This gas sensor circuit was found in July 1976 Radio Electronics magazine. The TGS sensor was a common type at the time. Note the power supply to the circuit.
This circuit was obtained in a documentation of the 80s, using operational of the time. The...
In the figure we have a third fast adder that we found in an 80's Electronic Engineering. The circuit can...
We found this simple music box circuit that can also be used in a musical bell in a 1991...