Hi All,

I have a water flow sensor that has the following spec:

•Pulse output frequency (Hz)= 4.1 x Q where Q=volume flow rate in L/min
•Connections: RED (positive), BLACK (negative), YELLOW (output signal)
•Voltage rating: 3Vdc to 18Vdc at 15mA
•Output rating 18Vdc 30mA open collector (recommended 4k7 pull-up resistor)

I have several QRI's that can take a pulsed input however, I'm not sure about the wiring as other pulsed sensors I've got only use two wires and don't use a resistor.

Can anybody suggest a detailed way of wiring this in ?

- Neil