Project on Jectronic Alfa Romeo 1.8 Turbo

[christian_piasini]

Hello everybody on the forum.

I have a question about the RPM input signal connection on the pilot PCB board, and also about the configuration.


alfa romeo 75 use bosch distributor HALL with 4 windows @ 720 cranckshaft degree.

i saw that older verion USB pilot PCB board has 3 pad on the board to connect the rpm signal, i want know if the same pads on the Bluetooth pilot are possibile to use.

i saw that don't have from factory the pins to connect but need soldering.

just want be sure before connect on it.

thanks to everybody

Best regards

Christian Piasini

[christian_piasini]

details pictures

CP

[christian_piasini]

adding details about the trigger sensor HALL on distributor

pinout is


1. - ground
2. signal output
3. +12v


BR

CP

[Pin]

Hello.
You can try to connect it to pin A
via voltage divider ( two resistors 10k , one is connetced to hall sensor , other to ground and signal from central point to pin A)

[christian_piasini]

Hello.
You can try to connect it to pin A
via voltage divider ( two resistors 10k , one is connetced to hall sensor , other to ground and signal from central point to pin A)


Hi Pin,

why i need to use divider voltage ???

my output hall signal is already 5volt output, as can see on the oscilloscope drawing !!!

please let me know


BR

Christian

[Pin]

Hi.
You can try to connect it directly , but in some cases as there is low internal impedance of this input of the converter, signal from hall sensor can lost an amplitude and engine will not start and work.
But if you will connect it to the converter and amplitude of this signal stayed the same - you dont need to make a divider.

[christian_piasini]

i have already done it, and it work ok.
not sure if rpm match the right rpm, i guess it's about -20% less then right engine rpm

i have engine running 850/900 and reading on the pilot software is 680/ 710 rpm

any idea about that ?

BR

CP

[Pin]

By default factory firmware is for 6 cyl (calculate RPM for 6-cyl engine ).
As you use 4-cyl engine, you need to update firmware to 4 cyl engine firmware.