How do I connect a 6V battery to an electromagnet with a reed switch?

Question

This is a science project that I am working on and I'm trying to find a compatible reed switch with very limited electrical knowledge.

Answer 1

Reed switch can be purchased from any shop that sell electronic parts.

It is not expensive,sometime a pack of ten sell for $2.

Get the bigger one,like 1 inch long. Buy a 6 volts light bulb about 300 to 600 ma. Now connect them as following:

6v battery + to one side of reed switch......other side of reed switch connects to one side of light bulb.......other side of light bulb connects to the - of battery. At this time,light bulb shall not light up. Now placing a strong enough magnet (or electromagnet as you wish but make sure it is energized) nears the reed switch. Light shall come on.

Move away the magnet,light shall come off.

Answer 2

First thing, a reed switch is a magnetically operated switch. The actual switch consists of a glass tube which has at least two contacts inside usually in vacuum. Because they are usually made for maximum sensitivity, they have low mass reeds in them and very small contacts. That means the can not be used with capacitive or inductive loads because of high transitory currents and voltages. You can get mercury wetted contacts but these have there own problems and I wouldn't recommend them.

Rather, I suggest you make a buffer amplifier to allow you to interface with the load. It would consist of a transistor and a couple of resistors. The reed switch would switch the base current switching the transistor on and off and isolating the magnetic circuit.