This circuit was found in documentation from the 1980s. Transistors are general-purpose types like the BC548 for NPN and the BC558 for PNP.
What we have is a powerful flasher that can be powered by voltages of 12 V like the one obtained from...
A 0 V signal initiates sampling on this circuit suggested by documentation from the 1970s. The...
This circuit is used with low impedance microphones, such as small speakers, magnetic capsules of...