Electromagnetic Pen




This pen-like object turns into a magnet, an electromagnet. How it all works: When a DC power supply goes through a coil of magnet wire, some of the energy is stored around the coil in a field. Introducing my first instructable: Electromagnetic Pen!
(Doesn't actually write. Just looks close to a pen) You don't have to use battery holder, you can use a bench-top power supply! 

http://www.youtube.com/watch?v=AERfL4Q5JJo   < around ten second video!

Step 1:

Tools needed:

Soldering gun


Helping Hands (optional)

Wire strippers

Wire cutters

If I use some tools not listed. I will post.


Magnet wire (a lot)

Electrical tape

Steel rod (Mine is a 6 inch steel rod) Better if you use iron.

Heat shrink (just a little bit shorter than steel rod. The rod should slide through the heat shrink easily)

Small push button (momentary- Completes circuit when pressed) 

Battery holder (doesn't matter size. Just don't use a 9v or it will get too hot. Or use a desktop power supply)

Step 2: Wrapping Magnet Wire

Wrap magnet wire around a lot until you are close to the edge of steel. Make sure there is bare steel on one end. Tape with electrical wire and leave some out around 5 inches.

Step 3: Center Heat Shrink...

Center heat shrink next to the steel bar so that steel bar is barely sticking out.

Step 4: Place the Switch

Find a spot for switch. You need it to be close to your finger. You hold it like a normal pen. Make a small hole for switch wires in the heat shrink. (You don't even have to put on a switch on the pen.)

Step 5: Make a Hole for Switch Wires...

If you think it will short out, put heat shrink tubing around solder joints. Find the end with the steel that is poking out the farthest (this is the part of magnetic side on right) Solder an extra length of wire to opposite side with the bare steel side.  Make sure the wire sticks out, an inch or so, farther than steel. Do same with other wires.        (I'm trying my best to say this clearly. Sorry)

Step 6: My Switch Idea.

Not good. But it will work. If you find or know of a better spot for switch. Go ahead and place it where ever.
(You don't even have to put on a switch on the pen.)

Step 7: Almost Done!

At the end (top of pen) there should be four wires. Hopefully you took note on which is which. Hook up one wire from magnet wire to one wire from switch wire. Hook the other end of magnet wire to one terminal of your DC power source. Hook up the switch and other battery terminal together.      (You don't even have to put on a switch on the pen.)

Step 8: DC

I use a battery that is charged by a solar panel connected by a wire from battery to pen. 



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    10 Discussions


    1 year ago

    What is the use of the four wires and the batteries


    6 years ago on Step 8

    what is the intended application of this? I can imagine some uses but am more interested in applications you had in mind

    1 reply

    Reply 6 years ago on Step 8

    Hello, thanks for viewing this instructable. I made this to help get parts out of my small parts bin. It is hard to get what I want out of it so I made this to help.


    7 years ago on Introduction

    u should rename it to E.M.P eletrical magnat pen!!!!


    7 years ago on Introduction

    I'd love to see examples of general uses for this: wiping cards, hard drives, causing havoc... the usual!

    2 replies

    Reply 7 years ago on Introduction

    Well, It is not very strong but when you have bigger steel rod and more current, the stronger it will be! (Not for use to delete memory off hard drives! hehe)


    7 years ago on Introduction

    wonder if you up the gauses and perhaps make a point at one end (perhaps use a screw or nail in the end) if one could draw patterns on steel, and then get metal filings to stick.


    7 years ago on Introduction

    The next logical step is to create a functioning pen with an electromagnet concealed inside....

    I can almost smell the mayhem.

    Mark Rehorst

    7 years ago on Introduction

    I'm not so sure I get the point of making an electromagnetic pen, but I really like the white board as photo background technique! It let's you add notes and arrows, and as much text as you can fit in the photo. Brilliant! I'm going to use that technique on an 'ible one of these days.