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Building lt spice transformer / help!

Discussion in 'General Electronics Chat' started by killivolt, Oct 6, 2013.

  1. killivolt

    killivolt Well-Known Member

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    I was thinking the same thing, but didn't want to say it. However, I can't explain the work being done with M1 and M2? 206 Amps should blow them up. I'm not sure what's happening?
     
    Last edited: Oct 11, 2013
  2. ronsimpson

    ronsimpson Well-Known Member Most Helpful Member

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    with R and C the osc should work. It does not. With out a ramp on 'C' nothing will work.
     
  3. ronsimpson

    ronsimpson Well-Known Member Most Helpful Member

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    It is dead. I can see some ringing in the transformer at power up. I lowered the Q of the transformer and the power up ringing stopped.
    Maybe some one can remind me how to edit a sub circuit and we can see how the 3525 was built.
     
  4. dave

    Dave New Member

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  5. killivolt

    killivolt Well-Known Member

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    I got hungry again, which is a good thing, I came back to see your post's.

    Apart from that, I think maybe I should just put this on a Development board and watch it burn! Haha, well I'm just saying how will I know otherwise without the 3525 being corrected.

    So, you are saying your getting the Mosfets working? If so, I want to let them burn. It will tell me that the circuit can work but, much is not explained and the author is going to use that knowledge for what ever reason. But, it will cost you sum $ to know.

    kv

    Edit: I'm going to build it, set it outside to burn.

    Edit: Edit: Maybe it will look good on Youtube. Sarcasm:)
     
    Last edited: Oct 11, 2013
  6. killivolt

    killivolt Well-Known Member

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    Thanks, Ron for all your help and encouragement.

    I'm going to be so bored tomorrow at the festival? What else would you do, I will play some guitar, talk with me buddies on ETO and get some required away time from work. Then back to it on Monday at work and back to this Monday Night:)

    Edit: Second supper is alway's good, just like Second Breakfast:)
     
  7. ronsimpson

    ronsimpson Well-Known Member Most Helpful Member

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    Found a problem. You have a timing cap of 0.0033F and you want 0.0033uF. That is why the osc is not happy. It is still not happy but better.

    Also you have some 0.1F caps. They should be 0.1uf

    I just found another problem. Your timing cap has 220 ohms. I was looking at the ramp and said to my self 'looks like there is a resistor in series with the cap' and I clicked on the cap and there it is.

    Also all your little caps around the IC have the same resistance. Remove the resistance and the osc functions.
     
    Last edited: Oct 11, 2013
  8. eTech

    eTech Active Member

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  9. killivolt

    killivolt Well-Known Member

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    I did it, it's oscillating.

    Rev.4.4 I don't know if any work is being done or not, but I finally see oscillation.

    Edit: I made changes to Rev4.4 as directed by Ron.
     

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    Last edited: Oct 12, 2013
  10. killivolt

    killivolt Well-Known Member

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    Thanks, eTech. I think I'll put the Cap back in as well as the Diodes on the original Schematic and see what happens. I think I'll also use the same values of resistors on RT and the same core for the HV Secondary and see what happens next?
     
    Last edited: Oct 12, 2013
  11. eTech

    eTech Active Member

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    Hi

    Keep in mind L5 R5 and R6 are just there to support the simulation, that's why I labeled it "Flyback Dummy".

    Also, I don't have a lot of faith in the SG3525 model..

    eT
     
  12. killivolt

    killivolt Well-Known Member

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    Ok, finished and now I'll post but, I haven't ran this simulation yet. I'm just using ETO as the repository. This now has the 4 diodes shown in the original schematic and also the Capacitor in the Primary of the GDT.

    Rev4.4.1
     

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  13. killivolt

    killivolt Well-Known Member

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    Right I'm just wanting to see if the original schematic could hold up in the virtual world, before I attempt a build. Next, I want to have a crack at (Chris's 2 Winding Primary GDT.)
     
  14. ronsimpson

    ronsimpson Well-Known Member Most Helpful Member

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    KV,
    C6,7,8,9 I changed to 47uf 170m ohm. It is taking a very long time for the design to 'converge'. Power supplies do not operate right for some time after power up. By changing to 47uF it takes 5mS for the supply to stabilize. There is too much ringing in the LC so I reduced the Q. C6-9=170m ohms and HV primary =50m ohms. Other wise it takes millions of cycles to see how this thing will operate.

    Also I connected the top MOSFET-gate.

    It is operating how I think it should. Probably should have diodes on "outA" and "outB".
     
  15. killivolt

    killivolt Well-Known Member

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    You mean my top MOSFET - gate in Rev4.4.1? or a previous drawing?
     
    Last edited: Oct 12, 2013
  16. killivolt

    killivolt Well-Known Member

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    Hey, Ron you'll need to go to your CMD file in library and open up the Diode section and paste this in to the editor, to make my 1n4007's work.

    File 1n4007..

    Code (text):
    .model 1n4007 D(Is=7.02767 Rs=0.0341512 N=1.880803 EG=1.05743 XTI=5 BV=1000 IBV=5e-08 CJO=1e-11 VJ=0.7 FC=0.5 TT=1e07 KF=0 AF=1)
     
    Last edited: Oct 17, 2013
  17. killivolt

    killivolt Well-Known Member

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    I ran the Simulation on (Rev4.4.1) it build it slowly at 50ms took about 4 minutes but it seems to look ok to me, I just don't know to setup sweeps and stuff to really see the waveforms. I just have some scratchy vertical line smashed in on one another with occasional spikes at the top, when I'm looking at the amps of Pin4.
     
  18. killivolt

    killivolt Well-Known Member

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    Going to the Store now, BBL.
     
  19. killivolt

    killivolt Well-Known Member

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    This is the drawing that I came up with, which is not different from the original design. It seems to work, but the waveforms don't fit the original LT Spice Model in post #87.
     

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  20. ronsimpson

    ronsimpson Well-Known Member Most Helpful Member

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    Your top MOSFET has the gate connected to S. It does not work. The way you have things the voltage on C6,8 will drop to zero (slowly). This will stop working when the voltage approaches zero.

    I connected the gate (again) and it seems to work.

    If you want more voltage change L5 to 1.65mH.
     
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  21. killivolt

    killivolt Well-Known Member

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    Hey, Ron both MosFets were connected on source like that, alec_T had L5 at 10mh, I'll play around with the values.

    Thanks for the catch, I keep using old drawings and didn't catch the flaws.

    kv
     

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