A
Addy Leung
Guest
After read through the Suzuki service manual about the full transistor ignition unit, I now understand that the creation of a spark over the spark plug is the result of cut of the primary side current of the ignition coil, like the dyan 3ome coil, in this cut off processes, the secondary side of the coils will create an induced voltage, so that a spark over the spark plug gap. The strength of spark is depend on a equation if I still remember what high school learned, it is equal to the inductance (L) of the coil x di/dt , i is the current at primary side of the coil, t is the time to shut off this current. I don’t want to explain the equation here but just want to discusses here how the to make a stronger spark by improving the elements of this equation.
What I think it is if we reduce the primary coil resistance ( let say from 3 ome to 2.2ome) or increase the system voltage or say the charging voltage ( from 13.5v to 14.5v), it will increase the current. However, a lager current may kill the transistor of the ignition unit. ( in stock ignition unit or Dyna unit, the primary side current is driven by the system DC voltage not by the ignition unit. I = DC voltage / resistance of the coil, e.g. I = 13.5/3= 4.5amp)
We can also increase the inductance of the coils to get a higher induce voltage as L x di/dt = induce voltage = stronger spark. However, a higher inductance need more turn of coils and more turns of coils will result in increase the DC resistance of the coil, that result of decrease the current , and also the physical size of the coil will also be increased.
We can also decrease turn off time of the primary current but it will really depend on the characteristic of the design of the pickup coils and the ignition unit.
What do I really think about is more practical is that we make a higher stand along 3 phase AC to DC voltage regulator supply unit ( let say 20dcV, in fact it is very easy to made one if it do not need to regulate for charging system, only DC power supply) by parallel tee off the 3 yellow wires from the alternator and it only supply the ignition coils. Do you think it is possible?
What I think it is if we reduce the primary coil resistance ( let say from 3 ome to 2.2ome) or increase the system voltage or say the charging voltage ( from 13.5v to 14.5v), it will increase the current. However, a lager current may kill the transistor of the ignition unit. ( in stock ignition unit or Dyna unit, the primary side current is driven by the system DC voltage not by the ignition unit. I = DC voltage / resistance of the coil, e.g. I = 13.5/3= 4.5amp)
We can also increase the inductance of the coils to get a higher induce voltage as L x di/dt = induce voltage = stronger spark. However, a higher inductance need more turn of coils and more turns of coils will result in increase the DC resistance of the coil, that result of decrease the current , and also the physical size of the coil will also be increased.
We can also decrease turn off time of the primary current but it will really depend on the characteristic of the design of the pickup coils and the ignition unit.
What do I really think about is more practical is that we make a higher stand along 3 phase AC to DC voltage regulator supply unit ( let say 20dcV, in fact it is very easy to made one if it do not need to regulate for charging system, only DC power supply) by parallel tee off the 3 yellow wires from the alternator and it only supply the ignition coils. Do you think it is possible?
