초록 ▼

An electrically resistive fluid level sensor and system for sensing fluid levels in a container, for example washing machine basins, and for closing a supply of fluid to the container when the fluid level in the container reaches a specified level. The system includes generally fluid level resistive

An electrically resistive fluid level sensor and system for sensing fluid levels in a container, for example washing machine basins, and for closing a supply of fluid to the container when the fluid level in the container reaches a specified level. The system includes generally fluid level resistive element portions disposed in the container and electrically connectable by fluid therein, and an input signal source, electrically coupled to the fluid level resistive element portions, whereby an output signal across the fluid level resistive element portions is proportional to the fluid level. Temperature resistive element portions are preferably disposed in the container and connected in series between the input signal source and the fluid level resistive element portions to substantially cancel any thermal effects on fluid level sensing and control. The fluid level resistive element portions are electrically coupled to a signal input of a comparator circuit, whereby an output signal of the comparator circuit closes the supply fluid to the container when the fluid therein reaches a specified level.

대표청구항 ▼

[ What is claimed is:] [1.]1. A fluid level sensing system useable for sensing the level of conductive and partially conductive fluids in a container, the system comprising:a first elongated fluid level resistive element portion disposed substantially vertically in the container;a second elongated f

[ What is claimed is:] [1.]1. A fluid level sensing system useable for sensing the level of conductive and partially conductive fluids in a container, the system comprising:a first elongated fluid level resistive element portion disposed substantially vertically in the container;a second elongated fluid level resistive element portion disposed substantially vertically in the container;a first elongated temperature resistive element portion disposed substantially vertically in the container;a second elongated temperature resistive element portion disposed substantially vertically in the container, a second end portion of the second elongated temperature resistive element portion electrically coupled to a first end portion of the first elongated fluid level resistive element portion;an input signal source electrically coupled to a first end portion of the first elongated temperature resistive element portion;the first and second elongated temperature resistive element portions and the first and second elongated fluid level resistive element portions electrically connectable by fluid in the container,whereby an output signal across the first and second elongated fluid level resistive element portions is proportional to a fluid level in the container, and the first and second elongated temperature resistive element portions offset variations in the output signal resulting from variations in temperature.