Signals of up to a few tens of kilohertz can be generated by this circuit found in a European publication from the 1980s. Transistors admit equivalents and the unijunction can be 2N2646.
This circuit was found in an old American optoelectronics manual. The circuit makes use of an...
Waking up to a loud and clear sound from an audio oscillator, after up to 5 hours of sleep, or...
We found this circuit in Motorola's 1990 Linear Databook. The component used is unusual. The...