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 is from Mallory 1968 documentation. The circuit makes use of period components and...
This circuit can be applied to several logics. The circuit is from an Electronics Now from the...
In figures 1 and 2 we have two current drains that can be made with operational amplifiers and...