Coils 101
08-19-2003, 04:19 PM
#1
Safety Car
Thread Starter
Coils 101
I know this isnt a stupid question but im looking for a technical explanation. So how does an ignition coil take a 12v power source from the battery and convert it into a 40,000 volt charge for the sparkplug? Is it converting high amp 12v into low amp 40,000v?
08-19-2003, 04:49 PM
#3
Team Owner
Re: Coils 101 (Jvette73)
Ok, consider the coil as a crazy sort of power transformer, similar in concept to the one's that run oon power poles for your house currents, off the 4-12kv lines running through the neighborhood...that line up top the poles with the large ceramic insulators on it....
they both have iron cores, and a certain number of turns on it...ONE set is called the primary, the other set is the secondary, and any others are loosely termed tertiary (ies).....
so in this case we only have two sets of windings, and if the input (primary) wiring has 100 turns on it, and the secondary has 1000 turns on it, you will say feed 10 volts into the primary, you will get 100 volts out of it....it's a function of the TURNS RATIO, input to output, simple as that....
so if the 12 volts side has say 120 turns, the seconday side would have 400,000 turns, basically....
BUT remember there is NO free lunch....POWER expressed in watts, or volts x amps.....input is allways nearly equal to the output in volts x amps....so you have to know the amps at 40 kv is VERY small...enough to jump the gap under compression and ignite the fuel efficiently....
ALL transformers work on the same principal....
NOW the wave shapes and forieir transforms, areas under the curves and waveform analysis of the breaker point ignitions, and DFEDT are another discussion for EE school....
GEN
they both have iron cores, and a certain number of turns on it...ONE set is called the primary, the other set is the secondary, and any others are loosely termed tertiary (ies).....
so in this case we only have two sets of windings, and if the input (primary) wiring has 100 turns on it, and the secondary has 1000 turns on it, you will say feed 10 volts into the primary, you will get 100 volts out of it....it's a function of the TURNS RATIO, input to output, simple as that....
so if the 12 volts side has say 120 turns, the seconday side would have 400,000 turns, basically....
BUT remember there is NO free lunch....POWER expressed in watts, or volts x amps.....input is allways nearly equal to the output in volts x amps....so you have to know the amps at 40 kv is VERY small...enough to jump the gap under compression and ignite the fuel efficiently....
ALL transformers work on the same principal....
NOW the wave shapes and forieir transforms, areas under the curves and waveform analysis of the breaker point ignitions, and DFEDT are another discussion for EE school....
GEN
08-19-2003, 06:01 PM
#4
Melting Slicks
Re: Coils 101 (mrvette)
Turns ratio is correct.Input versus output ratios can give you any voltage out you want,but as previously stated the total energy (VA,or watts) is the same on both sides(give or take a loss due to eddy currents and heat losses)
08-19-2003, 06:32 PM
#6
Re: Coils 101 (mrvette)
Nice one mrvette.
Also remember that there is no such thing as 100% effieciency in power conversion, there will always be some power lost in the coversion process.
Also remember that there is no such thing as 100% effieciency in power conversion, there will always be some power lost in the coversion process.
08-19-2003, 07:17 PM
#7
Re: Coils 101 (Boofers)
keerekt. That is why your coil gets hot when in use.