Capacitive sensor and method and apparatus for controlling a pump using same

A pump control for controlling a level of a liquid in a reservoir, the pump controller comprising:

• a pump for being selectively activated to move the liquid out of the reservoir;
• a power supply electrically connected to the pump for providing an alternating current to the pump when activated;
• a sensor disposed at least partially within the reservoir for detecting the level of the liquid in the reservoir;
• and
• a controller electrically connected to the sensor and between the pump and power supply, the controller obtaining the detected liquid level from the sensor when the alternating current of the power supply is at a zero-crossing to determine if the pump should be activated.

A pump control for controlling a liquid level in a reservoir, comprising:

• a pump;
• a controller electrically connected to the pump for activating and deactivating the pump;
• a capacitor for providing a first capacitance to the controller for activating the pump and a second capacitance to the controller for deactivating the pump;
• and
• wherein the controller determines a run-time based on when the second capacitance was detected relative to when the first capacitance was detected, the run-time being an amount of time the pump should be activated to move a predetermined amount of the liquid out of the reservoir.