We start from pickup coil, when the tooth approaches a pickup coil,the magnetic field in
the pickup coil changes, and an AC signal voltage is induced in the sensor coil/pickup
coil. This signal transmit to control the SCR with resistor and capacitor(parallel R1 and
C1 for adjust the advance timing), SCR turn ON and OFF if receive this signal and make
the voltage on anode the SCR turn ON and OFF appropriate input the SCR. This cycle
make the capacitor(C2) charge and discharge to switches an ignition coil and make the
field magnetic and produce high voltage to secondary ignition coil, this high voltage
supply to spark plug.
Component this circuit:
• R1=22K ohm
• R2=1K ohm
• C1=3,3 uF/50V
• C2=1 uF/400V
• D1,2,3=IN4007
• SCR=2P4M
The simple ignition just produce results like above picture, the linear advance with RPM,
we can not adjust the advance timing, because we use the parallel R and C for adjust
advance timing for this CDI ignition. We can be adjust the advance timing with advance
module like below picture.
The purpose advance module as this circuit is adjuster advance timing, with change delay
of time charge and discharge of capacitor C2, if the positive signal come to the module,
the module switch ON the SCR, and delay some time to switch OFF. This function to get
accurate the ignition timing appropriate RPM of engine. We get optimum power of
engine ( acceleration and top speed can be maximum) if the timing ignition is accurate,
acceleration begin 1500RPM, top speed over 2500Rpm, not misfire and knocking this
make to damage the engine. The flexible and easy to adjust the advance timing, we must
to use the programmable ignition or read here to learn more the programmable ignition
or jump to Easy To Build CDI (2)
Tags: CDI, Motor Cycle, Programmable Ignition
By Otto http://www.Auto-Report.SJboygroup.com
