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Various pickup / sensor installation possibilities
Note: On Rotax DCDI
ignition systems it
may be required to
install a ballast
resistor as shown. A
typical value is 220
ohms. Many
installations can
omit this.
Typical hall effect
sensor installation
detects the passing
of a magnet suitably
fixed to prop flanges
or shafts.
The gear tooth
sensor is a popular
pickup used on the
pre-rotation gear of a
gyro plane.
(rotor speed
indication)
The optical reflective
pickup can provide a
simple means of
contactless RPM
sensing in difficult
installations.
RPM
GROUND
+5VDC
RPM
GROUND
+5VDC
RPM
GROUND
+5VDC
RPM
GROUND
+5VDC
Grey rev counter wire
Brown wire
(engine block - ground)
Ballast
resistor
Rotax DCDI setup (Ballast resistor optional)
Magnetic pickup with Hall effect sensor
2K2 resistor
Magnet
Hall effect sensor
Magnetic pickup with active gear tooth sensor
1K resistor
Honeywell gear tooth sensor
Optical, reflective sensor
220, 330 or 560 ohm resistor
2K2, 3K3 or 4K7 resistor
Red
White
No marking