HELP! Magnet activated circuit

Discussion in 'The Projects Forum' started by Tanno_uk, Jun 6, 2011.

  1. Tanno_uk

    Thread Starter New Member

    Jun 6, 2011
    Hi all!

    I am completely new to electronics but very keen to learn. I want to make a circuit which activates an alarm or light when a magnet passes through it. It is for a device I would like to make

    Would this be complicated?

    Any advice would be greatly appreciated

    Thanks all!

  2. Wendy


    Mar 24, 2008
    Depends. Know what a reed switch is? It is used for alarms on houses a lot. If there is a magnet close it is closed, if not it is open.

    There are fancier, more sensitive setups out there, but this is a start.
  3. Tanno_uk

    Thread Starter New Member

    Jun 6, 2011
    And by closed does that mean the alarm/light would come on?

    What other components would be needed?

    Sorry about my lack of even basic knowledge but I really am just starting now?

    Also, where is best to buy these components from? Can you recomend an online source?
  4. Bernard

    AAC Fanatic!

    Aug 7, 2008
    " The Electronic Goldmine " has Reed switches, # G1347, G16648, Burgler Alarm Kit # C6280; also Hall Effect SW #G1994. For a door alarm,normally open reed SW is attached to frame & magnet to door, so that wheen door is closed the SW is closed, alarm sounds when door & SW open. The Hall SW acts like a transistor which is activated by magnetic field instead of base current.