America's Got Talent TV show Idea

I have an idea for America's Got Talent.  Take several of my devices and fire them all off at once, with some music in the background.  Here is what my setup might look like.

The first thing I am going to make is a double headed Tesla coil. I have two 2 foot by 4 inch coil forms for the secondary. My old "big coil" used a three inch pipe.  Here is a picture showing the new forms compared to the old ones.

I have made a new top load with 4 inch flexible duct glued to an aluminum pie plate.

Then I will make my washer launcher into a double headed model to launch two washers in rapid sequence. I may add LED's to the washers to make them look like UFO's as they fly through the air.  Here is a picture of me making the new flat coil for the launcher.

Next in my vertical can crusher. I have two 15uf at 5KV capacitors to add to it, they will replace the Defibrillator capacitor, they are 4 times the size of the defibrillator capacitor.  Its going to be hard to fit them in the case!

Also new is the idea of adding some soda can launchers. They will use some 3 inch PVC pipes to fit the soda cans.

Electromagnetic Coil Devices

Electromagnetic Coil Devices.  We make two models of Pulsed Electromagnetic Coil Devices.

Super Thumper - Sold Out.  This device produces a 300 volt pulse of up to 100 Amps into a 3 inch coil of around 50 feet of Enameled 14 gauge wire.  It has a power transformer and a voltage multiplier to produce the 300 volts.  It takes about 5 seconds to charge the capacitor bank to 300 volts.  The capacitor bank is 8 x 390 uF at 400 volts. 

Low Power Doug Coil - Sold out.  This is modeled after the Doug Coil setup but it is a lower power version.  Basically a frequency generator feeds a Power amplifier that feeds a Capacitor bank that feeds a Coil.  The frequency generator can be a professional device or a computer program can makes any computer into a frequency generator.  The Power amplifier needs to deliver 100 volts peak to peak or be able to handle about 250 watts and it needs to be able to drive a 2 ohm load.  This is very demanding and usually a QSC amplifier is used.  The capacitor bank consists of a box having 6 switches and combinations of 400 volt capacitors to give .5, 1, 2, 4, 8, and 16 uF.  The coil is made from around 500 feet of 14 or 12-gauge wire.  It can be enameled or insulated wire.  The picture shows a switch box, a 14 gauge enameled coil as well as a 12 gauge insulated coil.  Amplifier and signal generator not included.

Super thumper my latest revisions.

My super thumper has been redesigned once again. The 24 volt AC adapter took 15 seconds to charge the capacitors so I went back to using a power transformer and reduced the charging time to 5 seconds. Note the use of a plastic lid to cover the coil.

Fitting the power transformer in the smaller cabinet was tricky but here it is all fit nicely in the instrument case.

Its up for sale for $250 and I might list one on Ebay to help sell them.

Stuff to sell

I am selling a lot of my stuff on Ebay. Look on Ebay under bob_davis321 to find my stuff that is for sale.  My email address is bobdavis321(at)gmail.com  Make sure yo replace the (at) with @ so it will work.

Besides the stuff on Ebay I am also selling these three things;

1. Sold - My 'Super Thumper', washer launcher or 'Electromagnetic pulse device' based on the Bob Beck design.

2. Sold - My Improved 'Doug Coil' device with the capacitor switch box (QSC Amplifier is NOT included)

3. Sold - My 24 KV Power supply that is used for a Rife Tube driver (Rife tube is NOT included).

All of my devices are improved, cheaper, and simpler than the original designs.  For example the Super Thumper runs off an ac adapter making it much safer electrically.  The 'Doug Coil' uses 14 Gauge enameled wire making it much more powerful than when you are using one that is made with insulated wire.


Here are pictures of version 3 of the Super Thumper that is up for sale for $250, first a picture of the insides. 

 Then what it looks like on the outside, note the 24 VAC adapter on the left to power it..

I am looking for a cover for the coil to make it look nicer.  A mayonnaise jar lid might work nicely. Here is an updated schematic.  The input is 24 to 30 VAC at 1 amp.  Sorry that the schematic is so small, you can click on it and then it will get bigger.

Super Thumper Specifications;
Capacitor bank: 8 x 390uF at 400 volts
Power source: 24-30 VAC at 1 amp
Voltage Multiplier: 4 x 4A bride rectifiers and 7 x 220uF Capacitors.
SCR: Minimum 100 Amps at 400 Volts
Coil: approx 50 feet 14 Gauge enameled wire 3" in diameter.
Coil plug: 4 pin Cinch-Jones connector
Wire to Coil: approx 5 feet of 16 gauge stranded wire
Box size: approx. 8 inches by 6 inches by 2.5 inches

The Doug Coil Setup, the Capacitor is in a switch box to select the correct value.  I will include the coil and switch-box.  You can use a frequency generator program on a computer and the QSC amplifier can be purchased on Ebay.   I hope to have pictures soon. It works with as little as a 100 watt amplifier but a 250 watt model is highly recommended.  The QSC amplifiers can run into a 2 ohm load so they hold up better when running a coil that is only 1 ohm!

Here is a picture showing a 'normal' green Doug coil (I have 2 of them), my smaller coil (14 gauge enameled wire 9 inches in diameter) that is many times more powerful even with a smaller amplifier) and my switch box. The switch box I am selling is smaller (around 8 inches by 6 inches) and only has 6 switches on it.  Normal Doug Coils are made with 12 gauge insulated wire and they are very hard on your amplifier.

My modified Doug coil specifications;
Coil: approx 500 feet 14 gauge wire (enameled or insulated)
Wire to coil: approx 5 feet of 16 gauge stranded to 1/4 inch plug
Switch box: approx 8 inches by 6 inches by 2.5 inches
Switch box jacks: 1/4 inches input and output
Capacitors: Non polarized 1/2/4/8/16 uF at 400 VAC
Switches: 15 amp SPST switches

Capacitor values for several frequencies;
300    32
400    18
500    11.5
600    8   
700    6
800    4.5
900    3.5   
1000    3
1100    2.5
1200    2
1400    1.5
2000    1

Last of all is my 24KV Power supply.  Here it is shown running a Rife tube.

 Here is a picture of the guts.  The unit for sale is about 1/3 this size.  As you can see there is a lot of extra space inside.

Super Thumper rebuilt again

I was using my 'thumper' the other day and the diodes shorted out.  After looking at the schematic I realized that the diodes were taking the full force of the reverse EMS off the coil.  I changed the schematic to fix that bug.

Also I was able to purchase on Ebay about 50 of 390 uF 400 volt capacitors.  Thats enough to build five of these devices.  Here is what the rebuilt one looks like.

This is what it used to look like before I rebuilt it.

I hope to build another one that will use a 24 VAC AC adapter to power it.  This change will make it even more electrically safe that the current setup.

2000 Volt Washer Launcher/Can Crusher

My old 8 capacitor power supply is back in action!  This time it has 10 capacitors, and delivers 2000 volts at 1600 amps from 1,600 uF of capacitors in a series/parallel combination.  The old 5 watt resistor was replaced with a 50 watt resistor!  It still smoked when it was powered on, likely from the grease from my fingers.

The video is already up on YouTube.  It is at: http://www.youtube.com/watch?v=i87EuYIQO9c

I tried crushing three soda cans at once, a free launch that went way out of site, and upset the neighbors, you can hear them saying "What was that?" and then I crushed one soda can.  Not included in the video is another free launch where I lost the washer.  It was found later over 100 feet away on the far side of the house.

This is the schematic diagram.  There is an error, the capacitors are only 4700 uF!  The 'fire' resistor is 1K, and the meter resistor is 2.5 meg ohms, that value varies with the meter that is used.  There is also a 10 amp fuse on the power coming in, it is built into the power jack.  The coil is a flat coil of 14 gauge enameled wire covered in a lot of glue.

Tesla Coil Gossary

Tesla Coil Glossary by Bob Davis

Tesla Coil – A collection of coils and wire designed to make great big sparks
• Spark Gap Tesla Coil – a Tesla coil that uses a spark gap to switch the power just like Tesla did.
• VTTC – Vacuum tube Tesla Coil – One that uses vacuum tube(s) as the switching device.
• SSTC – Solid State Tesla Coil – An oxymoron as these things were never designed to do that.
• IGBT – Another type of SSTC but usually a little more successful at working without self destruction.

Transformer - device used to convert the main power source to something that will produce big sparks.
• NST - Neon Sign Transformer - Normally used to light the beer signs in bar windows but also used to make big sparks.
• OBIT - Oil Burner Ignition Transformer - Normally used to start a fire in an oil fed furnace but can also produce big sparks.
• MOT - Microwave Oven Transformer - Normally used to cook your food but it can also cook you.
These normally do not produce long enough of a spark but they can be wired in series or used with a voltage doubler.

Capacitor – Device used to store a charge then release it to produce bigger sparks.
• Paper capacitor – Aluminum foil and paper arranged to make a capacitor.
• Door Knob Capacitor – Big capacitor that is shaped like a door knob, usually these can take a lot of volts.
• Home made capacitor – Old beer bottles or whatever used to make a home made capacitor.
• MMC – Many, Many Capacitors - arranged in series or series/parallel to make one big capacitor.

Spark gap – Favorite part – makes sparks what else? Sometimes self-destructs.
• Fixed Spark Gap – Two things that sparks fly in between – sometimes intentionally.
• Multiple Spark Gap – Several spark gaps arranged in series, usually air cooled too.
• RSG - Rotary Spark Gap – Motor driven rotating spark gap, runs cooler as power is only on for a ‘short’ time.

Coil – Sometimes just a pile of wire but it should be neatly wound in circles to look good.
• Primary coil – Flat or angled coil of large wire that creates the primary magnetic field.
• Secondary coil – Long coil of fine wire used to pick up the magnetic field from the primary, many, many turns but it looks neat of wound properly.
• Choke – A type of coil usually wound around a ferrite core and it is used to stop RF noise.

Top Load – Anything from an aluminum plate to a large torroid used to store the high voltage until it arcs over and makes big sparks.

My big Tesla Coil revisited

Recently I dug out my big Tesla Coil and decided to update it and make it better.  Some changes I hope to try are a bigger top load, try two capacitors in parallel and make an angled primary coil.

First of all here is the current schematic.  I realized that I had never made a schematic for it.

Here are some pictures of the guts. First we have the Neon Sign Transformer or NST.  It delivers 12KV at 30 ma.

Next we have the spark gap.  It consists of 5 pieces of 1/2 inch copper pipes spaced about 1/8 inch apart inside of a 4 inch PVC pipe with a fan blowing air down them to cool them and to quench the sparks.

Then we have a front view of all of the guts.  The safety gap is the closest item, the transformer connects across it.  Then on the right and left are the choke coils.  Between them is the .06 uF 30KV capacitor and in the back is the spark gap assembly.  Above that you see the primary coil made from #10 electrical wire.

Now for a picture of everything at once.  The secondary coil is wound on a piece of 4 inch PVC about 28 inches long.  The top load is some flexible 3 inch drier vent pipe glued to an aluminum pie plate.

The video is uploaded to YouTube.  The sparks are about 15 inches long.  It used to do nearly 2 foot sparks.  I am not sure why the sparks are smaller.
http://www.youtube.com/watch?v=3rwQZdZYdss

Cold Nuclear Fusion Revisited

Many years ago I came up with the idea of crossing ‘gas plasma electrolysis’ with ‘sonoluminesance’. My hope was to get ‘sonoluminesance’ and ‘gas plasma electrolysis’ to both take place in the same jar. Both are hard to start but my hope was that by combining them it would be easy to start. There were several problems to overcome. Like for instance, the frequency of sonoluminesance changes with the temperature of the water. So I was not able to get it to work. Maybe someone out there can get this idea working.

http://sites.google.com/site/bobdavis321/high-efficiency-devices

Think of all the energy we can save if we can easily produce hydrogen from water? We could end our dependence on foreign oil. We can stop tearing up the landscape in Pennsylvania trying to extract the gas from the ground. This idea really could save the world!

Ionic Spinner

One of my inventions that I have been working on requires the use of an 'ionic spinner'.  I had seen one of them several years ago made by the son of a friend who lives in southern Texas.  I asked him to put it on YouTube but alas I could not find anything about it anywhere.  So I tried making one for myself but it does not work so far.

Basically the idea is to take some needels and mount them in opposite directions on the ends of a wire that has a loop in the center that goes over the top of a Tesla Coil or similar high voltage device.  Then when the high voltage is turned on and sparks fly off the ends of the needels the spinner starts rotating in circles.  Turn off the lights and you have a very nifty picture.  So I will keep working on it and hopefully post some pictures of it running some day soon......

It is up and running, although it is not working all that well.  There are two videos uploaded on YouTube already.  video1  video2
video3

2400 Volt Can Crusher

This is an old post that somehow made its way to the top?  It is from the summer of 2009.

I could not leave the idea of vertically crushing a soda can into an hourglass shape, so that is what I am working on next. This power supply will hopefully deliver 2400 volts. The problem is that I do not have a SCR that can handle 2400 volts. So some sort of mechanical contacts will have to be used. They may have to be replaced after each use.
This cabinet was purchased last June at the Rochester Hamfest for $15 I think. The front will have a digital meter, and connectors for power and ground. Note the size of the 470 ohm resistor, it is rated for about 250 watts, no more smoking resistor.  The panel meter is connected to a 1 meg ohm resistor that is in series with a 9 meg resistor, not across a capacitor like it shows in the schematic.

5 KV Soda Can Crusher

The 5 KV power supply got a big boost when I won a complete power supply on eBay for $100 including a 5 KV transformer, 100 uf Capacitor and a contactor. There were a lot more parts in there but I did not need them. I rebuilt it and almost split a soda can in half on the first test run. The video is on YouTube under bobdavis321 but I cannot get the link to copy right now. Then I tried to use it again but discovered that the power transformer was shorted and the diode was blown to bits. The problem was that there was no resistor to limit the kickback current.
http://www.youtube.com/watch?v=DocVqsdDQG8
So I rebuilt the power supply using the schematic of the other 5 KV supply. This time I used a resistor to limit the charge current and to protect the diodes during discharge. The schematic is shown below.
To test out the rebuilt power supply I used an apple and then a pumpkin. The apple was soft and mushy but it blew to pieces at 5 KV. The pumpkin did not blow up at all. So I filled it with water and tried again. There was a big bang but the pumpkin survived. After several tries it did split wide open as is seen in the picture below. The video is also on YouTube.
http://www.youtube.com/watch?v=RSYTqCBXRmE

Electromagnetic Pulser - Zapper Revisited

My electromagnetic pulser or zapper died recently. To be honest I only use it about once a month to treat some aches and pains. When I opened it up I discovered that the current limiting resistor was disconnected, the push button was disconnected and several of the capacitors were unsoldered. The main problem was that the capacitors were not all glued in place. Movement and vibration led eventually to them becoming unsoldered.

Since I had to work on it anyway I thought that I would upgrade it to meet UL standards. That includes adding a power transformer, a fuse, and some other odds and ends. The primary requirement is that it be 'double insulated'.


One of the first test runs of the rebuilt zapper started in Africa. I accidentally fell into a storm drain. That resulted in a black and blue foot and hip, a scratched up arm and hand. At first I just wrapped the foot, but I still could not walk. So I added a high power magnet into the wrap and within an hour I could walk on the foot. As soon as I got home a week later I used the zapper and it reduced the pain in my foot by about 80% immediately!

24 KV Power Supply

Years ago I wired up a quick 24 KV power supply. However I never got around to putting it into a nice little box. Well that finally is done, it is in a cabinet. However it did not work when I tested it out, I had to change out the Power FET to get it up and running again. So with it working, I wanted to see if I could get a spark to travel around in circles in the presence of a magnetic field.

After playing around with the magnets I also tested out a Rife tube that someone had given me. It was just sitting in a cardboard box while I tested it. Then I also tested out a big U shaped argon tube to finish up the latest experiments. The video is up YouTube somewhere.
http://www.youtube.com/watch?v=19hcqKzOlBI

I drew up my schematic and posted it here on my blog. This schematic design was borrowed from one that I had found somewhere else on the Internet. You could easily use a 24 volt center tapped power transformer or a 12 volt transformer with a full wave bridge rectifier. I have used several power FET's with little change in the performance. They can be removed from a sick computer power supply.

5 KV Soda Can Crusher

I purchased a defibrillator capacitor on EBay and have upgraded the old 2.4 KV can crusher to a 5 KV can crusher. I added a voltage doubler on the output of the Microwave Oven Transformer (MOT) to get almost 5 KV. The defibrillator capacitor is rated at 30 uF at about 5 or 6 KV. Can you imagine hooking that up to a person?


The video is now up on YouTube at: http://www.youtube.com/watch?v=SbjXFbuCvqE

Here is the guts that are inside of the 5 KV Can crusher. The 1 uF 2 KV capacitor that was removed from a microwave oven is mounted on a piece of plastic to insulate it from the chassis.
Here is the schematic of the 5 KV can crusher's power supply. The 10 Meg resistor in the voltage divider fried because it could not handle 5 KV. So I replaced it with 10 x 1 Meg ohm resistors. Technically I think it should have been 9 x 1 Meg ohm. The defibrillator capacitor was only 30 uF, I wanted to get a 100 uF capacitor that was on sale on EBay for $150 but the price was a little high.

By the way, I do not know when I will have the time for it but I have a 833 tube that I won on EBay to build a really big Vacuum Tube Tesla Coil (VTTC) sometime. I cannot believe how big the 833 tube is!

2400 Volt Can Crusher

The promised and much awaited 2400 volt power supply went through its first test run. The video is up on YouTube. It was a little disappointing it takes 4 firings to get the can into the hourglass shape. One of the capacitors might be bad. Anyway a Microwave Oven Transformer charges six 400 volt capacitors through a 500 ohm 250 watt resistor. The idea is to electronically crush the soda can into an hourglass shape.

The switch to connect the capacitors to the coil is made of two 1/2 inch bolts meeting head to head. They need to be filed off after every 5 to 10 operations as they will melt together if not cleaned up. A piece of plastic holds them apart and is removed by pulling on a string.


There are 6 turns of 10 gage wire wrapped around the soda can. The last time I tried this was at 800 volts and I used about 10 turns of 14 gage wire. The wire was turned into a jumbled mess and every solder connection melted. So this time everything is connected with two 10 gage wires in parallel and fastened together with bolts. The coil has been rewound into 2 layers totaling 5 turns and is now more effective at crushing the soda can.

Below is the updated schematic. The resistors are matched with a volt ohm meter for 10:1 correspondence so that the built in volt meter will read exactly 1/10 of the output voltage. The meter runs on a 9 volt battery, I could have used the filament winding of the MOT but the 9 volt battery was easier.

There are 2 Youtube videos;

http://www.youtube.com/watch?v=lLnnI_pGP5c

Then it was improved with better results;

http://www.youtube.com/watch?v=c7JJdfe2VL4

I have been thinking about the future of can crushing. It is hard to balance this many electrolytic capacitors when they are wired up in series. Some do not completely discharge and some reverse charge. The solution would be to use higher voltage capacitors. One easy source is microwave oven capacitors but they are only 1 uF each. So now I am searching for some capacitors in the range of 10 to 100 uF at 5 to 6 KV. I hope to find something at the Ham fests this summer.

New Can crusher / Washer Launcher

I am working on what will be the biggest washer launcher or can crusher that I have ever made. If you have not seen the old washer launcher or can crusher videos on YouTube you have to see what happens when 800 volts DC is applied to a flat coil under an aluminum washer. The washer flies over 30 feet straight up. If a soda can gets in the way it can get flattened. If you place a soda can on top of the washer it ends up about 1/2 inch shorter just from the g forces.

As I was going though some of my old pictures I could see the history of my invention. First I built what was called a 'thumper' on the Internet. To make a 'thumper' essentially you take the flash from a camera and add a coil in series with the flash tube. This 'thumper' design is available on the Internet just google for a 'magnetic thumper' or 'magnetic thumpy'. Below is a picture of my version of that device.

Next I replaced the flash tube with a big SCR. I had a pile of those big SCR's that were left over from making a time machine, but they were accidentally sold at the Rochester Ham Fest in around 2005. You can see them in the background of the picture. I also started adding more capacitors. Notice the home made aluminum washer sitting on the coil. That was from before I discovered that hard drive platters make great aluminum washers. As you can tell I was already sending aluminum washers into flight. In those early days the washer flew just a few inches.

Soon I took the washer launcher to the next level. First I used 4 big capacitors and then later I stepped up to 8 of those big capacitors. I fried the old SCR and then replaced it with an ED431825 that can handle 1.8 KV (1800 Volts) and 250 amps continuous and 6.5 KA peak (6500 Amps). This design started out with one MOT (Microwave Oven Transformer) then for a while it had two MOT's.

At some point I added the flat Coil shown below. It was wound a few turns at a time then those turns were glued down and the next few turns were added. A rotating stick held the wire down while the glue was drying. The glue was of a flexible kind. At some point the wood was shattered into pieces, so it was replaced with Plexiglas. That was a bad idea. The Plexiglas shattered on the first test launch.

I am upgrading the 8 capacitor 800 volt model to now operate with up to 1600 volts. All of the capacitors had to be turned 90 degrees so that they can be connected in series instead of parallel. Here is the preliminary schematic, it is missing the 10 amp fuse, and that is a 1 meg resistor to the voltmeter that is located on the front panel.

There were two problems with the first test run of the new design. The 10 amp fuse blew because it now draws more current than that. I replaced it with a 15 amp fuse. The next problem is that the meter pegs. I was using a digital volt meter as well and it was not supposed to exceed 600 volts but it survived at 1200 volts. As far as the can crushing goes it did not crush it much more than the 800 volt model had crushed it.

Before testing it a second time I changed the resistor to the meter to 2.5 meg. The meter now reads 2.5 KV full scale. I also shortened the wire to the coil to 1/2 of the original length. The next test was at 1.6 KV and it resulted in the flattest soda can yet. The video is being
uploaded to YouTube.