This circuit was found in the May 1984 issue of Radio Electronics magazine. It analyzes the exhaust gases emitted by a car. The circuit uses a special gas sensor from that time.
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...