A pickup (aka: VR, Variable Reluctor, Reluctor) is a sensor that have a signal wires and a ground wire.
It’s made of a coil of wire wrapped around a magnet.
When a ferrous part passes by the magnet, the magnetic field is modified and a voltage pulse is created in the coil generating a sine wave.

DCCDIv12 has:
– 1 input for inductive pickup (VR/pickup coil) with 1 signal per crank revolution. (Pickup must puts out 3 to 100Vac)
– 1 input for Digital sensor (Hall Effect Sensor, Optical sensors even breakerpoints).

– This CDI works with ONE pulse per rev (1 reluctor only like “A” or “B” below)
– This CDI DOES NOT work with multi-pulse pickup (ie 2 reluctors on flywheel: “C” or “D”).
– This CDI DOES NOT work with a missing tooth flywheel. (“G”)

When the bar/magnet on the stator passes in front of the pickup, the pickup generates two pulses of OPPOSITE polarity.

A pickup has 2 wires. If you ground wire number 1, wire number 2 will put out a Positive pulse first when the rising edge comes, then a Negative pulse when the falling edge leaves. I call it PN.
If you ground wire number 2, wire number 1 will put out a Negative pulse first, then a Positive pulse. I call it NP.

Pickup Polarity MUST be Positive then Negative. to work with this CDI.

Check the polarity of the pickup (Negative going then Positive/(I call it NP) or the opposite PN: Positive going then Negative) with a Needle galvanometer (in milliAmp position) while kicking.

If the polarity is Negative then Positive(NP) then the leads are backward, just swap the wires to change the pickup polarity !

Watchout! If the pickup is internaly grounded and output ONLY one wire, you won’t be able to change the polarity.
So if the polarity is NP (Negative first) then you CANNOT use this ignition!

“Pickup Position” is the number of degrees between the very first pulse from the pickup and TDC

To be able to provide the largest advance timing (Example 36° @ 4500rpm) the pickup MUST send a trigger signal BEFORE the piston reaches 36° before top dead center (BTDC).
The “Pickup Position” on the Yam XT600 is 50°. Many Yamahas have a “Pickup Position” of 72 degrees.

This “Pickup Position” is dependent on:
– Where the pickup is mechanically located with respect to TDC?
– Where is the flywheel’s bar located?
– How long is the flywheel’s bar?

“Pickup Position” AKA “Max Advance” = “Base Advance” + “Flywheel’s bar Length”

“Base Advance” value sometime appears is User Manuel.
Length of the flywheel’s bar can be measured this way.

You may measure the “Pickup Position” using a protractor.
or with a caliper and some math.

Optional
– Points, reluctors, Hall sensors, optical sensors can also be used as long as they give only 1 pulse per revolution. They may need an additional pullup resistor.

– 3 wires digital Hall effect sensors need an external pull-up resistor. The default voltage output is equal to Vcc (+5v to 24v). When a magnet passes in front of the sensor, the output voltage goes low and the ignition will detect the RISING edge meaning the trigger moment will be when the magnet LEAVE the sensor.

Models : Hamlin 55100, Allegro A1101-A1104, Allegro old 3141-3144, Honeywell 1GT101DC, SS495, SS49E etc…
Pullup resistor: 370ohm (270 to 1200ohm)

600rpm: 6000rpm:

Video

– If the box starts in RUN Mode, the Led turns ON until a pickup is detected.
As soon as a pickup signal is detected, led blinks in rhythm.
If the Maximum RPM is reached, the led turns off. If minimum RPM is reached, led turns off.

– If the box starts in SETUP Mode : Led blinks 5 times before flashing once every 5 seconds.
When data arrives via WIFI, led briefly flashes.

• Version v11r8c0:
  • POC
• Version v12r1c0:
  • Evolution of V11.
  • [soft] New menu. User can select strokes and cylinders.
  • [soft] 2 timing curves available.
  • [hard] 1 switch to select timing curve.