WeiMeet Reed Switch 2 x 14mm Normally Open N/O Magnetic Induction Switch Electromagnetic for Arduino (12 Pack)

for this tutorial we need read switch a 220 ohm and 100 ohm resister LED multimeter battery breadboard arduino nano magnet and few connecting cables read switch was invented in 1936 by Walter B Elwood in the Bell Telephone labs reads which consists of a pair of ferromagnetic flexible metal contacts typically nickel are an alloy as they are easy to magnetize and doesn't stay magnetized for long separated by only few microns coated with hard wearing metals such as rhodium ruthenium to give them a long life as they switch on and off in an airtight glass envelope the glass tube consists of an inert gas typically nitrogen or in the case of high voltage it's just a simple vacuum since the contact of reeds which are sealed away from the atmosphere they are protected against atmospheric corrosion the hermetic sealing of the reed switch makes them suitable for use in explosive atmospheres where