Two Stroke CDI (Capacitive Discharge Ignition)
The next schematic shows the coil configuration at magnetic plate and the position of the pick-up at the outer sider of the plate. This pick-up is triggered by the step on the plate. Below are shown the signals measured by means of an oscilloscope at the output of the magetic plate, and the output of CDI for the primary of the HV coil.
detail
Saturday, March 11, 2006
Subscribe to:
Post Comments (Atom)
1 comment:
the trigger is controller by means of a microcontroller, in this case PIC16F84 of MicroChip. This micro has a FLASH memory that can be saved with a simple programer that you can build easily, all information about the programmer can be found at JDM.
PIC receives the signal from the pick-up and delays it by using an internal table. This means that the starting point of the ignition should be place before of PMS at the most advanced point in wich you want to the ignition works.The PIC computes the elpased time between the last pulse and the present one, and by using this count it access to a table in which are stored time to delays vs measured period.
* Schematic is designed to enable starting whithout battery.
* It is assumed that the pickup generates a double pulse.
* the first pulse (the negative one) is catched with the optocoupler to be processed by the PIC.
* The second pulse (the positive one) is sent directly to the SCR (thyristor) to enable starting when the PIC has not current yet.
* At least a 24 degree delay is required from the first pulse to the second to enable this configuration to work.
-Dan
ignition module
Post a Comment