This circuit was found in an American documentation from the 1980s. The sensitivity ranges from 100 mV to 1 V. The supply must be done with an excellent filtering source.
Settings like this can be found in this section and on this website, but from different sources of...
This circuit with TTL output was found in a 1968 EEE. The transistor can be of general use. The...
Found in a 1980s manufacturer documentation, this circuit can be used as an optical shield. The...