that is the CDI unit from a pitbike, a lifan, a... anything small, fourstroked and with a seperate trigger coil. they also make no difference to the performance of said engines, and if anything...are delicate and easily FRIED. i particularly like how the label has some type of curve, one axis labelled in PS (basically horsepower but more german) and the other axis is in KM/h! which has nothing (other than gear ratios) to do with engine speed!
an advance curve is measured as degrees from TDC over RPM.(top dead center, revolutions per minute)
whats a trigger pulse?
well... in a CDI system, theres two coils, one produces a large voltage, which is used to charge a capacitor (the C from CDI...capacitor discharge ignition)
the second, small coil is located in the right place in regards to TDC. once the capacitor is charged, when this small coil produces its low voltage, the capacitor is dicharged through the (ignition) coil, producing a spark.
a HT CDI is fundamentally the same, but uses only one coil... it produces AC electricity. the capacitor is charged on, say, the POSITIVE cycle, and is discharged as the voltage on the NEGATIVE cycle reaches a certain threshold.
most "performance" cdi units for the HT simply alter the trigger voltage on the negative cycle, that can be used to change the advance curves, by using what are called CR delay circuits, or... a capacitor and a resistor. the resistor affects how fast the capacitor charges up. (this is NOT the main discharge capacitor, mind you!). this can "delay" the trigger point, which creates RETARDED spark. the standard HT cdi keeps ADVANCING, and 2 strokes dont like that much, requiring at a certain point...retarding of the spark.
ha ha, retard
no, you CANT redesign the CDI unit you have pictured. sorry
