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  1. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    I actually did exactly as he said, see 2nd line of #69, he said the schematic is correct, then he also told me to try 100k. So I did two circuits one with 1k (yes it's not 10k because I already did...
  2. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    Yes I understand the scr is a current driven device.

    Like BJTs are current driven transistors where MOSFETs are voltage driven. So scr firing is about current amount, and the discharging is the...
  3. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    Highest current rate possible, if the voltage is so high it could cause a high current spark.
    When I work with PC power supplies, I use like 1k ohm/1W resistor to discharge the high voltage...
  4. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    Of course not, I actually learned a lot. Like I thought about the last information you told me that the resistance has to be very low, so I removed the unnecessary resistors and kept the overall...
  5. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    OK, I think I learned something.

    158534

    I simplified the circuit more, no need for all those voltmeters, because they give rms value. I can now know what's going on with the scope.

    In this...
  6. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    Hi,

    I modified the circuit a bit.


    1. Measuring the signal at the gate, is negative with one scope probe. Why ?

    My understanding here, is that the AC has two branches to run in. Path 1 is...
  7. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    oh yeah .. thanks :)

    really fundamental things.

    I really should have thought of that .. it's an ac signal. And the value in the voltmeter is the rms value ! It's a huge different thing !

    One...
  8. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    Yeah, first I get the warning, but after some time I get the fatal error.

    I know that there are differences between the real and simulation, but I think warning means that there is something not...
  9. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    Yep I did it !

    158505

    But:
    1. I can't get the scr to full conduction.
    2. I get simulation warning.
    3. Gate current is 10mA where it should be > 50mA.
    4. After some time I got simulation...
  10. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    Yes that's correct and I'm putting two simulations side by side, one has the load on anode and the other on the cathode.




    Because of scr output.

    With load connected on cathode, I get the...
  11. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    I didn't understand that completely, it would take me time to understand specific process of triggering the scr.



    I think I go the idea, that it's about the time of charging the capacitor and...
  12. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    How about these ones I found on Aliexpress:
    ...
  13. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    I want to know the type of the capacitor ? is it ceramic, electrolytic, polypropylene .. etc ?

    There are cheap caps on aliexpress that work on high voltages +240V.




    Yep I know that I know...
  14. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    Yep, OK but when I don't put a ground the output signal doesn't clear any sense and really different than anything know about rectifiers.



    yeah .. well ! I don't know almost all circuits that...
  15. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    I followed a method on this website, and it worked but I think there's something different about Proteus simulation.

    https://www.electronics-tutorials.ws/power/thyristor-circuit.html

    I works...
  16. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    I really didn't understand anything ! What I understand and what I got in our actual laboratory oscilloscope is the same thing in the manual which is the positive half cycles. And what is mostly...
  17. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    I thought I only can measure output signal after the cathode.

    I removed the resistor and put the oscilloscope on the anode and it worked.



    the voltage drop on the SCR would be very low; like...
  18. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    Here's my last simulation. It's a simple circuit but I don't know why the thyristor isn't fully activated ?

    158392
  19. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    Put a positive pulse at its gate, connecting the positive voltage of the voltage at the gate and the ground reference to the cathod




    I can't stop it until the voltage between the anode -...
  20. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    I want to do the same exps in the manual I posted in #3, I don't know what hera used in their dev board they provided to our college. It's just closed boards for training.

    So I want to do the...
  21. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    I tried the one with with triac output, but the output voltage went really crazy ! I don't know why !

    158340

    - - - Updated - - -

    I think I need to learn a lot of things in electronics !!
    ...
  22. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    The diode and thyristor types are generic, I'm now trying to reach a level to run the simulation successfully then I would consider the ratings of voltage and current.

    Because it would be...
  23. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    158309

    My last simulation.
  24. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    I found this information on the following link:
    https://instrumentationtools.com/basics-of-thyristor/





    Also this is my current simulation, I don't know why the SCR isn't working ! The...
  25. Closed: Re: Where to get schematics about SCRs full-wave triggering circuits ?

    Yep that's not a very complicated datasheet, simple thyristor with clear ratings.

    I know the basic operation of a thyristor, traic. Diac is not very obvious to me so far, I really don't know why a...
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