Dollar Store Door Alarm — Pulse Motor

This shows a ‘Dollar Store” door alarm that I converted to a pulse motor drive unit. The door/window alarm is an electronic oscillator that is turned on and off by a magnet triggered reed switch. I reconfigured the device to pulse and make a four N facing magnet rotor turn. Several methods were tried unsuccessfully. What finally worked was to remove the existing reed switch completely and add a another better one at the bifilar coil primary winding. The coil secondary winding was removed from the speaker and attached to an LED. This video was shot with an old iPhone 4s.

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