Page 6 of 20
Pulser Wiring Instructions - Models M,F,S and CR - If fitted with cable
Sensor Wiring Connections if flow meter fitted with cable
Reed Switch is a 2-wire device which triggers by magnet
inside the rotors as they spin. To maximise the life of the
reed switch, the pulse board comes equipped with a 1.8
kΩ current limiting resistor in series.
Hall Effect sensor is a 3-wire device which triggers by
magnet inside the rotors as they spin. This sensor is NPN
type (current sinking, open collector). The sensor circuit is
equipped with a 4.7 kΩ pull-up resistor between signal
and supply.
This in-built pull-up resistor can be bypassed by moving
the jumper pin to the off position if required.
A pull-up resistor of your choosing can be installed be-
tween signal and supply, provided the in-built pull-up resis-
tor be bypassed first.