Capacitive level sensor circuit

Abstract

The present invention relates to a capacitive level sensor circuit. The capacitive level sensor circuit for preventing unnecessary and frequent sensing and chattering due to the sloshing of a liquid, according to one embodiment of the present invention, is applied to a capacitive level sensor, which comprises a sensor rod forming a first electrode and a hollow guard pipe separately accommodating a part of the sensor rod and forming a second electrode, and is integrated into a circuit board provided inside the guard pipe and measures a liquid level by sensing a variation in capacitance via the first and second electrodes. The capacitive level sensor circuit comprises: a sensor circuit unit which comprises a capacitor having a predetermined amount of capacitance and a first control unit for comparing the capacitance of the capacitor and the capacitance measured via the first and second electrodes and outputting a high or low signal, and which has multiple communication ports having a clock line and a data line respectively connected thereto; a delay circuit unit, which is connected in parallel to the first control unit via the clock line and the data line and outputs a high or low signal after a predetermined delay time according to the output signal of the first control unit; and an output circuit unit for transmitting a high or low signal to an external output terminal according to the output signal of the delay circuit unit and receiving a DC voltage for circuit operation.

Description

technical field [0001] The invention relates to a capacitive water level detection circuit, in particular to a capacitive water level detection circuit which uses the capacitance difference between a part submerged in a liquid and a part not submerged to detect the water level. Background technique [0002] The technique of measuring the water level of a liquid has been developed from a float instrument method and a magnet instrument method to an electronic instrument method. A superficial example of the electronic water level measurement method is the capacitive method, which is the best method capable of solving both the error rate and the defect rate of the floating instrument method or the magnet instrument method. [0003] The above-mentioned capacitive water level detector has attracted attention in terms of precision and economy, such as figure 1 As shown, it includes: container main body 1, which is used to store liquid and whose outer wall constitutes an external e...

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Problems solved by technology

[0004] However, the slight shaking of the liquid stored in the main body of the container is also likely to cause the water surface to sway. Therefore, the capacitive water level detector in the prior art repeatedly detects the water level in a very short period of time, and the vibration phenomenon will inevitably occur.

[0005] Therefore, the capacitive water level detectors in the prior art cause erroneous operation due to unnecessary frequent detection actions and vibration phenomena, shortening the life of components, thereby reducing reliability and durability

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