wiring triac to ignition coil

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.

** 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 !

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.

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 !

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)

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, :-))

That may be the situation for a conventional system using points to interrupt the current, but high MAGNETIZING inductances helps to couple the capacitor to the spark plugs.

Bill

-- Fermez le Bush