Connect with us

wiring triac to ignition coil

Discussion in 'Electrical Engineering' started by ulyx, Dec 12, 2006.

Scroll to continue with content
  1. ulyx

    ulyx Guest

    Hi !

    I need to discharge 10uF - 300V capasitor to ignition coil thru triac.
    This should trigger ( in best case ) ignition coil to produce high voltage.

    Can someone show me how to connect this?.
    Am still in high school ( first class ) so take this into considiration :).

    Thank you in advance !
     
  2. Guest

    Sounds more like a job for an SCR. Just remember the "plus" juice
    comes out the end with the plus sign on it (plus goes in the other
    end). That will get you polarizing your diode the right way. Then
    trigger the SCR (basically a triggered diode) with a plus signal. It
    will conduct until the capacitor is discharged. Rinse repeat.
    The next thing you have to figure out is how you charge the capacitor
    and what triggers the SCR.

    This is pretty much opposite of how an automotive ignition really
    works. They discharge the capacitor while charging the coil and the
    shot comes when you open the charging circuit and allow the coil flux
    to collapse across the capacitor.
     
  3. ulyx

    ulyx Guest

    ** The next thing you have to figure out is how you charge the capacitor and
    what triggers the SCR.**
    Im charging capasitor thru DC source with cca 2V ~ 80uA and i need some time
    to charge this capasitor. In "few" :) hours capasitor is charged with 300V
    DC.
    Capasitor charging time is not importent to me. The main thing is to trigger
    the ignition coil.


    ** SCR: **
    Which thyristor model would you use ?


    ** question: **
    If i connect 300V thru thyristor, on 12V ignition coil.... will this not
    break the isolation in ignition coil ?
    I meen, you will have greather voltage on secundary side.


    ** Schematics **
    Can you be please so kind to send me some basic schematics on this, before i
    make something wrong :) ?
    I have read what you have writen about wireing, but some schematic would
    help me to understand this.


    Thank you in advance !
     
  4. Yes. The high voltage pulse is effectively the back-emf (transformed
    up) which results from stopping the coil current very quickly. It is
    much harder to do this by discharging a capacitor through the coil
    as the coil's inductance will stop such a rapid rise in the current,
    so the rate of change of magnetic flux will be lower, resulting in
    a lower output voltage.
     
  5. ulyx

    ulyx Guest

    OK. now i know that i can make this :)
    Please be so kind and send some full basic schematic so i can make wiring.

    Thank you for your time and kind answer !
     
  6. Guest


    What are you making? That will make it easier to get help.

    The reality is, it is hard to beat a set of points and a capacitor for
    simplicity and reliability. In a car on the highway those points will
    make and break ~3/4 million times an hour. (V-8 at 3000RPM)
     
  7. ulyx

    ulyx Guest

    What are you making? That will make it easier to get help.
    * I have one school project and this is what i HAVE to do.

    Input: charged 300v ~ 20uF capasitor
    Output : HV output from ignition coil

    --------------------------------------------
    This is how i would make it:

    Capasitor
    Thyristor connected to ignition coil
    Ignition coil starts
    HV will be generated
    Saving this high voltage for something else ( * this is just as additional
    option )
    ---------------------------------------------
    So, the main thing is that ignition coil should generate this HV and
    regarding to capasitor power this should go.

    I will not give up, I will not give up, I will not give up, I will not
    give up, :))
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-