Need help with 'Bob Beck'/'Chris Gupta' Magnetic Pulser

[johnri]

I am building a 'Bob Beck'/'Chris Gupta' Magnetic Pulser,
from here: http://www.newmediaexplorer.org/chris/2009/02/19/build_a_low_cost_simple_magnetic_pulser.htm



As usually happens, I am unable to source all the parts as required, I will have to make
substitutions/alterations.


I have two problem substitutions:
orig.  SCR S6020L RMS 20A, AVG 12.5A
subst. SCR TYN612M RMS 12A, AVG 8A

orig. 650 uF, 300V capacitor bank
subst. 4700 uF, 350V huge power capacitor

Now the problem is, bigger capacitor means more current but the only available SCR is of lower
current rating than the original.

I need help to solve this problem.

It has been suggested to me that I should parallel two/three SCRs, but I have never seen that
done and there is no way to ensure equal distribution of current or synchronized firing. What if
one SCR fires a few microseconds earlier taking all current load?

I haven't done any power electronics work so I don't know how to tackle this problem,
please help, any and all ideas are welcome.

[Unhappy]

Strictly as my opinion, No need to to go ahead with this schematic. why don't you try original Bob Beck schematic available?
and attached herewith

[johnri]

@Unhappy.  I am aware of Bob Beck's Blood Electrification pulser but I don't need that because I am not
trying to treat a pathogenic disease.

I am building it for treating an arthritis type condition.

[Unhappy]

@Unhappy.  I am aware of Bob Beck's Blood Electrification pulser but I don't need that because I am not
trying to treat a pathogenic disease.

I am building it for treating an arthritis type condition.

In that case you need to tell your Current(I) requirement for your electromagnetics. AFAIK circuit you posted is free running without any frequency control. You will need that also and many more things and controls to get proper results

[johnri]

The posted circuit is not intended to have any frequency control etc.,
it is simply charging up a power capacitor and discharging it through a coil on user demand.

I don't know the required current rating, all I know is, my modified circuit has a bigger
capacitor than the original circuit and this will definitely increase the current.
And to make it worse I don't have a SCR that could handle the lower amount of current
of the original circuit.

In other words, more current but weaker SCR.

I need to know if I can parallel two SCRs, if yes then how to do it.

[Unhappy]

Here we are discussing the instantaneous current AFAIK and understand.
You do not need the current to be more than few amps where TYN612 will suffice with the components available with you but using the original circuit ( not your modified circuit). I mean just replace the diodes scr and capacitor available with you in original ckt you have pasted here at first position

[LithiumOverdosE]

@johnri

Made a few pieces for friends a few years back. I was not impressed with the effects.

However search for the article "The end to all diseases" (IIRC) by Aubrey Scoon. It was published in one of the older issues of Everyday Practical Electronics. Magnetic pulses are a bit weaker but the frequencies can be quite high. BTW - with similar device I cured my ex's long standing chronic kidney infection about 12 years ago.

[johnri]

@LithiumOverdosE
Thank you for giving info. from your experience, real user feedback is always very valuable.

I (and anyone else reading this) will really benefit if you can kindly provide a little more details.

1)  You were not impressed with the results of this Magnetic thumper; what ailments did you try
to treat, this will be a useful hint to me.

2)  Aubrey Scoon's magnetic pulser helped cure kidney infection; what frequency did you use, another
bit of info. that would be useful.

I found a link to Aubrey Scoon's article if someone wants to give it a try:
http://www.electronichealing.co.uk/resources/pdf/epe_rife.pdf

[LithiumOverdosE]

I can hardly remember exact specs of the projects I worked on a year ago let alone over a decade ago.

However, IIRC a few friends tried "thumpers", "zappers" and stuff like that I made for them. IIRC They mostly tried to cure infections but other than placebo they didn't report any spectacular results.

The trick seems to be the frequency approach rather than brute force. However, realistically speaking audio frequencies usually mentioned in the alternative circles simply doesn't have any verifiable source for them. Historically speaking original Rife devices were using exclusivelly plasma radiators, they had carrier in the range of 3.5 - 5 MHz and gating frequencies in the range of tens of kHz. Even more confusion arises from the fact that two significantly different principles of operation were used in different historical devices.

In any case, audio spectrum do seem to work for pulsed magnetic fields. I treated my ex simply by choosing a few "key" frequencies around which I would wobble frequency to max 10 Hz around base frequency. IIRC I used small 0.5 Hz steps for wobble and the wobble period was as short as possible (I don't remember the specs of the function generator I used at the time. You can also sweep some audio frequency range in small steps and with short sweep periods.

I think that I treated her 3 or 4 times with treatments lasting for about 30 minutes. She got rather strong reactions, high body temperature, migraine and similar. In any case, after 7 years of fighting the infection and three hospitalisations in critical condition her lab results came negative for the first time. We split about a year or two later and during that time she did several examinations which all came negative. Definitely not a placebo IMO.


BTW - you might find this TV show a good primer on the topic of Rife and similar devices. At least I find it to be a balanced view instead of new age crap. http://youtu.be/Wc44kzFHgrQ

[zab]

I don't know the required current rating, all I know is, my modified circuit has a bigger
capacitor than the original circuit and this will definitely increase the current.
And to make it worse I don't have a SCR that could handle the lower amount of current
of the original circuit.

In other words, more current but weaker SCR.

I need to know if I can parallel two SCRs, if yes then how to do it.

Yes you can use 2 or more SCR in parallel. for that you have to use same type of SCR. I had once used triac in parallel as well. For using them in this configuration just connect anode to anode and cathode with cathode.for gate you joint them or use separate resistor for them.

Big capacitor with out series resistor will have huge inrush current. that may damage rectifier diode. So when you have big capacitor on filter you some sort of soft start (controlled charging )or a series resistor at least .

[Unhappy]

Yes you can use 2 or more SCR in parallel. for that you have to use same type of SCR. I had once used triac in parallel as well. For using them in this configuration just connect anode to anode and cathode with cathode.for gate you joint them or use separate resistor for them.

Big capacitor with out series resistor will have huge inrush current. that may damage rectifier diode. So when you have big capacitor on filter you some sort of soft start (controlled charging )or a series resistor at least .

You may use series ballast resistor (of lowest ohmic value/high wattage) available with you for paralleling the SCRs TYN612.
Each SCR Cathode in series to ballast resistor. Already used many times by me effectively

[johnri]

Yes you can use 2 or more SCR in parallel. for that you have to use same type of SCR. I had once used triac in parallel as well. For using them in this configuration just connect anode to anode and cathode with cathode.for gate you joint them or use separate resistor for them.

Big capacitor with out series resistor will have huge inrush current. that may damage rectifier diode. So when you have big capacitor on filter you some sort of soft start (controlled charging )or a series resistor at least .

I am using a 25VA 125V isolation transformer for the source, do I still need to worry about the inrush current
since the power source is unable to provide any heavy current (max. 0.2A).

[Unhappy]

@johri
Charging current(peak Imax @4mSec) is calculated by CRtime your supply may withstand if it is perfectly rated as per Standards

[johnri]

@johri
Charging current(peak Imax @4mSec) is calculated by CRtime your supply may withstand if it is perfectly rated as per Standards

I am sorry but all this is Greek to me.

I asked a simple question, I am sure it can be answered simply as well.

I am using a 25VA 125V isolation transformer for the source, do I still need to worry about the inrush current
since the power source is unable to provide any heavy current (max. 0.2A).

[Unhappy]

I am sorry but all this is Greek to me.

I asked a simple question, I am sure it can be answered simply as well.

I am using a 25VA 125V isolation transformer for the source, do I still need to worry about the inrush current
since the power source is unable to provide any heavy current (max. 0.2A).

OK, for a layman and noob point of view nothing to worry about and even more,only one SCR will do although you may not get the optimum performance

[Ichan]

Can't comment on paralleling SCR, would like to hear your experience. On the schematic provided I am not worried about the charging, it will just take sometime to charge the caps up - but i am worried with discharging that 4700uF 350V capacitor, it can make a loud bang.

100A IGBT perhaps?

-ichan

[Unhappy]

@Ichan
Thanks for pointing that out, definitely not for layman/noob to build this circuit. I am sorry again for not viewing that 

[johnri]

@Unhappy
I am not a noob, sorry, my use of simple terms must have given that impression.

@Ichan
Hehe, you have a sharp eye. This huge capacitor can/does create a LOUD bang. I don't need to to
buy any fireworks, lower rated SCRs, connecting wires work just as well.



Although I was asking about paralleling 2 SCRs, I was planning on using 5, even then I wasn't comfortable
with it.  

I have got a lead to a local source for a 600A peak rated SCR, that should solve the problem.