Light/Sound Code Practice
Morse code is also used for communicating with a flashing light. This circuit will let you practice Morse code using both sound and light.
It's also great if the sound of the oscillator bothers others in your family.
Set the Select Switch to A and push the Key, You'll hear a sound from the Speaker.
Now set the Select Switch to B and press the Key again. This time the Lamp lights up. If you examine the schematic for this Project carefully, you'll notice that it seems like the circuits for Projects Code Practice Oscillator with Tone Control in Communication systems section and Telegraph in Electric power section joined together.
Like we've told you all along, complex electronic devices are just simple circuits connected to each other.