Fuel or electricity consumption meter for motor vehicles - uses variable inductance fuel flow sensor and rev counter output in digital form to compute rate of fuel consumption

摘要

Since fuel consumption meters and rev counters may both use ammeters of rottmeters it is feasible to use the same device to show either the speed of the engine or the fuel consumption. A switch is used to connect the meter to the appropriate sensing element. A digital system may be used to compute the ratio flow: speed or speed:flow in selected units of consumption, using speed and fuel flow data into digital form. The fuel flow sensor may be simplified by using a variable cored inductance to measure the flow of fuel. A winding (1) is made around a tube in series with the fuel channel. The core (2) position is a function of the fuel flow, and the value of the inductance is then a function of the fuel flow. The inductance is included in an oscillator circuit.