My Home-Made Bob Beck Electromagnetic Pulser (Thumper)
If you made it to this web page, you most likely have already been researching the Bob Beck Protocol. If you have no knowledge of electronics and are wanting to build your own pulser, I recommend thoroughly going over Chris Gupta's Pulser page first and then coming back here to fill in the blanks. Here I offer photographs and additional information that may be of assistance to anyone wanting to build their own Bob Beck Electromagnetic Pulser.
Bob Beck Protocol Information: If you would like to learn more about Robert Beck and the Beck Protocol, you can view several Google Videos by clicking on the following Link - Beck Video. Beyond these videos, there is a wealth of information on the internet about the Bob Beck Protocol. In a nutshell however it implies a four process system involving blood electrification, electromagnetic pulse, colloidal silver and ozonated water. If you are experiencing cancer, hiv, lupus, candida or one or more of a host of other ailments, it would be worth your time to research this health process. Also, you can download the entire Bob Beck Lecture, "Take Back Your Power" (1MB PDF). I have searched hi and low for this and finally found the complete document.
Commercially Manufactured Bob Beck Devices: If you are looking for a quality blood electrifier at a fantastic price of only $70, click on the following link (http://photoman.bizland.com/godzilla/details.htm). It uses four 9V batteries. Other commercial models may use only a single 9V battery but can cost up to $200. If you don't want to, or can't build your own blood electrifier, this device should suffice nicely. I will soon have a web page outlining instructions with photos, to assist those who want to make their own blood electrifier. In the meantime, you can access the following web site for a schematic and parts list of Bob Beck's original, improved Blood Electrifier and Colloidal Silver Maker
Sota Instruments manufactures
and sells more advanced devices ranging from
EM Pulsers to Ozonating devices and more.
Also see Tools For Healing.
Some more technical information provided by Sota Instruments regarding the construction of electromagnetic pulsers can be found by clicking on this link.
My EM Pulser is based on Chris Gupta's circuit design. Chris Gupta's Pulser web site can be accessed by clicking on this link.
The information I provide on this web page is an account of what I have learned in the process of studying Beck devices and building my own units for my own experimentation purposes. I assume no responsibility for anything one might do with the information provided on this web page. Please view any explanations as hypothetical and not as instructions to be followed.
Electric Shock Hazard!
This device uses 110V AC current and a bank of capacitors that stores a significant charge. If this device is not built in a safe manor, there can be a risk of lethal electric shock. It would advisable for individuals that are unfamiliar with electronics, to have someone like a TV repairman build this device for them. PLEASE PLEASE PLEASE be absolutely present, mindful and cautious when working around exposed capacitors and 110VAC current. As you will read below, even a shock by a single capacitor from a disposable camera, can be extremely unpleasant. A professor at Penn Engineering jokingly recommended that I keep one hand in my pocket. In other words, keeping one hand in my pocket would prevent an electric shock from going across my heart!
Looking on the bright side however, Chris Gupta told me that many people have successfully built and are using this device based on his schematic. I'm just asking those that are intending to build this machine, to use safe practices when working around exposed capacitors and hot electrical wires.
Please post any successes, failures, comments or questions on Chris Gupta's Pulser web page.
Please take a close look at the photos below before reading on. As I don't provide a lead-in, reviewing the images will help you to understand what I'm talking about.
All measurements are in Inches.
Plastic Box Outside Dimensions:
approximately 2-3/8 X 4-1/4 X 7-3/8
Using 1/2 inch #4 beveled machine screws I fastened a 1/8 inch plexiglas sub-floor to the bottom of the box in order to allow for the attachment of the Terminal Contact Bars and the home-made bracket for the SCR. The sub-floor also provides an insulated suface for the circuit components to be mounted to. Screws were counter sunk into the outside-bottom of the plastic box and fastened on the inside with a lock washers and nuts. After all components were soldered and attached to the sub-floor, the sub-floor was then fastened to the ends of the four screws coming up from the bottom of the box and again fastened with nuts and lock washers.
Looking at Chris Gupta's EM Pulser circuit, keep in mind that the On/Off switch is on the positive side of the circuit. The negative side goes to the bulbs, 150V / 130uF capacitor and ultimately to the Anode of the SCR. In electrical circuits, generally it is always the hot lead (+) that is switched. I'm not really sure if input polarity makes a difference in this circuit, but that is how I did it.
Note: I have since modified my pulser by adding three contact bars to strengthen, simplify and clean-up the solder points for the 150V / 130uF capacitor, two diodes and the resistor. I also added two more photo-flash capacitors to the five shown in the diagram. According to Chris Gupta's calculations the array of 7 capacitors now store about 41 joules (Watt/Seconds) of energy and will produce a magnetic pulse of around ~6,000 gauss from the surface of the coil.
I used 14 gage solid copper wire to and from the photo flash capacitor buss to add strength and stability to the circuit components.
Implementing a Strain Relief:
Strain reliefs are essential for electrical safety. They prevent cables from being ripped out of a circuit in the event an electrical device gets dropped or e.g., should someone trip over an electrical chord. I did not have a strain relief when I assembled my pulser. I plan on adding two strain reliefs, one for each chord coming out of my device.
Ground Fault Circuit Interrupter (GFCI):
AGFCI is designed to instantly interrupt the flow of electricity in the event of a short circuit, before it can become a danger. A short circuit is basically when electricity finds an alternate path to ground, instead of going through the intended circuit. A short circuit can happen within an electrical device, or it can happen through a person who has unknowingly provided a shorter electrical path to ground. I recommend using a GFCI in conjunction with this device. Probably the easiest way to do this is to purchase an extension chord or a power strip that has a GFCI as part of the unit. Modern building codes in the United States require all kitchens, bathrooms and out-door circuits to have GFCI circuit breakers or receptacles.
The SCR (Silicon Controlled Rectifier) and has three contacts. In my device the SCR is mounted onto a home-made bracket to again add more stability to the circuit components. The bracket for the SCR and all other components of this device are mounted to an insulative plexiglas sub-floor using 1/2 inch #4 standard machine screws .
1.) Anode: The entire casing of the SCR, including the treaded portion and the threaded nut (when attached), is the Anode and is HOT when the unit is fired up. The SCR I used had an insulator to insulate the Anode from a mounting bracket. Included with the threaded nut and insulator, was also a metal ring which serves as the Anode solder point. See diagram and photo below.
2.) Gate: In Chris Gupta's circuit, the Gate of the SCR connects to one side of the Push-To-Make switch. On the SCR that I used, the Gate was the shorter of the two solder points coming up from the top of the unit.
3.) Cathode: Again, on the SCR that I used, the Cathode was the longer and thicker of the two solder points coming up from the top of the unit. It connects to one lead of the coil.
Note: The other lead from the coil is soldered to the negative buss of the photo flash capacitor array. See schematic and Photos.
I used a 3/4 inch EMT (electrical conduit) mounting bracket to fabricate a U shaped bracket to mount the (Philips ECG 5529) SCR to. First I pounded the bracket flat, and then bent and cut it to the desired shape. The bracket was mounted to the sub-floor using one 3/8 inch #4 phillips machine screw, lock washer and nut. I had to shorten the length of the machine screw in order maximize the distance between the end of the screw and the bottom of the SCR. The bracket had to be short enough to provide enough clearance for the box cover, but long enough to provide sufficient clear space for the bottom end of the SCR. See photo below. The SCR attaches to the bracket between the two insulators. When the assembly is tightened, the insulator provides effective insulation for a metal bracket.
I should perhaps mention that I drilled a hole into the top surface of the bracket that was large enough for the protrusion of the upper insulator to fit through. The lower insulating ring comes up underneath the bracket and is held in place by the Anode solder point ring and finally the nut. See SCR diagram above.
I wired the ground wire to the housing of the Push-to Make switch as this is the only metal component I touch during the operation of the Pulser. I decided to use a plastic box over a metal one, because there is so much current flying around and I wanted reduce the chance of any short circuits. I also made sure that all of the components were all sufficiently spaced apart from each other. Since there is a fair amount of current flying around this machine, Chris Gupta recommended not to use a printed circuit board to build this device. That is also why I opted to implement the use of an insulated plexiglas sub-floor to mount all of the components to.
SCR Update January 2015: I am switching to a new surface mount SCR that is more robust than the Philips ECG 5529 post mount SCR I have been using.
The new SCR is the LittleFuse S4065JTP Thyristor. It is more in line with Gutpta's original specifications listed on his schematic. The S602L that Gupta lists on his schematic is actually not in compliance with his own specifications for that component, as it only has a "Peak Amp" rating of 255A. The LittleFuse S4065JTP Thyristor/ SCR has a 40A continuous and an 800A peak amperage rating, which does meet Gupta's design specs.
Specifications are as follows:
• Current It av: 41A
• Gate Trigger Current Max, Igt: 50mA
• Gate Trigger Voltage Max Vgt: 2V
• Holding Current Max Ih: 80mA
• MSL: -
• No. of Pins: 3
• On State RMS Current IT(rms): 65A
• Operating Temperature Max: 125°C
• Operating Temperature Min: -40°C
• Peak Non Rep Surge Current Itsm 50Hz: 800A
• Peak Repetitive Off-State Voltage, Vdrm: 400V
• SVHC: No SVHC (16-Jun-2014)
• Thyristor Case: TO-218X
• Thyristor Case Style: TO-218X
This SCR needs to be mounted on a heat sink to prevent the component from overheating. Both items can be purchased from Newark element 14. Newark part numbers are as follows.
LittleFuse S4065JTP Thyristor/SCR - Newark Stock Number #99K0083 - Web Page
AAVID Thermalloy 6396BG Heat Sink - Newark Stock Number #6396BG - Web Page
Bulbs and Lamp Holders : I used candelabra lamp holders as they take up less space and are less bulky. Holes of the appropriate size were drilled into the top of the box about 1 inch in from the edges. The main thing here, is to make sure that the bulbs are not touching when screwed into the sockets. My pulser makes use of two spherical shaped 60W bulbs. The spherical bulbs were more aesthetically pleasing to me than traditional candelabra bulbs. Should a bulb burn out, replace it before continued use. In Chris Gupta's design the bulbs act as current limiters and protect the SCR from short-circuiting.
Note: Keep in mind that the bulbs do get hot if you are using the pulser for several minutes at a time.
Inductor Coil: If you want to go the easy way like me, and don't want to go through the hassle of building your own coil, two options can purchased from Madisound Speaker Components, Inc. This link will take you to the correct page on their web site. You are wanting the Sidewinder 2.5 mH 16AWG Air Core Inductor Coil ($20.60). One can also use the Solen 2.5 mH Perfect Lay Inductors 14 AWG ($32).
Note 1: The AMS coil that is listed in numerous Beck texts
as an alternative to building your own, is no longer manufactured.
Connecting the Inductor Coil and the Switch: The inductor coil attaches to the Cathode of the SCR and to the negative 'Contact Bar' of the capacitor bank. The push-to-make switch attaches to the gate of the SCR and to one of the following: directly to the + buss or contact bar of the capacitor bank, between the positive buss buss of the capacitor bank and the anode of the SCR (See Photos), or directly to the anode of the SCR. However you hook up the switch, keep in mind there is a 10K resistor between the switch and Anode of the SCR.
Photo Flash Capacitors: The ability of a capacitor to store a charge is measured in 'Farads'. Most capacitors are labeled in Micro Farads (uF). The photo-flash capacitors you see in the tray below, all came from one run to a local drug store that does photo processing. They are all from an assortment of disposable flash cameras and range from 80uF - 160uF.
On this occasion I hit the jackpot as the camera recycle bin was full. I could have selected twice as many. Different camera manufactures and even cameras from the same company will often have caps of different ratings, ranging anywhere from 330V 80uF - 330V 160uF, and on occasion even higher. Larger capacitors with higher voltage and uF ratings can store more energy. When hooked up in parallel the uF ratings are cumulative. Two capacitors rated at 330V 80uF hooked up in parallel, will have a combined rating of 330V 160uF. When hooked up in series, it is the voltage rating that increases. The same two capacitors hooked up in series would have a combined rating of 660V 80uF. Note how the capacitance is NOT additive when hooking capacitors up in series. For more information on hooking capacitors up in series click on this link.
Chris Gupta offers the following general rule of thumb about capacitors hooked together in a parallel configuration: The voltage flowing through a set of capacitors in parallel, should not exceed the voltage of the lowest rated capacitor. For example if you connect a 330V 80uF capacitor and a 150V 80uF capacitor together in parallel, the combined voltage rating of the two will be 150V.
Capacitor Ratings From Various Cameras I Have
Kodak Power Flash: 120uF & 160uF (two slightly different models)
Kodak Zoom: 100uF & 120uF
Kodak FunSaver: 120uF
Polaroid Fun Shooter: 80uF
Studio 35: 80uF
In regard to capacitor (bank) C2, it will be difficult to find130uF capacitors from disposable cameras. The highest rated capacitor I have been able to find from a disposable camera is 160uF and out of over 100 cameras I have taken apart, I have found only one with such a rating. Most photo-flash caps you will get out of a camera are between 80uF and 120uF. Keep in mind however, one can mix and match capacitors in parallel to arrive at the desired microfarad rating. I have switched to using a single 1000MFD 330V Rubicon Photo-Flash capacitor for C2. Also in compliance with Russ Torladge's (Sota Instrment) suggestion I also add a high voltage silicon rectifier across the terminals of the capacitor. The reason for this is explained in more detail below.
Click here for more information on capacitor charge calculations.
Observing Chris Gupta's circuit design, you see that his schematic calls for one 150V 130uF capacitor just past the two bulbs. All of the caps I have removed from disposable cameras are all rated at 330V. According to Chris Gupta, it is OK to use a 330V capacitor in this location. Hypothetically, if one were using 330V 80uF caps to build a pulser, one might consider using two 80uF caps hooked together in parallel to bring the combined uF rating up to 160uF. Likewise for the capacitor array; if all one had was 80uF caps to build a pulser with, one might want to add capacitors to the array in order to reach the 650 combined uF (micro farads) called for in Chris Gupta's design. In this case one might consider using 8 - 9, 80uF capacitors in the pulser construction, providing a combined rating of 640uF and 720uF respectively.
To be consistent in my pulser design, I used all identical caps from Fuji cameras for the 5 (and now 7) capacitors in my array (see images below). There are two basic designs in Fuji disposable cameras. One uses a larger cap than the other. Because the caps in Fuji cameras are not labeled, I had no way to tell for sure, what the combined uF rating is for the capacitor array in my pulser. I came across a source on the internet, that gave me a clue that the capacitors in my pulser may have a rating of 160uF, as the capacitors Fuji uses, seem to be either 100uF or 160uF. Since I used the larger of the two capacitors in my design, I can assume that the caps in my pulser are 330V 160uF. If this is the case then the capacitor array in my pulser has a combined rating of 330V 1120uF (160uF X 7 = 1120uF).
The negative terminal of electrolytic capacitors is marked by a stripe running down the side. Two 5-contact, Terminal Contact Bars were used to solder the photo flash capacitors to. As the capacitors need to be connected in parallel, each Terminal Contact Bar has a piece of 14 gage copper wire soldered at each contact across the span of the bar to unify all contacts. The Negative pole of each capacitor is soldered to one contact of the terminal contact bar and the same for the positive side of the capacitors. Be sure the screw mounts are facing toward the outside. Once the capacitors were soldered in place, I marked the hole locations on the plexiglas sub-floor and drilled the holes. The assembly was then fastened to the sub floor with 1/2 inch #4 phillips machine screws, lock washers and nuts. See images below.
Most often capacitors in spent disposable cameras will still have a charge and can shock you if touched. If you attempt to build your own pulser, please be sure to always discharge capacitors before removing them from a camera.
SHOCK HAZARD: If you disassemble a camera, be extremely careful when removing the cover and handling components. Avoid touching any of the circuitry until the capacitor has been discharged. I recently got shocked from a camera that had a 330V 80uF capacitor inside, and it really hurt! The jolt went up my whole right arm and it took about a half an hour for my hand and arm to feel normal again. Capacitors are not to be taken lightly and should be considered dangerous and potentially life-threatening!
During testing, when I discharged the capacitor array, it sounded like a firecracker going off in my ear and the tips of the 14 gage wire were slightly melted. There was a noticeable difference in the discharge strength of seven capacitors as compared to five. One does not want to get shocked by that! A jolt like that going across one's heart could be lethal! - Please be careful and always discharge capacitors, even if you think they are not charged. Instructions to build a capacitor discharge tool that will safely discharge a bank of capacitors is outlined above.
Making a Capacitor Discharge Tool: One can make a capacitor discharge tool with two insulated alligator clips, about 16 inches of 14 gage stranded wire and a 10,000 ohm, wire-wound, 10 Watt resistor. Solder an insulated alligator clip to either end of the insulated wire. Then cut the wire about 7 inches from one end, and solder the resistor in place. Now wrap the resistor and solder points with at least three layers of ELECTRICAL TAPE.
Discharging Capacitors: Carefully connect the alligator clips to the capacitor terminals (one clip to each exposed terminal). The resistor will drop the voltage down in a minute or so.
Since I first made this device, nearly ten years ago, I have also made changes to my EMP circuit, in that I no longer use a capacitor bank of 5 scavenged photo-flash capacitors from used disposable cameras. I now use a single 330V 1000MFD photo-flash capacitor instead, that I was able to purchase from ebay for about $5. You will find more information about this below.
Diodes are also directional and must be installed properly. Their primary function is to insure the flow of current is only in one direction. This symbol is used to indicate a diode in a circuit diagram. Current flows from the cathode side to the anode side. If they are installed with the polarity reversed, your pulser will not work. The stripe on any diode indicates the cathode side and the negative pole.
About flying fender washers: My washers don't fly up from the center of the coil as with some other designs. Washers on my unit fly in line with the sides of the coil. When experimenting with this, one needs to play around with the magnetic field until one finds the right spot. Once I figured out the correct positioning for the washer, I was able to get a 1-1/2 inch fender washer to soar about 40 inches into the air. Pretty amazing!
Starting my Pulser for the First Time: I didn't know what to expect when I plugged the chord into the outlet and pressed the on switch for the first time. The lights came on momentarily and then went out. Chris Gupta told me this was normal.
Should you build your own machine based on this design, and after turning the unit on, the lights come on and stay on, immediately turn the machine off and troubleshoot your assembly! Also if the lights don't come on at all, then something is amiss as well. I had rubber gloves on when I pressed the push-to-make switch for the first time. When pressing the push-to-make switch the lights shown brightly and I could hear a slight momentary sound from the wires in the coil. Again, Chris said this was normal. All was well and I had successfully built my pulser. After repeated pulses, the coil will begin to get warm. This too is normal.
Note: Always press and instantly release the push-to-make switch. The circuit is designed for repeated but momentary bursts of electromagnetic pulses. Keeping the push-to-make switch depressed will damage your pulser.
Chris Gupta's Instructions and parts List:
Well finally, I have got all the wrinkles out my prototype SCR Thumpy. And this circuit has definitely got the power. You can actually feel an electric current pulse when used in the neck area - uncanny! This is subtle however. I hasten to add that power is not the be all and end all, indeed, it is quite possible to design very effective low power pulsers with exceptionally fast pulse rise times that can surpass the performance of even the most powerful pulser. Unlike the high power pulsers these minimize dangers from electromagnetic radiation. So be warned and don't get carried away with the lure of high power! It has been long known amongst alternate energy and electromedicine researchers that very high speed pulses have the ability to tap into some form of radiant energy that is generally not recognized by mainstream science. Devices with very weak but high speed pulses in nanosecond range have been build and efficaciously used by NASA engineers. This is a well known phenomena and I have worked it out mathematically to my satisfaction. More on this at a later date. One theory is that such weak high speed pulses are able to by pass the cell electromagnetic defences by their sheer speed but certainly there are other issues a play such as tapping radiant energy... For a better description on this please see Dr. Glen Gordon's video here. Dr. Gordon was a candidate for a heart transplant but managed to rebuild his own heart by just such a device.
See also: BIOELECTROMAGNETIC MEDICINE - THE BOOK
Please note that this is not a permanent magnet but a pulsed magnet and as such the polarity is not an issue, when the pulse collapses the magnetic field reverses. Hence one need not worry about the magnetic polarity.
I still don't like the auto types as the body gets habituated to non random pulses the only exceptions are possilbly the natural beat frequency of the Earth magnetic field (9.6 Hz) AND the Schumann waves (7.83 Hz) - a random pulser circuit is still the goal but due to great demand, much against my will, have now included a constant pulsing option for those who requested it. For the sake of simplicity a neon lamp is used. Unfortunately neons are not very stable and tend to vary as time goes by and may need to be replaced so use a socket for a quick change. The pulsing rate can be changed and should be changed every so often so the body does not get habituated, to that end I have added a switch to change the pulse rates...
To calculate the output energy use the following:
W=energy in joules: C = Capacitance in farads: E = Voltage across Capacitor in volts
# capacitors #Joules
More on Capacitor Charge Calculatio re.
Any SCR with PEAK current of at least 600 to 1000 amps should work. The one shown is 20 amp continuous with the appropriate peak rating. The lamps act as current limiters and protect the SCR against a short circuit. The circuit can be further simplified as discussed in point 3 below.
I have build several of these and my experience has been:
1) The capacitors develop a memory and don't fully discharge its better to use a number of them in parallel. This reduces the internal resistance and provides a better result and less memory loss. The caps must be designed for flash applications. They need not all be the same value but must be the minimum voltage rating stated.
2) In the original Beck based designs the flash tube heats and develops some resistance so you need to have enough time between flashes for them to cool down. This has been eliminated in my circuit, however, you still need some time for the capacitors to charge up. The larger the capacitor bank the longer it will take to charge up. Those planning to incorporate the automatic version must be mindful of this and adjust the timer circuit to compensate this effect.
3) Using a high current SCR (forces the caps to fully discharge by providing a longer connection than the strobe) and parallel caps from disposable cameras I can now consistently get 12 - 18 inch jumps with #14 fender washers. You can cycle them very fast (though not recommended). All for less than $30 to $50 Cdn. The most expensive part is the coil which can cost as much a $20 unless you build it yourself! One can further reduce the cost if at a latter date you don't want to upgrade to auto pulsing. This can be accomplished by removing the 10k resistor and the SCR and by simply wiring the a push to close switch in line to the coil. Don't recommend this unless you just can't get an SCR or really need to reduce cost. MAKE SURE THE PUSH BUTTON SWITCH CAN HANDLE THE CURRENT AND IS MECHANICALLY ROBUST!
More info regarding other coils options etc. is available at:
Coil winding instructions from Dr. Beck's paper are:
"Junk VHS videocassette reels are cheap, plentiful and adequate for this application. Remove 5 screws from shell, remove reels and discard tape. Be SURE alternative spools (if used) are non-conductive or system will not work. Avoid shorter length VHS tape reels which may have center hubs larger than 1" dia. and won't hold sufficient wire. Drill 1/4" holes through hub and through center of flange(s). Make two 4" discs from 1/4" thick plastic or fiberboard, drill 1/4" center holes and another 1/4" hole off-center so coil's inside lead wire can be pulled through. These 'stiffeners' will sandwich reel's flanges so they won't warp or split as wire pressure builds up while winding progresses. A 2" (or longer) 1/4-20 machine nut and bolt with washers through centers will clamp flange stiffeners and reel and also provide a shaft to hold in a variable speed drill motor or similar winding device if used. Then remove bolt and stiffeners.
Specifications: Completely fill tape spool with #14 or 16 enameled copper magnet wire (130 to 160 turns) wound onto the 1" dia. hub and 3-1/2" OD spool with a gap width for wire of 5/8". Scrape enamel insulation 1/2" from ends and tin. Pull inside end of magnet wire through hub and stiffener and to outside. ~130 turns (about About 1-1/2 lbs should fill spool. Remove bolt, stiffeners, and finished coil. Now solder ends of 3 ft of heavy two-wire extension cord to each side of coil. Finished coil weighs ~1 LB 3 oz, has ~0.935 millihenry inductance, 0.34 ohm resistance, and takes ~20 minutes to hand wind or ~3 minutes with drill motor. An excellent alternative is an AMS brand air-core crossover inductor for home audio, #16 gauge, 2.5mH, 2-1/2" dia., $17.90 from Madisound speaker components.
Chris Gupta's EM Pulser Circuit
Those interested in using a 12 V DC source use a cheap 75 watt car inverter I bought one on sale for just $7 Cdn! Simply remove one of the bulbs. This of course is easier if at least one bulb is in a socket.
I recently switched to using a single Rubicon 330V 1000MFD photo flash capacitor. I purchased it for $5 on E-Bay. I also followed Russ Torlage's recommendation and installed a MR756 silicone rectifier diode across the capacitor's terminals in order to prevent current from traveling back across the capacitor an damaging or destroying it. Below is what Russ Torladge, owner of Sota Insgtruments has to say about it.
"When the capacitor gets fully charged, we must dump this high energy into the coil somehow. Originally a Xenon photoflash tube was used as a thyratron switch (the Xenon gas is ignited to a plasma which provides a low impedance path for the electron flow) for the do-it-yourself'ers. The Xenon tube presents about 1-3 ohms of resistance when ionized. It makes a good switch, but it does restrict peak current flow. Ringing can and does occur with the capacitor-coil combination because the current can back-feed into the capacitor. (This ringing affect can allow reverse-biasing of the main capacitor; degrading it's life-span very quickly or destroying the capacitor under extreme conditions.) When a capacitor is in series with an inductor in this manner, it is known as an L-C (Inductive from the coil and Capacitive from the capacitor) circuit.
Xenon tubes get hot, and they waste energy in the form of heat and (of course) light. A better switch is an SCR (Silicon Controlled Rectifier) of appropriate voltage and current rating (800-1000 Volts @ 25 Amps is a good start.). An SCR provides a one-way path of current flow from capacitor to coil, inherently preventing ringing and therefore saving the capacitor from reverse-biasing. This one-way path ensures the output magnetic field is DC based or uni-polar. This means North magnetic pole will always be on one side of the coil, and will not change to South pole at any time.
NOTE: Although a typical SCR is a fast operating device, there will always be a "dead-time" where the device is in a conductive state (known as tq which is typically = 35uS). This can allow reverse voltages to appear across the main capacitor which may eventually lead to a much shortened lifetime or the complete destruction of the capacitor. So, in order to prevent such an event we need to suppress this high-power content reverse voltage spike across the main capacitor. The simplest, effective and most economical way is to place a high-current diode in reverse, across the leads of the main capacitor. The CATHODE (-) lead of the diode connects to the POSITIVE (+) terminal of the capacitor. Remember, this reverse-voltage spike can contain many joules so you must use an adequately rated diode. We use an MR756 silicon rectifier. It is rated at 600 Volts DC, 6 Amps continuous and 400 Amps peak surge. I measured over 80 Amps of current in the reverse-voltage spike. WARNING: If you do not use a similar rated diode, it may very well blow up in your face! I know, because I had this happen many times while taking measurements. Scares the heck out of you!"
December 10th 2013
December 10th 2013
Some more technical information provided by Sota Instruments regarding the construction of electromagnetic pulsers can be found by clicking on this link.
Please post any successes, failures, comments
or questions on Chris
Gupta's Pulser web page.
Some individuals have posted claims that Chris' design is flawed. I for one, can attest that his design is sound and works well. If after constructing your device it fails to work, it is most certainly an error in construction. If your device does not work, the capacitor polarity may be incorrect, one or more diodes may have incorrect polarity, a component may be burned out or defective, or there is an error somewhere in how things were assembled and soldered. Watch for any arching on your component board.
I sell these devices for experimental purposes for $279.
Feel free to contact me for more information