Non-contact type capacitance induction level sensor

A liquid level sensor and capacitive sensing technology, applied in the field of liquid level sensors, can solve problems such as short service life, failure of water level detection, and easy to be damaged by lightning strikes, so as to reduce the probability of failure and prolong the service life

Inactive Publication Date: 2009-05-13
俞险峰
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] The traditional capacitive water level sensor has electrodes exposed in the water, and water acts as a medium to change the capacitance between the electrodes, thereby detecting changes in the water level; the traditional water resistance water level sensor has multiple electrodes, but when the water passes through the electrodes, the gap between the electrodes A weak current flows to detect changes in the water level; if the above two sensors are used in water with high temperature and poor water quality, it is easier to scale and cover the electrodes, resulting in detection failure
For example, the water level sensor in a solar water heater often has a short service life due to the above reasons, and in the thunderstorm season i

Method used

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  • Non-contact type capacitance induction level sensor
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Examples

Experimental program
Comparison scheme
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Example Embodiment

[0017] Example 1:

[0018] Refer to figure 1 , A non-contact capacitive sensing liquid level sensor, comprising an insulating housing 1, a capacitive sensing metal piece 2, a liquid level detection circuit 3, and an external signal interface 4. The insulating housing is arranged vertically, and the capacitive sensing metal piece is vertically arranged. Is arranged in a housing, the liquid level detection circuit is installed in the housing, and the liquid level detection circuit includes: an analog input port for connecting with the capacitive sensing metal part; for detecting the capacitance value of the analog input port, and The liquid level measurement module for obtaining the current liquid level value according to the preset correspondence relationship between the capacitance value and the liquid level, and the capacitance sensing metal piece is connected to the analog input port.

[0019] The capacitive sensing metal part is copper clad 2, and no less than two copper clads...

Example Embodiment

[0023] Example 2:

[0024] Refer to figure 2 The capacitive sensing metal part of this embodiment is a metal detection strip 22.

[0025] Liquid submerges the insulating shell, and the difference in the area covered by the metal detection strip will cause the change of capacitance. The change value of the capacitance is detected by the liquid level detection circuit 3 to linearly reflect the height and range ratio of the liquid level, that is, the capacitance value and the liquid level. The corresponding relationship is linear.

[0026] The use process of this embodiment is the same as that of the first embodiment.

[0027] This embodiment is applied in an oil tank, and the oil level signal is linearly and continuously transmitted to the automobile control system through an external interface.

[0028] This embodiment can also be applied to a water tank in which the liquid level signal is linearly and continuously transmitted to an external display system through an external signa...

Example Embodiment

[0029] Embodiment three:

[0030] The capacitive sensing metal part of this embodiment is a sensing spring.

[0031] The liquid floods the insulating shell, causing the capacitance of the induction spring in the insulating shell to change. The liquid level detection circuit 3 detects the capacitance change value to reflect the liquid level status or range ratio of the detected point.

[0032] The use of the spring keeps the capacitive sensing metal parts in close contact with the inner wall of the insulating shell, improving the sensitivity of liquid level detection, and is especially suitable for insulating shells with larger diameters.

[0033] The use process of this embodiment is the same as that of the first embodiment.

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Abstract

A non-contact capacitance induction liquid level sensor comprises an insulation shell, a capacitance induction metal part and a liquid level detection circuit. The insulation shell is vertically arranged, the capacitance induction metal part is vertically arranged inside the shell, and the liquid level detection circuit is arranged inside the shell; the liquid level detection circuit comprises an analog input port which is used for being connected with the capacitance induction metal part, and a liquid level measurement module which is used for detecting a capacitance value of the analog input port, and obtaining a current liquid level value according to a corresponding relation between a preset capacitance value and the liquid level; and the capacitance induction metal part is connected with the analog input port. The invention provides the non-contact capacitance induction liquid level sensor which can be effectively used for a long time even under a harsh environment.

Description

(1) Technical field [0001] The invention belongs to a liquid level sensor. (2) Background technology [0002] The traditional capacitive water level sensor has electrodes exposed in the water, and water acts as a medium to change the capacitance between the electrodes, thereby detecting changes in the water level; the traditional water resistance water level sensor has multiple electrodes, but when the water passes through the electrodes, the gap between the electrodes A weak current flows to detect changes in the water level; if the above two sensors are used in water with high temperature and poor water quality, it is easier to scale and cover the electrodes, resulting in detection failure. For example, the water level sensor in a solar water heater often has a short service life due to the above reasons, and in the thunderstorm season in summer, it is often vulnerable to lightning damage to the entire circuit, which hinders the promotion of solar water heaters as an energ...

Claims

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Application Information

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IPC IPC(8): G01F23/26
Inventor 俞险峰
Owner 俞险峰
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