Understanding electricity in the TPU.

[NickZ]

  Guys: 
   I was just watching IST's last videos and I do belive that he may have hit on something.
  That is:   That it is Not the Coil Design of a TPU that is of main importance, as almost any wire coil can be shown to work, although coil-tuning useing different coil types does improve the effect.  BUT, that the SECRET lies in the way the coil is wired so that the Output is being FED-BACK into the Input, and thus making the device run with gain. 
   He has shown the effect by first using a 12 volt battery,
to charge a big capacitor, and pulse a coil,   then with no car battery, just a big charge holding capacitor, previously charged, to a pulse coil, that will start and maintain itself running, and finally shows how with even no capacitor the coil (by itself) will self run once started, and charge a battery at the same time. 
  Is this too good to be true?   His proof of concept videos are out and can be seen by all.
                                      NZ

                                                                 
                                                                       

[forest]

  Guys: 
   I was just watching IST's last videos and I do belive that he may have hit on something.
  That is:   That it is Not the Coil Design of a TPU that is of main importance, as almost any wire coil can be shown to work, although coil-tuning useing different coil types does improve the effect.  BUT, that the SECRET lies in the way the coil is wired so that the Output is being FED-BACK into the Input, and thus making the device run with gain. 
   He has shown the effect by first using a 12 volt battery,
to charge a big capacitor, and pulse a coil,   then with no car battery, just a big charge holding capacitor, previously charged, to a pulse coil, that will start and maintain itself running, and finally shows how with even no capacitor the coil (by itself) will self run once started, and charge a battery at the same time. 
  Is this too good to be true?   His proof of concept videos are out and can be seen by all.
                                      NZ

                                                                 
                                                                     

Can you post link to that video ?

[gyulasun]

Something is screwy in Camelot.

I can't redo what I showed in the last video.

I made a small change in how the mosfets are held but no changes to the circuit diagram. Everything is the same, everything, and now no more effect at 800 volts. Shit. I'm getting the 340 volts I had in the first video.

I have been trying to redo it all weekend. I looked back at the video so many times but just can't figure it out.

Why did I do the change? Because I noticed on the terminal block that I used to hold the mosfets together required that I bend the mosfet terminals so much but even then the gate of the npn was not solidly held by the terminal block screw because the copper lead (with the red tape) was there also. So that mosfet gate terminal was a little loose during the demo even though it worked. Seeing this looseness, I decided to fix it and now the effect is gone. Vanished. WTF, is it possible that with the mosfet gate terminal loose this caused at 300 volts level enough miniature sparking that it jumped up to 800 volts.

The answer to the following question would help me realize what went wrong.

So, during the changeover, I also changed the mosfets, same models, but new mosfets. So I am wondering about mosfets. During their useful life, can they gradually change or degrade in their output specs, or, do they work like they work until they just blow.

Anyways, like I said, something is screwy in Camelot.

wattsup

Hi Wattsup,

My guess is also the loose gate connection earlier gave the high voltage as a present for you becaue it may have introduced extra speed switching time you would not normally get with even such excellent FG pulse rise and fall times your HP has.  (induced voltage V_i=L*dI/dt where L is the coil inductance, I is the change in current and t is the time during which the current change happens, so the smaller the time is the higher the induced voltage you get)

Regarding the possible change of parameters in MOSFETs, if the absolute voltage and current ratings are not exceeded, they normally do not change.

(Recall what I wrote earlier on the max peak current when you can judge the max current by Ohm's law as the supply voltage divided by the coil's DC resistance, this is why it is better to start with 3-5V DC supply voltage instead of the 12V or higher, especially if your coil has a thick wire (obviously to reduce copper loss). Just as an example if your coil has only a  .3 Ohm resistance and your power supply has about .1 Ohm inner resistance and your MOSFET also has 0.1 Ohm ON resistance each (N and P channels in series), then the peak current can be at 12V supply voltage 12/(.3+.1+.1+.1)=12/.6=20A! what can only be less because of the duty cycle less than 50% etc but what I stress is you can easily approach the limits for max drain current of the different types of MOSFETs. And once you exceeded it, the MOSFET may get a damage inside.

Another data to observe is the max drain-source voltage: you have had over 800V DC collected in the capacitor, this means at least as high peak AC spike across the drain-source what the MOSFET must resist. I think you surely exceeded the 500V maximum limit the IRF840 is able to handle, though here we have to consider the series n channel IRF9540 has about 100V max V_DSS rating! added to the 500V, so you still exceeded the max voltages for BOTH!  So it was a wonder your devices handled the 700-800V peaks at all....

However you changed the old FETs to new ones, now you get about 340V,  so what remains as possible explanation for the over 800V induced voltage is the loose gate contact...    (by the way, earlier I did not realize the IRF9540 has only a 100V max drain-source voltage rating, otherwise I have already warned you about it).

rgds,  Gyula

[giantkiller]

Ditto...

Can you post link to that video ?

[wattsup]

@gyulasun

OK, thanks for the explain as usual.

I decided I am not going to spend any more days trying to hunt this effect again and will live with the present output available and work from there, otherwise I risk spending more time for nothing. I just wanted to report the problem right away so guys do not think this or that.

I have another question since my questions help me to advance to next steps. If you have one pulse generator source and two npn mosfets with their drain and source in parallel, is there a way to pulse one gate directly from the PG and then the other gate is also pulsed from the same PG but at a lower pulse rate using a capacitor/potentiometer setup.

I know you are not that familiar with the SM TPUs but in his biggest unit, he is only using one pot and we are certain he is using at least two frequencies in his coils.

@GK

Nice coil you made on your thread. You may try to add a center tap to the outer coil.

You know when we start looking at effects then get drawn into one direction for some time, often forgetting about the previous effects or even more the previous second and third trials, some time ago I was doing specific pulsing with the center ring just biased to north polarity (since in the northern hemisphere we are all swimming in the south polarity), that is when I blew my HP 214B pulse generator. My beautiful beast is no more.

I am heading back into that direction for a little while just to get that effect again and master it so I can teach others about it. I am sure it has something to do with the TPU otherwise the STPU and onwards could not have done this via straight mutual induction. There has to be a common method to work a purely biased loop. I think I know how now but will test and report back.