This circuit was obtained from the March 1994 Electronics Now magazine. The circuit uses a common transistor which can be a low noise type such as the BC549.
Found in a 1980s telecommunications documentation, the circuit presented acts as a product...
This circuit was found in the Electronics Experimenter Handbook from 1991. The circuit controls a simple...
The time obtained in this circuit, from a 1978 publication, depends on R3 and C. R3 can have...