Differences between pointless electronic ignition and capacitor discharge ignition

[bertosthailand]

How is the differences between pointless electronic ignition and capacitor discharge ignition?

Are they exactly the same ignition system?

Any differences?

[amahaork]

Why don't you study that and present us with your paper comparing two systems and express your personal opinion.

[ausnoelm]

Are you talking about an ignition system, with a distributor, but no points compared to an ignition system that has no distributor??

[bertosthailand]

Dear Sir

I have seen in the specification that Yamaha outboard using CDI system. On the other hands, Suzuki has pointless discharge ignition.

That why I m wondering how differences between these two system.

[rodbolt17]

bold new graphics.
it is all marketing hype.
there are only so many ways to turn on and off ign coil primary current.

[boscoe99]

How is the differences between pointless electronic ignition and capacitor discharge ignition?

Are they exactly the same ignition system?

Any differences?

They are not the same. There are differences. Big differences.

In a conventional (most common) ignition system a battery and an ignition coil are used. Battery current flows through the coil. The current is made to stop flowing through the coil at which time a spark is made to jump across the spark plug gap.

There are two basic ways to stop the current flow through the coil. One way is for a set of points (switch contacts) to open. This is mechanical. The other way is for an electronic switch to stop the current flow. This is what is referred to as "pointless ignition". The points have been replaced by electronic gizmos.

In a capacitor discharge ignition (CDI) system a battery is not used. A magnet on the flywheel of the motor creates electricity and sends that electricity to a capacitor. The capacitor stores the electricity for a moment, just like a battery might. At the right time the capacitor dumps all of its electricity into an ignition coil. The current flowing into the coil
causes a spark to occur at the spark plug gaps.

Two different ways to spark the plug. Each has its pros and cons.

Some Yamaha's use CDI ignition whereas other Yams use a pointless discharge ignition. Yamaha's calls their a "transistorized" ignition system. I suspect that some Suzuki's also use a CDI ignition system. Whatever each manufacturer is calling their system is mostly marketing crap. The engineers have designed into each particular motor model the type of ignition system works best, for that particular motor.

[fairdeal]

Battery current flows through the coil. The current is made to stop flowing through the coil at which time a spark is made to jump across the spark plug gap.


At the right time the capacitor dumps all of its electricity into an ignition coil. The current flowing into the capacitor causes a spark to occur at the spark plug gaps.

I think you meant to type "coil" there?

regardless, here's my questions:

clearly the CDI is a "pulse" application of current to the coil
but it seems that under actual rpm conditions, the points are effectively providing only a "pulse" ?

and in both cases, it is the "collapse" of the magnetic field that causes the spark?

[boscoe99]

I think you meant to type "coil" there?

regardless, here's my questions:

clearly the CDI is a "pulse" application of current to the coil
but it seems that under actual rpm conditions, the points are effectively providing only a "pulse" ?

and in both cases, it is the "collapse" of the magnetic field that causes the spark?

Yep. I meant the coil. Message corrected.

In one system the collapse of the magnetic field in one coil (at 12 volts) due to stopping current flow causes high voltage to be created in the other coil which then causes the spark.

In the other system the application of high voltage to one coil causes high voltage to be created in the other coil which then causes the spark.

In both coils there is a change in voltage. One diminishing quickly whereas in the other it builds up quickly. End result (the spark) is the same. Although the qualities of the spark are different.



Ignition System Coil - How Automobile Ignition Systems Work | HowStuffWorks