DC-CDI based on 16F628.
Synoptic:
Principle.
The CDI part (Capacitive Discharge Ignition) has been
described in the page "fixed
ignition".
The sensor is connected between X2-1 and X2-2
The pulses coming out from this sensor (the 36° sensor in the
case of
the XT) trigger the optocouplor 4N35 through R8 which limits the
current to 20mA (adjust the value of R8 if required), zener D1 which
limits the tension to 18v.
The optocouplor provide a 5 volts pulse to the PIC input (pin 9).
A pulse delayed according to the advance curve programmed into the PIC, is available on pin 18 and trigger the thyristor T1 via R9, C8, D3.
2 FLPS units convert the 12Vdc to about 600Vac.
The 2 units are connected in parrallel in order to double the power and
thus to double the maximum frequency. (90Hz with only one module, and
180Hz with 2 modules and so on...).
In addition, the redundancy of the modules ensures a safety, if a
module failed, the engine continue to run with only one module.
The 2 tensions are rectified by the bridges B1, B2. We get a tension of approximately 740Vdc at the exit of the bridges, that charges the C11 condensator.
The high voltage from alternator is thus not necessary.
Software.
| PDM1.31 | Source .HEX (ASM unavailable) |
| DC-CDI 2 strokes 50cc 3446 -> 13020rpm |
pwmv130.zip |
Max Ignition Frequency 180Hz with 2 FLPS units.
This DC-CDI provide sparks until 180Hz, beyond this frequency, the two inverters have not enought time to charge the capacitor.180Hz equal 11000RPM for a one cylinder with wasted spark, or 5500rpm for a 4 cyl.
With 4 FLPS units, the max frequency will be about 360Hz (22000rpm for a one cyl. 11000rpm for a 4cyl)
Schema.
| PDM1.31 | Schema | PCB | Componants | Part list |
| DC-CDI | Schema.PDF | Board.PDF | Components.PDF | Partlist.TXT |
Circuit board.
)
Realization.
FLPS:
Power supply for Cold Cathode Fluorescent
Lamp
input voltage: 12V |
 |
| DC-CDI Version 1.2 |  |
| Tension between ground and capacitor C11 at 140Hz |
 |
| Tension between ground and capacitor C11 at 20Hz |
 |
Versionning.
- Version 1.0:
- Initial release with a little phone line transformer.
- Version 1.1:
- With a 2x6v/220v transformer.
- Version 1.2:
- With 2 to 4 FLPS units.
- Version 1.3:
- Few corrections included
- Version 1.31:
- one correction included