This circuit was obtained in an Electronic Design from the 80's. It has the adjustment of the gain through a simple potentiometer. The power supply must be symmetrical.
With the configuration shown in the figure, a common 12 V lamp lights up when light no longer...
This circuit was obtained in documentation on medical applications from 1966. The circuit is used in...
We found this circuit in an Australian publication from 1991. The circuit has good sensitivity, presenting...