Control Led Using Magnet and Reed Switch : 4 Steps

IN THIS PROJECT I'M USING MAGNETIC STICK TO CONTROL LEDS OF DIFFERENT COLORS BY USING REED SWITCH.

Step 1: SCHEMATICS

Step 2:

How does a reed switch work?

Reed switches come in two main varieties called normally open (normally switched off) and normally closed (normally switched on). The key to understanding how they work is to realize that they don't just work as an electrical bridge but as a magnetic one as well: magnetism flows through them as well as electricity.

Normally open

As you bring a magnet up to the reed switch, the entire switch effectively becomes a part of a "magnetic circuit" that includes the magnet (the dotted line in the artwork shows part of the magnetic field). The two contacts of the reed switch become opposite magnetic poles, which is why they attract and snap together. It doesn't matter which end of the magnet approaches first: the contacts still polarize in opposite ways and attract one another. A reed switch like this is normally open (NO) (normally off), unless a magnet is positioned right next to it, when it switches on, allowing a current to flow through it.

Take the magnet away and the contacts—made from fairly stiff and springy metal—push apart again and return back to their original positions.