US 2026/0139989 A1 · APPARATUS AND SYSTEM FOR TANK LEVEL SENSING

Abstract

A tank level sensing system of the invention is used with a capacitive system having a pair of electrodes for capacitively coupling with a tank of fluid. A drive circuit provides a voltage drive signal to the drive electrode and a detector circuit is coupled with the sense electrode for detecting a sense voltage signal. A controller is coupled with the drive circuit and detector circuit to use the voltage drive signal and sense voltage signal for determining a fluid level of the tank. The controller varies the frequency of the voltage drive signal to the drive electrode through a plurality of frequencies and detects the sense voltage signal at the plurality of frequencies. The controller determines a plurality of endpoints at the plurality of different frequencies and selects one frequency for measurement. In one embodiment, the voltage drive signal is a sinusoidal voltage signal. In another embodiment, the plurality of frequencies includes base frequencies in a range of 1 kHz to 200 kHz that are offset with various dither frequencies. An output circuit outputs a signal reflective of the determined fluid level of the tank and provides selectable analog and digital output signals reflective of the determined fluid level of the tank.

Claims26

Dependent claims

A tank level sensing system for determining fluid levels in a tank comprising:

electrodes configured for capacitively coupling with a tank of fluid, including a drive electrode and a sense electrode;
a drive circuit coupled with the drive electrode for providing a drive signal to the drive electrode;
a detector circuit coupled with the sense electrode for detecting a sense signal level from the sense electrode in response to the drive signal;
a controller coupled with the drive circuit and detector circuit, the controller configured for using the sense signal level for determining endpoints for a range of signal levels, the endpoints including a FULL endpoint and an EMPTY endpoint for reflecting fluid levels of the tank;
the controller further configured for varying the frequency of the voltage drive signal to the drive electrode through a plurality of frequencies and determining a plurality of endpoints at the plurality of different frequencies by detecting the sense voltage signal at each of the plurality of frequencies.

2 more elements

A tank level sensing system for use with electrodes for capacitively coupling with a tank of fluid, including a drive electrode and a sense electrode, the sensing system comprising;

a drive circuit configured for being coupled with the drive electrode for providing a drive signal to the drive electrode;
a detector circuit configured for being coupled with the sense electrode for detecting a sense signal from the sense electrode in response to the drive signal;
a controller coupled with the drive circuit and detector circuit, the controller configured for using the sense signal level for determining endpoints for a range of signal levels, the endpoints including a FULL endpoint and an EMPTY endpoint for a fluid level of the tank;
the controller further configured for varying the frequency of the voltage drive signal to the drive electrode through a plurality of frequencies and determining a plurality of endpoints at the plurality of different frequencies by detecting the sense voltage signal at each of the plurality of frequencies.

1 more element

Dependencies are inferred from the claim text.

Apparatus and system for tank level sensing

Life of this patent

Apparatus and system for tank level sensing

Life of this patent

Abstract

Claims26