This highly sensitive light sensor was found in a 1970 General Electric documentation. The circuit can use the 2N2646 for the UJT and the phototransistor can be of any type.
We found this circuit in an article in Electronics Now magazine from November 1997. The circuit uses...
This circuit provides just over ½ W to a small speaker. We found this configuration in an old...
In the figure we have a typical relaxation oscillator with a SIDAC as well as waveforms and...