Patent attributes
A liquid level control module comprising an elongated tubular housing immersible through a surface of a liquid and into a bulk volume of the liquid, and first, second, and third electrical switches, and first and second floats movable along the tubular housing. The first electrical switch is disposed within a lower portion of the tubular housing, the second electrical switch is disposed within an intermediate portion of the tubular housing, and the third electrical switch is disposed within an upper portion of the tubular housing. Each of the switches has an open state and a closed state. Motion of the first float relative to the first switch changes its state. Motion of the second float relative to the second switch changes its state, and motion of the second float relative to the third switch changes its state. Thus a two-float module may provide three level control signals.