Doorbells Work
Doorbells are one of those everyday devices we take for granted. On the surface, they couldn't be simpler: You press a button, which completes a circuit, which turns on some sort of noisemaker. In a world full of , and , that doesn't seem so impressive.

But when you take off the cover and see what's going on, conventional doorbells are one of the coolest machines around, precisely because of their simplicity. Doorbells put the basic principle of electromagnetism to work in remarkable, innovative ways. In this edition of , we'll look inside some standard doorbells to see how these devices translate electric current into buzzes, rings and chimes.

  • USB Ports Work
  • Teddy Bear Camera under $200.00
  • Hidden Camera Video Recorder w/700ft. 2.4GHz Transmitter & Receiver
  • The Evidence Is In
  • College laboratory security lacking, investigators say
  • New Camera Uses Wi-Fi To Stream Video
  • Home Dry Cleaning Works
  • Investing In the Futures of Security
  • Securing a Historical Treasure
  • C
  • NetStream DigiLinX IP-Based Multi-Room Audio
  • Security Camera News