How to make a prank musical caps-lock keyboard

Step 7 How does it work ?

Ah, but how does it work?

Here's the schematics.

I've highlighted the new connections and transistor in red.

The transistor replaces the switch on the musical module. A transistor is essentially an on/off switch that turns on when it receives current on the B pin. When you press the caps-lock key, the keyboard tries to light up the LED, which sends a current to the transistor and triggers it like a switch and turns on the music! When caps-lock is pressed again, the keyboard turns off the LED, which stops the current to the transistor, which opens the circuit again and stops the music.

Simple!

Thanks Kipkay for the original idea.
Check out my blog for my other projects.

Thanks for reading!
Lionel.