Convert ACCDI into DCCDI

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.

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• 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)

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Diagrams
Wiring to an ACCDI v2.6
Wiring to an ACCDI v2.7
KIT: DC converter pinout

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Jumpers
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)

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Led
– 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.

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Kill switch
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)

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OVP
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

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Power

25mj are the minimum to get a spark.
With trimmer at minimum:

With trimmer at maximum:

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PHOTOS.

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VIDEOS.

Click here for more info

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VERSIONS

• 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.

• Version V2R1C1:
  • [hard] Change components values.
  • [hard] Add capacitor to smooth the output voltage.