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Posted: Tue Nov 06, 2007 3:40 pm
by ChemCool
NO, explain the 120v? Why 120 v?
Posted: Tue Nov 06, 2007 3:43 pm
by ChemCool
The 12v you would rather use to trigger the power transistor and the power transistor carry the load of the coils.
So why 120v?
You can also trigger a 12 Volt coil with 12v provided the 12V source can deliver the set current. Then that coil can deliver higher output voltage. Similar like NA. You can theoreticaly input that same coil with higher voltage and get more out than the first example, but there are limitations.
So to make up for higher current situations and to seperate more than one coil firing, you make use then of a power transistor to assist. The power transistor can be triggered even with let say 5v, but the power transistor will switch any other applicable voltage to the coil and will keep the current in mind as well. If for that reason this coil can handle an input of 120v(which is not likely) it can be sitched that way, but I dont think this is what you want
Posted: Tue Nov 06, 2007 3:45 pm
by Gary57
So why 120v?
I think he just used that figure to get his point across, could of said 12v or 4v i suppose.
Posted: Tue Nov 06, 2007 3:52 pm
by ChemCool
The 12v you would rather use to trigger the power transistor and the power transistor carry the load of the coils.
So why 120v?
You can also trigger a 12 Volt coil with 12v provided the 12V source can deliver the set current. Then that coil can deliver higher output voltage. Similar like NA. You can theoreticaly input that same coil with higher voltage and get more out than the first example, but there are limitations.
So to make up for higher current situations and to seperate more than one coil firing, you make use then of a power transistor to assist. The power transistor can be triggered even with let say 5v, but the power transistor will switch any other applicable voltage to the coil and will keep the current in mind as well. If for that reason this coil can handle an input of 120v(which is not likely) it can be sitched that way, but I dont think this is what you want
Posted: Tue Nov 06, 2007 3:55 pm
by ChemCool
think he just used that figure to get his point across, could of said 12v or 4v i suppose.
Sure, ok. Just making sure we dont get confused
Posted: Tue Nov 06, 2007 4:08 pm
by Drillergy
The Damn Fifth gear just wont go in!!!!!
What is the problem???
Posted: Tue Nov 06, 2007 4:19 pm
by Draco
I think you should phone and get quotes at gearbox places, I don't think any one of us are able to fix gearboxes, Jay boy did his own but he is not around that much
Posted: Tue Nov 06, 2007 4:28 pm
by Drillergy
I guess you right....
Posted: Tue Nov 06, 2007 6:24 pm
by veecee
ChemCool wrote: think he just used that figure to get his point across, could of said 12v or 4v i suppose.
Sure, ok. Just making sure we dont get confused
i am not worried about the power transistor. that is a constant in the equation.
what i am saying is that i "heard" that if you use a bigger, higher, stronger (whatever) trigger, your coil will output a bigger, higher, stonger (whatever) output!
is this true?
and drillergy, if your gearbox isnt working and you cant do it yourself, then i'm afraid it has to go to someone who can do it. in this case i would recommend a "professional"!!!
Posted: Wed Nov 07, 2007 6:47 am
by Toby
Yes, if you use a "stronger" coil, then it will output a higher voltage and you will get a better spark. The power transistor can't supply more voltage than that power supply (which is about 14V for a car battery, unless a charge pump is used, but I doubt that), so your only option of getting a higher voltage to the spark plug is to use a coil that has more windings (it works like a step-up transformer). Or you could use some electronics jiggery pokery to get the transistor or ECU to supply a higher voltage using one of those amplifier jobbies in the pic ( which will probably use a charge pump or dc-dc converter to increase the voltage to the coil). Bear in mind that the coil is only designed for a certain voltage in the primary windings, so if you increase it, you run the risk of melting the coil, especially at higher RPM's.
Posted: Wed Nov 07, 2007 7:03 am
by Vlade
If you look at what the ignition amplifier does, it provides more juice for the coil... the ECU can't provide 30Amp per channel continuously so the more amperage available to the coil the better the spark will come out even at high RPM, since at high RPM (8000) there is roughly 33 sparks ignited every second per channel, thus the ignition amplifier must be able to provide enough amperage and quickly enough for a coil to spark to its full potential...
Voltage don't matter, the ignition amplifiers are triggered with very little voltage and at low current, but they amplify power drawn from the battery.
