Patent ID: 8199021

Claim:
A fluid level detection system comprising: a fluid reservoir defining a cavity for holding fluid therein; a fluid level sensor having a solenoid body mounted to the fluid reservoir with a first portion extending inside of the cavity and a second portion extending outside of the reservoir, a coil, and an armature; wherein the solenoid body defines an armature chamber in which the armature travels in response to energizing of the coil; a pole piece; a biasing device biasing the armature away from the pole piece, the biasing device and coil being configured to cycle the armature in the armature chamber as the coil is cyclically energized; wherein the solenoid body defines a first opening establishing fluid communication between the armature chamber and the cavity defined by the reservoir, travel time of the armature within the armature chamber thereby being affected by fluid level in the reservoir; wherein the sensor is operable to provide a sensor signal indicative of the travel time; a controller operatively connected to the sensor and operable to receive the sensor signal from the sensor and formulate a control signal corresponding thereto; and a power source operatively connected to the controller for energizing the coil and the controller.