Found in documentation from the 1980s, this circuit uses an operational amplifier from that time. Transistors are also from the era, and general-purpose equivalents can now be used.
A first circuit that uses a phototransistor as a detector and is suitable for covering short...
We found this circuit in recent English documentation. The circuit uses CMOS technology and can be...
We found this circuit in an old Mullard (Philips) documentation on the 555 and 556 integrated circuit...