This circuit turns an AC-CDI into a DC-CDI.
An AC-CDI needs a working STATOR to charge. If the stator fails, let it be rewind or buy a new one is pretty expensive!
This circuit was designed to bypass the faulty stator by making High Voltage (around 150 to 400V) directly from the +12v battery.
When the internal SCR of the AC-CDI has been latched in ON state for a spark, only the voltage crossing a falling zero will turn it OFF again. In order to let the SCR return to blocking state, this circuit alternates ON and OFF states.
- 50 to 20,000 RPM
- 10 to 60mj
- Power supply voltage DC 12 volts
- Current drain: 60mA to 1.3A
- Output voltage: 180 to 400Vdc
- Kill switch
- 1.5A resettable fuse for Thermal and overcurrent Protection.
- Ferrite choke to suppress HF electronic noise in electronic circuits.
- Common ground between 12Vdc and HV
- Dimensions: 75 x 50 x 25mm (3 x 2 x 1 inch)
Wiring to an ACCDI
FRQ solder pad:
If open (default): Frequency of the circuit is 1000Hz (equal to 6 pulses/rotation at 10000RPM)
If close: Frequency of the circuit is 500Hz (equal to 3 pulses/rotation at 10000RPM)
PWM solder pad:
If open(default): HV generator alternate ON/OFF period at 50% (Maximum output voltage = +300Vdc)
If close: HV generator alternate ON/OFF period at 33% (Maximum output voltage = +200Vdc)
– When the module is powered on, LED blink 3 times meaning processor is OK.
– Led is OFF when output voltage is OK (not too high)
– Led turns ON when output voltage is too high and overvoltage regulation works.
– Led stays ON when KILL input is connected to ground to stop the DC generator.
Remove the KILL wire from the ACCDI and connect the Kill Switch to this Power module
If Kill input is connected to Ground: DC generator stops and Led turns ON. (Action Time: 1.5ms)
Over Voltage Protection: Turn the trimmer to adjust the maximum output voltage from +180v until +300v.
Led turns ON when OVP (aka regulation) is active.
Transistors need heatsinks if this unit run at 10.000rpm longer then 1 minute.
Blue: Mosfet Gate. Yellow: DC output
25mj are the minimum to get a spark.
With trimmer at minimum:
With trimmer at maximum:
PHOTOS.Click here for more info
VIDEOS.Click here for more info
- Version V1R2C1:
- First Version.
- Version V2R0C0:
- [soft] Improvements.
- Version V2R0C1:
- [hard] Change PCB layout.
- [soft] 2 PWM DutyCycles.
- [soft] Led blinks at startup.
- Version V2R1C0:
- [hard] Change components values.
- [hard] Change fuse type.
- [hard] Add self to avoid EMI noise.
- [hard] SMD components.