This circuit appears in several versions in publications of the time and can be modified by changing the capacitors. This one is from Radio Electonics magazine from October 1992.
This circuit activates a machine to dry hands (fan and heater) when the sensor detects the...
The operational used is like the 741. The circuit is from the datasheet and the formula that...
The second order filter shown in the figure is suggested by Texas Instruments, based on the TL081...