Simple LED Circuit

Comments

• bill190 Posts: 769

  2010-10-17 00:18 edited 2010-10-17 00:18

  Perhaps a Capacitive Sensor would work? Here is info on that...
  http://en.wikipedia.org/wiki/Capacitive_sensing
  
  Also there are pressure sensors sold at the Parallax store. And a reed switch which activates when a magnet is nearby. See the sensors area here...
  http://www.parallax.com/Store/tabid/60/Default.aspx
• Leon Posts: 7,620

  2010-10-17 02:44 edited 2010-10-17 02:44

  If the magnet makes contact, it could simply complete a circuit. No additional components required!
• Ragtop Posts: 406

  2010-10-17 06:50 edited 2010-10-17 06:50

  I think they want the light on when attached to any metal object and off when unattached with the battery attached to led/magnet.
  
  Maybe if the led/magnet consisted of two magnets insulated from each other. Ground wire from battery to one and led ground wire to the other. The metal object might complete the circuit.
• Phil Pilgrim (PhiPi) Posts: 23,514

  2010-10-17 11:02 edited 2010-10-17 11:02

  The metal object might be painted, though. Anyway NWCCTV needs to clarify where the magnet and piece of metal are relative to the circuit containing the light.
  
  -Phil
• NWCCTV Posts: 3,629

  2010-10-17 11:55 edited 2010-10-17 11:55

  The magnet would be on a flat surface. A ball will contain the LED and when the ball contacts the magnetic surface the LED will light. Thanks for the posts. I think I have a starting point now. Oh, and Ragtops theory is correct.
• erco Posts: 20,261

  2010-10-17 14:06 edited 2010-10-17 14:06

  So no HiFi, WiFi, 4G, Hotspot, iPhone, Bluetooth, Quadcore, Propeller, Blackfin, AVR, PIC, Arduino, dongle, or GPS cross-referenced to a database of every metal object known to man?
  
  
  Not even a Stamp, USB adapter, solar cell, shift register, or relay?
  
  
  You mean like a magnet and a switch???
  
  
  
  
  
  Sheesh. That's hardcore.
• NWCCTV Posts: 3,629

  2010-10-17 19:51 edited 2010-10-17 19:51

  Yep, Like a magnet and a switch. Small, cheap and simple!!!!!
• Franklin Posts: 4,747

  2010-10-17 20:13 edited 2010-10-17 20:13

  Sounds like a reed switch is what you are looking for.
• Phil Pilgrim (PhiPi) Posts: 23,514

  2010-10-17 20:38 edited 2010-10-17 20:38

  I'm still confused about where the magnet is. So let me see if I understand: you have a ball (steel?) with a battery, an LED, and some sort of switching device. This gets stuck on a magnetic surface. Or is the magnet in the ball, and the ball sticks to any steel or iron surface, e.g. refrigerator door? A drawing would certainly help.
  
  -Phil