Patent ID: 8330603
Filing Date: 2012-12-11
Classification: G01F

Abstract:
1. A water pump control circuit comprising: one or more sensors configured to generate respective sensing signals to indicate types of substance in contact with the respective sensors; a sensing circuit configured to receive the sensing signals and to generate a detection signal to indicate when any of the sensors is in contact with water, wherein the sensing circuit is selectively disconnected from at least one of the sensors during calibration of the sensing circuit; a controller circuit configured to receive the detection signal and to generate a control signal to activate a water pump for at least a programmable duration while any of the sensors is in contact with water, wherein the controller circuit intermittently enables calibration of the sensing circuit and updates the programmable duration based on user input; and a reed relay coupled between one of the sensors and the sensing circuit, wherein the controller circuit controls the reed relay to disconnect that sensor from the sensing circuit during calibration of the sensing circuit.