This old automotive circuit was found in an August 1971 Radio Electronics magazine article. The transistor is a Darlington transistor rated for the wattage of the bulb.
This 5.1 MHz oscillator was found in a 1980s American documentation. The used operational...
A NOR gate can be improvised using one NAND gate of a 4011 as shown here. The diodes are...
Found in the September 1982 issue of Radio Electronics magazine, this circuit triggers a relay...