This is one of many possible touch switch configurations using CMOS integrated circuits. The circuit is from a 1980s American documentation. The power source must be isolated.
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...