My third biggest fear in life is having my laptop play a loud startup sound in a quiet library or crowded lecture hall. It comes right behind my fear of moray eels and small pebbles.
To address this serious problem, I made a small hardware mute button for my keychain.
The construction is rather straightforward. You will need a 3.5mm stereo jack, about 10cm of insulated wire and optionally a resistor in the range of 2.2k – 10M. The wire shouldn’t be too thick, anything bigger than about 0.5mm diameter will be hard to fit through the solder connectors.
The basic ingredients, resistor optional
After stripping the last cm of the wire on both ends, twist the end of the wire together and thread the result through the sleeve connector of the jack. The sleeve is usually the the longest and widest connector.
If you are quick with the soldering, you can already secure the wire with the metal flaps.
You can now optionally add a resistor from the jack to the tip. However this is only really useful, if you want to build something like an intelligent key hanger (see below).
With added resistor (optional)
Solder all connections and clip any protruding pieces of wire. Add the audio jacks cap and you are done.
Congratulations on your very own hardware mute button!
Some more fun things to do:
- Use different colors of cable, to identfy different keys
- Make a key holder out of female audio jacks
- Use different valued resistors to automatically identify which keys are currently plugged into your key holder