This circuit reminds the driver when he removes the keys from the ignition, leaving the lights on. The circuit is from an August 1974 Radio Electronics magazine.
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...