Morse Code Self-Tutor

Morse Code Self-Tutor

Morse Code Generator Circuit. Basically, it is an Astable Multivibrator using Timer IC555. You can use any of these timer IC's: NE555/LM555/NE556/ LM556,etc. 

This is only a normal circuit for practicing the Morse Code. I advise to have a Morse Encoder if you are learning the code so that with every new word you may tally your circuit response.

Working:

The 555 used works as a Square Wave Oscillator / Square Wave Generator. To achieve this we need to calibrate the On time and OFF time of the pulses.

The time can be calculated by this formula:

T-ON= 0.693 x (R3 + R1) x C4=     sec
T-total= R1 + (2 x R3 )=    sec

Whenever the switch is pressed , the Loudspeaker activates and we hear the bit.
An altenative to the Loudspeaker , you can also use a Continuous Piezo buzzer but make sure to keep the frequency as high as possible.But make sure to eliminate the pot when using the Buzzer.

Frequency= Inverse of Total Time=    Hz( in Hz if time in sec)

Switch / Key / Paddle :

Instead of using this kind of paddle , I made a rather easy switch with a few stationary items.

All you need is some strong glue, Two erasers, one tensile small spring (Strong enough), one small block , two small metal ruler/scales and few strong Rubber Bands.

Use FLEXIBLE METAL SCALES ONLY ; NO PLASTIC SCALES TO BE USED

First assemble these items on  desk. Then, grab the scales and choose the common side wherein you will sandwich the block at one end. Take the small spring and glue it very very strongly on the other side of the ruler but NOT on the edge.Leave some space for the erasers. After having attached the string and the metal block , start to glue the erasers on both these scales.[Refer the above diagram, Replace the knob by the erasers BUT stick them on the lower side]. Then take two thin Metal Sheets about the size of the plane of the eraser.Now , stick them on the erasers and solder the planes with some wire to the circuit for providing some flexibility for the switch. And YES!! Your switch is ready .

 I couldnt upload mine due to some camera format problem.So , I 'm very sorry for you will have to visualize the switch by yourself.

Conclusion:
Make sure you determine the frequency very accurately with that of the components.The capacitor connected to Pin5 is responsible for changing the pulse period.So , choose the value of capacitance wisely.Moreover , I suggest rather than changing the capacitor for desired frequency, one should change the Resistance values as they are more flexible.

My suggestion is that try this circuit on a breadboard rather than using laminates as you can use 555 to make wonders happen and 555 happens to be  a very useful IC for hobbyists as well as in the Industry.