Small Morse Practice Oscillator

It is a very simple Morse code practice device, made using a NE555 timer IC and few discrete components, easy to build and fits into your pocket. You can power it with a 9V battery and practice Morse Code while walking.

 

 

SchematicWorking:

      It is a simple astable multivibrator, which generates an audio frequency determined by R3, R4, The variable Resistor and Capacitor C3.

     The frequency of oscillation is determined by

       f=1.44/((R3+(R4+RES-VAR)*2)*C3)

    If you use the variable resistor of 100K, then we can have output of 474Hz-1.38KHz which is perfect for Morse Code practice.

Construction:

  The PCB is designed  in  PROTEUS VSM which is a very good Simulation and PCB prototyping tool. I've exported the actual size design in PDF. You can download it from here and print in A4 sheet. There are various toner Transfer techniques, choose one of them and start building.

  No power switch is present, as the key powers the oscillator when closed and consumes no power otherwise. Use a straight Key and power it up with a 9V Button Cell.

73s