Liquid level detecting circuit, controller and water heater

Abstract

The invention applies to automatic control over air conditioners and provides a liquid level detection circuit used for detecting the liquid level in a liquid container and outputting detected liquid level signals to a corresponding control device for controlling water pouring or discharging. The liquid level detection circuit comprises a detection electrode and a signal processing circuit. The detection electrode comprises a common terminal arranged on the bottom of the liquid container and a plurality of detection terminals arranged from the bottom to the top of the liquid container, and safe ultra-low alternating current voltage is connected into the common terminal. The signal processing circuit is connected with the detection terminals and comprises a plurality of output terminals corresponding to the detection terminals, and the signal processing circuit is used for outputting detection waveforms serving as liquid level signals at the corresponding output terminal after receiving the information that detection signals are available at the corresponding detection terminal. Due to the fact that the safe ultra-low alternating current voltage is connected into the detection electrode, the detection electrode is not prone to electrolysis, corrosion and scales, and liquid level error judgment and control failures caused by influences of impurities in a water tank can be avoided.

Description

technical field [0001] The invention belongs to the field of liquid level control, and in particular relates to a liquid level detection circuit, a controller and a controller. Background technique [0002] At present, most ordinary water level controllers collect large DC or AC detection waveforms. When the liquid is not very pure, the electrodes of this controller are easily affected by electrolysis, corrosion, scaling, etc., which greatly shortens the service life of the electrodes. It will also cause misjudgment and failure of liquid level control. Contents of the invention [0003] The purpose of the present invention is to provide a liquid level detection circuit, aiming at solving the problem that the traditional liquid level detection electrode is easy to be electrolyzed, corroded, and scaled, thus causing misjudgment of the liquid level and resulting in control failure. [0004] The embodiment of the present invention is a circuit implemented in this way, which i...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a liquid level detection circuit, which aims to solve the problem that the traditional liquid level detection electrodes are prone to electrolysis, corrosion, and scaling, which cause misjudgment of liquid level and lead to control failure.

Images