Found in documentation from the 1980s, this circuit can have several adaptations to use modern transistors and LEDs instead of the lamp. The power supply voltage can also be changed.
This precision circuit was found in ancient American documentation. The most critical component is the...
Using an LDR, this Philips circuit directly activates a relay when light strikes the sensor. The...
This circuit can be used to obtain control signals from an infrared emitting source. The circuit is...