Picture of How to make your own Metal Pulse Magnetizer
Four weeks ago I was searching for an magnetizer that can revive my dead magnets (I killed them heating up at a high temperature, trying to encapsulate in a piece of glass), but I haven't found a instructable project that can help me, so with physics teacher's support  I made one that works.
With it's help you can revive dead or old magnets, or you can magnetize things like screwdrivers, nails, paperclips, or any metal which can be a good magnet.
It looks like a game console, isn't it ?
This device is only a PROTOTYPE, so maybe I will try to make a big one that can magnetize your hammer.
Now let's start the work.

Step 1: Materials

Picture of Materials
The materials you need for this project are:

- a 1N4007 diode
- a DPST switch (I get mine from an old computer)
- a Push button switch (or how it is called)
- a jack and a capacitor(230 uF and 400 V) from an old power supply unit
- a plastic, wood, Plexiglas, or any material you found, but NO metals like iron, steel, aluminum, copper or any metal that are atracted
by magnets.
- a 15 W, 220 V lamp
- copper wire for making a coil (0.6 mm diameter for 800 turns)
- something on you can spool your coil (I use a plastic support from solder with inner diameter 20 mm [don't use something that have the inner diameter bigger than 20 mm because then your magnetizer will not work])
- a cable for your jack (I use an ordinary cable for PC supply), why I use it ? because it can be removed.
-two plastic panels (I made them because my case needs panels )
- 20 cm of thick copper wire (2-3 mm diameter) 
Watch out how you handle the capacitor. If it is charged, and you touch it, you can die.
Try to make the capacitor's links with push button switch and with coil as short as you can,
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Plastic switches, no through the box metal hardware, no conductive issues for electricity to exit the box go tell undrwiters cie ...
That is true, but a fuse isn't there to protect you. You need a fixed or portable RCD in order to effectively minimize the risk. Putting a fuse in will only help protect components an wire.
I stand by my original statement. This is a prototype, not a professional product.

Can we please start encouraging the author rather than deriding him?
You've got this all wrong. The OP just wants to raise awareness for the Darwin Awards. Seriously, if you manage to kill yourself making this, it's your own damn fault.
trekman2 years ago
How will the circuit change for 120 volt as the input voltage? Will the Diode, coil and the Cap be different?
Build it based on the existing circuit specs. Use a local 120VAC bulb instead, and double the size of the capacitor.
minimax2 years ago
There are no safety issues. The lamp limits the current through capacitor and coil. There are no shorts! No need for fuse. Even the capacitor fails, the lamp will glow normally.

You can keep the device connected to mains indefinitely: the capacitor will stay charged until you push the discharge button.

Ferromagnetic materials are in fact ATTRACTED to the center of the coil: they vibrate and stuck in the center. Only magnets can be thrown outside or inside, regarding the alignment of the magnet poles.
Firstly, there is always a risk when using mains. what happens if you get a short before the Light bulb?

The problem isn't always shorts, insulation breakdown and leakage to ground (through people) is really the concern.
Oh I forgot to mention you can die from 50mA across the heart, The light bulb will only limit it to 60mA. I may get reported for this. But please don't go commenting on stuff which is potentially life threatening. 220V light bulb at 60mA is more than enough to kill you.
Do you have a desk lamp? Is it fused?
No, but if I did it would be fused at the swithboard... Most houses have fuses. Just saying. Also a desk lamp is of better construction and also needs to comply with certain safety standards. At least in my country anyway.

Fuses will only protect wires and equipment, use this set up with a tested RCD and you will be fine.
AlpineLED2 years ago
Now that I'm looking for to magnetizes some of my hand tool like screw drivers of different size. I like your design only when using 120 volt. I need to build this as strong enough to hold any metal screws. So the drawing I see are for 220 V. How can I make this out of 120 V? I would like to add LED light to recognized it is on. How long can I leave it on before I turn off? Secondly, would this be possible to use transformer then convert it to DC would this give stronger magnet? Your advice I greatly appreciated to help me build this project. If you or anyone to make schematic drawing
sample I want to build it from 120 V that are easy to use and put away are lighter to handle than that of heavy batteries.

Andrey, Great job on your prototype project of your simple design.
There's aways plenty of newer ideas on your next projects and your positives will have better results!
alzie2 years ago
These are very cool, nice job!

I d built a low voltage one years ago.
It runs off of 12 - 24Vdc, (a car batt charger works well)
uses three 40,000uF computer filter caps,
an auto brake bulb for charging,
a Big 30A SCR for dumping into the coil, and
a 30 turn #12Ga coil to magnetize.
You trigger the SCR for a pulse,
no contact erosion.
Its non resonant, so
demag isnt an issue.
No HV, no danger.

It will shoot bolts across the room.
Much fun!
nuckollsr2 years ago
Oh yeah, I forgot to add to my earlier posting . . .

The largest hazard to your person and property in working with this project is making measurements.  With no isolation transformer in your ac mains supply line, there is risk for hazardous fault currents to flow when you attach your 'scope to the circuit under test.

If you're planning to expand your studies, see if you can acquire a small isolation transformer to use between your test circuit and the ac mains.  I note further that you specify a 220v lamp. Are you working with 240 ac mains?  If so, your capacitor will charge to about 1.4 times the rms line voltage or about 340 volts dc.
incorrect on the charge votage of the cap. there is a half wave diode in the input. the charge voltage of the cap will only reach .707 x rms -.7 v input voltage....
The scope was connected with a small probe-coil (ten turns) inserted in the magnetizer channel.
I think this is a great project, but I'd make it more powerful!
Seems a lot of the comments are bandying misconceptions about.
Both switches closed together - all that will happen is the lamp will glow
Fuse - isn't there one in the mains plug?
Voltage across capacitor - this won't be half the mains voltage, it will be near the peak voltage, which is 1.4147 x mains voltage - about 350 to 380 volts dc.
Oscillation - a valid point, but as someone else said, most of the energy is dissipated in the initial discharge. A high voltage diode in reverse across the coil would kill the reverse emf.
The only failure condition which could expose the user to mains voltage is a broken or open box. I don't agree with the "what if" scaremongers. Televisions (crt type) never used to have an isolation transformer and some voltages inside the case were much higher than this, and the back cover only made out of some kind of board.
Capacitor holding it's charge when the unit is off - a good point. It would be better to have a "bleeder resistor" connected across the capacitor, this will slowly discharge it if you forget to push the button.
I agree you should have some sort of indicator to show it is switched on/plugged in. Why not use an illuminated rocker switch for S1?

You should probably make a proper mountings though - all glue will fail eventually. Make sure any screws which go through the case are earthed.

Good stuff andreyeurope - keep on building and be safe!
your comment about the peak voltage is inncorrect. Because the half wave rectifier is on the input, the voltage can only reach 1/2 rms due to the coil, (diode limits voltage to peak, coil acts as a filter limiting it ti the rms value) basic power supply precepts are used here.
Oh one other point, the capacitor used is extremely lossy, hence no need for bleeders which would reduce efficency and require a larger cap to ocercome the RC time constant issue that would be created
minimax prazape2 years ago
The oscillations are hyper-damped by coil resistance and capacitor ESR.
..I like that man ..congratulations..bright ideas are always simple..
andreyeurope (author)  sergiosparks2 years ago
Thanks Sergiosparks.
gafisher2 years ago
Nice project, Andre, and a good 'ible. Your Physics teacher sounds like one of the good ones too. Don't be discouraged by the negative comments; wiring an extension cord or a light switch requires as much common sense as building your magnetizer. One tiny suggestion I would offer is to replace S2 with an SPDT switch so that the coil can never connect directly to the charging circuitry.
andreyeurope (author)  gafisher2 years ago
Thanks Gafisher.
Edgar2 years ago
Neat! :D
Voted, and Blogged:
andreyeurope (author)  Edgar2 years ago
Thank you, Edgar.
Damn this is cool. Thanks for explaining it in a simple way that non-electronics people can understand.
andreyeurope (author) 2 years ago
Like I SAID, this is just a PROTOTYPE.
Next step for me is to produce a stronger magnetic field using many small capacitors, so like this you can't DIE.
Thanks those that encourage me and the ones who try to help me.
nuckollsr2 years ago
Good first steps! The complaints about fusing and insulation are not well founded. There are countless tools and appliances that shed their government mandated third grounding prong on a wall plug because added insulation demonstrated a vanishingly small risk. Same thing about the fuse . . . a failure modes effects analysis of your circuit shows that worst case outcome for any component failure manifests in a stable, benign condition.

Your 'scope trace picture is not necessarily 'invalid'. When you connect a low impedance voltage source to an inductive load, Current flowing at time zero+microseconds is very close to zero amps and it climbs as the counter-emf generated by a decaying rate of rise in magnetic field decays. Capacitive loads are the mirror image where time zero+microseconds currents can be very large.

Refinement of your design might concentrate on configuration of the magnetic circuit. A great deal of magnetic flux generated by your coil is allowed to circulate in air and does not add to the magnetizing forces for the target material.  See:


Years ago, I worked for a motor manufacturing operation that bought 'discharged' rare earth magnets for use in our products. After installation, they were 'charged' by a process similar to what you've demonstrated . . . but with much larger energy numbers. Our bank of capacitors was 100,000 uF charged to many hundreds of volts.

Design of the coil and magnetic flux conductors was critical to maximizing the concentration of flux into the target material. I'll suggest that some refinement of your technique for concentrating flux into the target will produce a marked jump in efficiency with the electronics you have.

Fiddle with your 'scope setup . . . trigger on initial current rise and figure out how to get secure meaningful energy measurement of the pulse. Flux intensity is proportional to amps x turns. Time is of little relevance . . . it's the peak current that does the trick. You may find that fewer turns gives you a higher AT product. You're on the the right track and the opportunities for learning are great.
darksb3r2 years ago
Lol..."Tips: Watch out how you handle the capacitor. If it is charged, and you touch it, you can die."

Nice tip there.
Indy_Rider2 years ago
Very nicely done, and for the negative comments, just ignore them as most of them probably would freak out if they actually looked at any of the lamps in their houses.
Orngrimm2 years ago
Cool idea to use the lamp as indicator when the cap is charged!

Also as a hint: eBay often has 400v 470iF caps on sale. I got all mine from eBay. :-)
Ugifer2 years ago
I really like this project but I think there are a couple of related issues that are important:

Firstly, it would be quite easy to press the toggle switch forgetting that that the DPDT switch is still "on", particularly because the light goes out once the capacitor is charged so there is no reminder that the mains power is still on. You could really use a mechanical (e.g a sliding cover) and/or electrical (e.g. normally closed relay) method to prevent the toggle switch being pressed when the mains power is on. Otherwise you are in for a large bang.

Secondly, I would say that a fuse is very important because if you did short the coil across the mains by activating both switches then a fuse would limit the decimation somewhat. Your 15W lamp will only draw 60mA so a 100mA fuse seems like an essential safety feature to me.

A great idea and nice result but a little too much "bang" potential for me as it stands!

andreyeurope (author) 2 years ago
First, the items aren't throw out as a gun "throw out" it's bullet.
When you finish using this device, you stop the power supply and then push the buttun of s2 switch and the capacitor is empty.
If you zoom a photo you can see that almost all links are insulated, and for sticking i use a lot of HOT GLUE which is solid when is cold.
I don't use a fuse because my circuit do not require it.
Outside of case aren't any wire so I think it is safe enough.
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