In the...
Three 4011 NAND gates and two more components - a resistor and a capacitor make this oscillator very...
This photoelectric circuit was found in a 70’s Ferranti's documentation. The circuit uses an...