Microwave Oven Transformer High Voltage Rig

Intro: Microwave Oven Transformer High Voltage Rig

For my first Instructable, I decided to make a high voltage power supply out of 2 microwaves. The videos should give you good idea of the final product (I'm using only one of the 2 transformers):

STEP 1: Disclaimer

This circuit gives off more than enough power to kill you. I am not responsible for any injuries you may get from doing the following steps.

STEP 2: What You Need

Most of the stuff you need will come straight out of a microwave, so see Plasmana's instructable, but you will need:

• 2 Microwave transformers
• 2 Safety switches
• 2 125V 15A fuses and holders
• 2 Grounded plugs
• Random wires that you can get out of the microwaves
• Something to mount the stuff onto (I used scrap 2x4)
• At least 2 friends - one who knows CPR and one that can call 911 NEVER DO HIGH VOLTAGE EXPERIMENTS BY YOURSELF

STEP 3: Mount Everything

Simply place the parts in an orientation so that you can wire it up easily. Then drill the transformers and fuse holders onto the 2x4 and nail the safety switches down.

STEP 4: Wire It Up

The circuit will be wired in series, giving you an output of about 4kV. I decided to use 2 plugs to make sure I don't set the wires on fire :D. You can wire the rest up according to the schematic below, if you can't read it, you shouldn't be making this. To get out the most power, attach the 2 HV Out wires together and touch them to ground. Tip: before attempting to ground anything, scrape off enough varnish to have a good connection. Caution: This setup is un-ballasted, and the transformers can heat up very rapidly. Use this only for short periods of time.

STEP 5: Power It Up!

Carefully, wearing non grounded shoes, holding non-conductive rods to push the switch, press the switches and hold them. Don't look directly at the arc without eye protection, it is close to the brightness of a welder. You should now have a spectacular arc to show off to your friends and family!

STEP 6: Random Notes

• I purposely put the 2 safety switches on opposite sides of the 2x4 to prevent me or anyone else from turning it on by themselves. Also, to keep the board from breaking under the ~12 lbs of transformer, I made it as short as possible.

Update as of 3/5/09:

• I decided to ballast the first transformer with the second, schematic is attached

STEP 7: Update: Neater and Safer

I decided that I could find a better and more presentable base for my project than scrap 2x4, so I reorganized everything onto a piece of Formica giving me space for at least two more transformers. Also, it is more easily troubleshoot-able and modular

Comments

[goldenshuttle]

If we connect the 2KV output of transformer 1 to the input coil of transformer 2 will this give 36KV at output ?

[chicks540]

no it gives you fire when you burn up the primary windings. But for an instant maybe yeah? sounds pretty dangerous though. I don't recommend. 4kv is crazy a lot 36kv might just jump back and grab you then you'll be thankful if the primaries burn.

[tony54]

Use an old NEON SIGN TRANSFORMER INSTEAD, MUCH SAFER ! Don't build this to play with, only if you are experienced with electricity and VERY COORDINATED. Your first mistake could be your LAST MISTAKE ! If you insist on trying this at least put SEVERAL RESISTORS IN SERIES TO LIMIT THE CURRENT IN CASE YOU DO COME IN CONTACT WITH THE HIGH VOLTAGE. Also, make sure to GROUND THE CASE (AND THE TRANSFORMER) TO EARTH GROUND. Microwave transformers use one of the HV leads connected to the transformer case which is EARTH ground in a microwave. Use many 10w or higher to total 300,000 ohms which limits the current to 5ma (1500v / 5ma = 300,000 ohms). It takes about 5ma to POSSIBLY stop your heart. Still not safe but a big improvement. Also, space out the resistors several inches, the HV will want to arc across them.
As for putting a light bulb in series with the primary, it's a good idea but use a LOWER WATTAGE BULB. A 100w bulb would be 144 ohms when drawing power.
5w = 2880 ohm
would be, 120v / 144w = 1.2 ohms. Not much resistance.
Use Voltage squared / Watts to find the resistance since it can't be measured by a meter since it changes. Or just use a large normal resistor but the high power ones are more expensive and harder to find.
I would use the 5w myself, ONLY INCANDESCENT WILL WORK, Fluorescent or CFL will probably just burn up.
This will ONLY protect the transformer and reduce the power draw, it's still can easily kill you! Use a TV flyback based project so if you get bit, it will just hurt! But the jerking still might cause you to get cut by running into something else!
If you aren't EXTREMELY CAREFUL use a neon sign transformer, you can get MUCH HIGHER VOLTAGES much safer. Or a TESLA COIL.
P.S. The average microwave transformer can put out AT LEAST 1A, possibly 10A or more upon shorting. Wear sunglasses if you need to look at an arc or WELDING GLASSES if you weld. Unless you like using a cane instead of eyes.

You can use this to calculate the resistance.
http://www.ohmslawcalculator.com/ohms-law-calculator

[69buickgs]

Yeah, and 5mA won't COOK your internals.

[tony54]

And no it won't cook you but it will give pretty severe burns and if you get good contact, body resistance can get aybe down to 100 ohms thru your body, that's 16mA but it can get much lower with sweat so a higher amperage and people have been killed by even 42volts DC like the Ohio State Physics dept points out!
120 volts is the most common voltage that kills people and this is probably 1600 - 2000V AC since the body isn't much of a load compared to the 10 - 14 magnatron so it might put out a little higher voltage. I saw an instructor shocked one time and he jerked so hard he hurt his back and was shaking for about 30 minutes because of the pain and probably nervous system effects.
Stun guns that are "safe" have also killed about 300 people worldwide by messing up their heart rhythms. Some immediately and some came several hours later. I'm guessing it messed up the heart-brain connection so the heartbeat will go slower and slower until it stopped. But that's only a guess but probably on the right track like people that have implanted pacemakers that fail so their heart slows down until they die from lack of blood flow and therefore oxygen to the brain. Still, possibly LETHAL! It isn't just safe under the 100mA, it make a huge difference how far from the heart and brain the electrodes are, lenght of time, and how good of skin contact. And high voltage can poke right through the outer skin layers into that electrolyte we call blood. Blood is the same ph as sea water and full of salt, so it's a pretty good conductor!

FATAL CURRENT - Ohio State University Physics
https://www.asc.ohio-state.edu/physics/p616/safety/fatal_current.html
Unless it's a high impeadence source, I wouldn't play around with it!

[GarethT7]

No, but about 30mA can ! Under the right conditions and about 10mA can kill livestock.

To be honest, being a professional industrial electrician, I am amazed at what is going around this place.

Agenda 21 in full effect I guess ;-)

[The Freak]

That should be voltage squared devided by power. So 120V^2/100W=144Ohm etc.

[M2aestro]

Please don't depend on sunglasses to protect you from arcs. The one you generated could be too much for the attenuation of the wavelengths resulting from the arc. Possibly multiple layer filters, such as the semi-rigid film eye shields used by many senior outdoors, but worn over sunglasses would be safer? Also, please don't allow the arcs to be viewed by an audience that does not have adequate protection.

[rik3098]

i never new aplug could be grounded whats it grounded from tv,computer,wii???LOL

[Count Volta]

Tv,I think.

[BdSquirrel]

This would make a good squirrel (or other pest) trap, provided you monitored it and only connected it to administer the pentaly.

This is also a good way to get someone killed. Even if the electricity doesn't cross your chest and stop your heart, touching any other part of your body will cause violent muscle contractions which could cause broken bones or other injuries. I won't even mention the serious buns and tissue damage it will cause!

[supreme_clientel]

Lol... "buns damage".
I know what you meant....it was just a funny thought.

"....I dunno, I went outside to play with my transformer and the buns just exploded! Well just do pizza."

-"Dude, what's wrong with your shorts!?"
-"Doc says I got wear this bandage for a month. I was playing with my transformer and caused serious injury to my buns".

[einyaa]

Just be aware of that the current from a MOT (microwave oven transformer) can KILL YOU in an INSTANT ! Unlike the misunderstanding that the higher the voltage is, the more dangerous it is, it's the current flow (especially at 50 and 60Hz) which kills you. The frequency of 50-60Hz is also contribuing to an cardiac arrest (atrial fibrillation) of the heart. Tesla coils on the other hand, is not so dangerous at the HV-side because even if it is hundreds of kilovolts output, the current is very low. Also the frequency is very high, and will not pass through the body but only on the surface of the skin. It can burn yes, but will not pass the heart.

A typical MOT delivers 2000 volts or more output, and currents up to 500 mA. Ten times higher than the current necessarry to stop your heart.

Again - playing around with MOTs requires a deep understanding of the dangers it represent. Always have another person with you when experimenting with high voltage. He/she may disconnect power if an accident occurs.

[crazy-blender]

I believe you wired this wrong. to wire it correctly you must connect the cases together and ground it then arc between the 2 HV out wires. if you want more power you can wire 2 microwave oven transformers in series as a half-resonant circuit or better yet wire 2 in series in parallel with 2 more in series and connect them like this:

[crazy-blender]

:

[KrishenM]

Nice schematic. Shouldn't you have a ballast to keep it from over heating though? Although I think the ballast in step 6 of the main post is wired incorrectly. I think it should be in series with the output. No?

[69buickgs]

My next step. Only have two for now though. Just have to do a little more searching. In going to start trolling the alleyways around the student housing areas at the local colleges for discarded microwaves.

[crazy-blender]

Ignore the PFC capacitor you don't need it to work. The ground connection is in the middle. As I said before connect the cases of the transformers together and ground them. draw arcs between the 2 HV outputs.

[69buickgs]

What's the max current/voltage anyone has tried to put into the MOT secondary without a meltdown?

[muttyfutty]

I currently own an MOT and it is working fine, except for the fact that the primary windings get very hot during operation (after 10 seconds of arcing) I am connecting it directly to the Mains (240V) I have mesured the imput (Mains current) to be 10A ++ Is there any way to limit the input current to prevent heating in the secondary windings On another note, is it possable if I had 2 MOT, to connect them in Parallel in order to get greater ampage output, and if so how Sorry for the long question! :) Thanks in advance! Mike