This circuit digitally counts input pulses. The circuit from a November 1970 Radio Electronics uses unijunction programmable transistors. Note the counted pulse duration.
This circuit is from old European documentation. R1 depends on the output voltage of the...
This circuit can be used in an experimental link for educational purposes. based on an integrated 4093....
This circuit provides just over ½ W to a small speaker. We found this configuration in an old...