Computer Tricks and Secrets

Short answer: a touchscreen stylus works by conducting the tiny electrical charge from your hand to the screen, so you can build a simple one at home from a cotton bud, aluminium foil and an empty pen in about five minutes. It is a fun trick, though for real drawing or note-taking a cheap proper stylus is far better. Here is how to make one and how it actually works. Why a homemade stylus works at all Phone and tablet screens are "capacitive", they detect the small electrical charge your body carries, not pressure. That is why a gloved finger or a plain plastic pen does not register. To fake a finger, a DIY stylus needs two things: a soft conductive tip that touches the screen, and a conductive path from that tip to your hand. Method 1: the cotton bud stylus (5 minutes) Take an empty ballpoint pen (remove the ink tube) or any hollow tube. Push a cotton bud into the tip so the cotton pokes out slightly. Wrap aluminium foil around the pen body and up over part of the...

Short answer: a buzzer turns an electrical signal into sound. The two common types are piezoelectric (a crystal that vibrates when voltage is applied) and electromagnetic (a coil and magnet that move a diaphragm). You can build a simple buzzer circuit with a battery, a switch and a buzzer in minutes. Here is how it works and how to make one, a great beginner electronics project. What a buzzer actually does A buzzer is an audio signalling device: it converts electrical energy into a beep, click or ring. You hear them in doorbells, alarms, microwaves and toys, whenever a device needs to make a simple sound to get your attention. The two main types Type How it works Piezoelectric Voltage flexes a piezo crystal, which vibrates and makes sound Electromagnetic Current through a coil moves a magnetic diaphragm to make sound Piezo buzzers are small, cheap and common in electronics; electromagnetic ones can be louder. Active vs passive buzzers (important for building) Acti...