Code practice oscillator

Project 1 - A CW Practice oscillator.


This circuit uses junk box components and stripboard assembly to build an "astable multivibrator" oscillator.

Two NPN transistors provide the switching in association with 2 timing capacitors and 4 resistors.

The internal working bit  from an old dynamic microphone is used as the sounder. These typically have an impedance of 500 ohms. In this circuit it gives acceptable sound output when connected in series with one of the 2K collector load resistors.  The board layout suits NPN transistors found  in thejunk box. No tracks require cutting as every node of the circuit has a different track allocated to it.





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