Experiments with electromagnets

Cool electromagnetic toys you can buy expt.gif (888 bytes)

Please note:  the information at the end of each article refers to the part number of that item at the source indicated.  Arbor is Arbor Scientific, ScientificsOnline is ScientificsOnline, AS&S is American Science and Surplus, EdIn is Educational Innovations.  Today, some of these items are no longer being made and are not available.

Since every one of these items use electromagnets each one needs a source of electricity such as a battery or a wall outlet.

Top Secret


This is a clever toy which shows a top spinning on a plastic base.  Even after several days, it will keep on spinning.  See Patent #3783550.  From Andrews Manufacturing.  Cost is about $11.
Arbor , ScientificsOnline , AS&S , EdIn

Space Wheel


This is similar to the above toy in that spinner or wheel will continue to roll back a forth along two Plexiglas rails with a dip in them, for several days.  It makes a nice conversation piece sitting on your desk.  It's very quiet in its operation.  See Patent #3783550.  From Andrews Manufacturing.  Cost is about $20.
Arbor , ScientificsOnline 31-132, AS&S , EdIn

Kinetic Chaos


This toy shows the chaotic motions a pendulum can have if it is influenced by forces other than gravity.  Makes a great toy for the executive's desk, and is silent.  From Carlisle Company, 1-800-233-3931.  Cost is about $13.
Arbor , ScientificsOnline , AS&S , EdIn

Plasma Ball


This doesn't have any magnets in it, but is it affected by a magnetic field?  Try it sometime!  From Carlisle Company, 1-800-233-3931.  Also called Nebula Ball, Sunder Ball, Lightning Ball.  Cost is about $90.  Smaller one available for about $45.
Arbor P2-7110, ScientificsOnline , AS&S , EdIn

Dynamo Flashlight

flash1.jpg (2902 bytes) flash2.jpg (5157 bytes)

Have you ever needed a flashlight, only to find that the batteries were dead and there were no other batteries of the right size anywhere in the house?  Then this is for you!  It's a hand-powered flashlight!  Simply squeezing the handle repeatedly (once a second or so) will keep the light on.  You never need to worry about fresh batteries or leaking batteries.  It even comes with a spare bulb!  The case is made from clear plastic so you can see the magnetic armature rotating, generating the voltage needed for the light bulb.  From Fascinations, Seattle, WA.  Cost is about $13.  
Arbor P3-3700, ScientificsOnline 81-554, AS&S 89643, EdIn SJ-200

The photo on the right is a similar design.  The flashlight is powered by turning the hand crank on the bottom side of the body for only 30 seconds.  It will then continue to shine for about 5 minutes.  There are two settings for the lights:  one LED or 3 LEDs.  Nice that you don't have to continually squeeze the handle.  Cost for this is about $30 from SharperImage.

"Forever" Flashlight


Here is another variation on a flashlight.  Again, no batteries are needed, and no light bulb will ever burn out.  How does it work?  Inside the handle is a coil of wire through which a cylindrical magnet can pass back and forth.  As you shake the flashlight, causing the magnet to slide from one end of the tube to the other, it creates pulses of voltage that are used to charge a super capacitor.  All you have to do is shake it for about 30 seconds.  Then, turn it on.  The super capacitor begins to provide power to the blue/white LED to give you light.  It will last for about 5 minutes.  After the light goes out, all you have to do is shake the flashlight again for another 30 seconds in order to get light for another 5 minutes.  Not bad, eh?  This one came from Brookstone.  One like it is available from Arbor Scientific and other places.  This is great for emergencies around the house or in the car.  Cost is about $40.
Arbor, ScientificsOnline, AS&S, EdIn


motion.jpg (3282 bytes)

There are several variations of this toy.  The outer structure swings back and forth, causing the inner structure to start swinging in a random way.  It may become annoying after a while.  This costs about $7.
Arbor , ScientificsOnline 81-198, AS&S , EdIn

Battery Operated Electromagnet

em500.jpg (3479 bytes) em500k.jpg (4561 bytes)

Now, this is really something to see for yourself!  It is an electromagnet, made in the shape of a cup with a central core and outer rim.  There is a very smooth plate which mates with it.  Both the electromagnet and its plate have heavy-duty hooks attached to them.  The electromagnet has places for 2 "D" cell batteries, and an alligator clip so you can power it from 1 or 2 batteries.  It is supposed to be able to hold 500lbs!  Amazing?!  I think so!  I built a stand (called "The Plank") so people can see if it can hold their weight.  Imagine, a battery is able to convert chemical energy into electrical energy, the electromagnet converts the electrical energy into magnetic energy, and the magnetic energy is able to hold the plate onto the electromagnet while a 500lb person is standing on a board attached to the plate!   From Science First (http://www.sciencefirst.com/).  There are two versions:  model 20-030 which can hold 200lbs with 1 D cell battery, and model 20-035 which I described above.  The smaller unit is also available from ScientificsOnline (Edmund).  The smaller unit costs about $48, the larger unit about $55.
Arbor , ScientificsOnline 60-435, AS&S , EdIn

Zero-Gravity Levitator

lev11.jpg (3471 bytes) lev12.jpg (3555 bytes) lev13.jpg (4160 bytes)

lev14.jpg (3402 bytes) lev15.jpg (2331 bytes)

This is a super toy!  Very new (at least for me)!  It was from www.unusualdevices.com for Discovery World.   It stands just over 11" high, the globe is 3" in diameter, and comes with is power supply which plugs into the 120Vac wall outlet.  On the back is where you plug in the power supply, there is also an on/off switch and a switch which turns on the rotating function.  This will cause the globe to rotate at a rate of about once every 3 seconds.  This is accomplished in a very clever way:   in the base are two coils, perpendicular to each other, which has a NIB magnet on edge in their middle.   When the rotating function is on, the coils cause the magnet to rotate, which in turn affects the NIB magnet which is located in the bottom of the globe, on its edge, causing the globe to rotate.  On the front left of the base is an orange knob which can be rotated, adjusting the distance between the top of the globe and the bottom of the electromagnet (which is contained in the top, pointed part of the toy).   There is a large NIB magnet in the top of the globe.  I works very well.   The globe comes apart, and an additional 1.5 ounces can be placed in the globe.    More than that will cause it not to float.  The only drawback is that when power is interrupted or the unit is turned off, the globe falls and hits the base.    One of these times, it will break.  I may need to place some padding under the globe, formed to catch and hold it if and when it falls.  It costs about $50.
Arbor , ScientificsOnline 30825-32, AS&S , EdIn

Floating Globe

This is a super executive desk top item!  Very nice looking, with a wooden base and useful globe.  The 3 and 1/2" globe comes in three different colors.  It floats about 1/2" below the head that houses the electromagnet.  A nice feature here is that if power goes out, the globe will drop and stick to the base - it won't roll off the desk and onto the floor and out the door.  There isn't anything to make the globe rotate except a gentle push from you.  It costs about $50.
Arbor , ScientificsOnline 30825-32, AS&S , EdIn

Hovering Bumble Bee

This is a new item I found at the Science Place in Dallas, Texas.  The bee will fly in a circle around the flower base when you switch it on.  It's attached to a string to keep it in place.  You can also switch on the audio of a buzzing bee, or keep it quiet (a better selection for the office).  Nice design, fun to see something new.  This costs about $13.
Arbor , ScientificsOnline , AS&S , EdIn

LED Gyroscope Top (Perpetual Top)

A surprising item!  This Top will spin (according to the maker) for about 4 hours.  It comes with 4 batteries, but only 2 are needed at a time.  It has a blue LED (obviously) and a motor built in.  This is what keeps it running so long, until the batteries finally die.  Since the instructions were in Japanese, I had to guess some things.  First, pull the top of the Top straight up by the stem to remove it.  Next, place two of the CR-2032 batteries into the hole that is uncovered, with the + side up.  Then replace the top of the Top.  It needs to spin clockwise.  It does not work if you spin it counter-clockwise.  The photo on the left is with the Top on a concave mirror.  The mirror looks cool, but also keeps it from wandering about.  The second photo is where the Top is on a concave lens that I picked up for only $1.  Same purpose.  Purchased from www.thinkgeek.com.  Costs about $17.  Great gift idea!  Here's a video on it.  How it works.
Arbor , ScientificsOnline , AS&S , EdIn

Cupid's Arrow

A very attractive wooden item!  This is like other perpetual motion contraptions where there are batteries in the base that pulses an electromagnet whenever a magnet passes by, giving it a shove.  That's what happens to the arrow that rotates and swings as seen in the photos.  But, it does more that just that.  The horizontal shaft that holds the arrow is suspended by magnets, and is held at only one point, at its tail end.  Nice design by HoverCraft (no web site!).  Reminds me of something you might see in the game Myst.  Purchased at www2.fi.edu.  Costs about $35.
Arbor , ScientificsOnline , AS&S , EdIn

Levitating Globe


A well designed item, and one that will grab the attention of everyone who sees it!  The design is very clean and simple.  No adjustments.  It just works.  It took me a few minutes the first time before I was able to get the globe to balance - my trick now is to use two hands, and keep a couple of fingers wedged between the globe and base so it won't be so strongly attracted to the side of the base, and then slowly lower it to the center position.  I found that it won't work when sitting on top of a metal file cabinet.  So, I placed an upside-down paper tray (made of plastic) under the base to give it 2"  between its base and the file cabinet.  It works very well, and is very stable.  Everyone who walks by it is amazed and wants to buy one.  When the base is covered by a piece of paper, it is even more dramatic.  The only other thing most people would like it to do is slowly rotate.  (Maybe the next model?)  When the power goes out, it will fall to the base and stick to the side of it - it won't fall to the floor, which is a good thing.  Purchased as P8-3200 at www.arborsci.com.  Costs about $89.
Arbor , ScientificsOnline , AS&S , EdIn

MOVA Globe






A beautiful, simple globe that rotates on its axis - somehow.  I did a double-take when I first saw it!  It is now a centerpiece at my office.  The design is very clean and simple.  No adjustments.  No batteries.  No wires.  No plugs.  Totally silent.  It just slowly rotates even at normal office lighting levels.  It is highly engineered.  First, the surface of the sphere seems to be the surface of the rotating globe.  It isn't.  The globe is inside a clear plastic shell that is filled with a liquid within which the globe floats with almost no friction.  Second, a set of photocells convert the light that penetrates the surface of the globe into a voltage to run a small motor.  Third, the stator of the motor is held in position by a magnet that aligns itself with the Earth's magnetic field.  Fourth, a steel band around the equator provides a flywheel affect to the smooth rotation of the globe.  FANTASTIC!  Below are some locations where you can purchase one.  I found mine at Nordstrom in downtown Seattle.  Or, Google "mova globe".  Costs about $100.  

  describes how it works

Levitron World Stage




Another well designed item.  No adjustments.  It just works - and it rotates!  It works very well, and is very stable.  The magnet can be removed from the globe and it will hover about 3/4" above the base, and rotate by itself.  It is designed so that you can place an item (less than 3 ounces) onto the magnet so that it will float and rotate.  The base has a mirror surface and blue LEDs.  The LEDs are an indicator when things are operating properly.  If you like, you can always cover the base with a cloth or paper if the bright blue lights are too much.  Distributed by www.fascinations.com.  Purchased from ThinkGeek.  Also available from ScientificsOnline and Innovatoys.  Costs about $70.  Similar unit available from http://www.levitationarts.com/.

Zeltom Electromagnetic Levitation System (emls)




This is a levitator with a feature that others don't have.  Not only will this levitate a magnet, you can control the motion of the magnet as it hangs in mid-air.  For example, the magnet can be stationary like other levitators.  Or, it can move up and down with a sinusoidal motion or with a sawtooth motion or a square wave motion.  You can also control the amplitude of the motion and the speed of the motion.  Interesting additions!   Purchased from www.zeltom.com.  Costs about $65 fully assembled with the battery adapter.







It appeared to be a nicely designed container for housing ferrofluid along with a magnet on the bottom, and an adjustable electromagnet at the top.  The knob on the side of the top allows you to adjust the strength of the magnetic field at the top of the glass jar, allowing the ferrofluid to be pulled up to the top electromagnet.  Reducing the strength allows the ferrofluid to drop to the bottom magnet.  A very expensive gadget, around $275!  The problem is that the liquid already has become hazy and has stains on the inside of the glass jar.  So, it has some real problems.  Should have a cost of $50.  Buyer beware on this one!  http://www.ferroflow.com/