Capacitance sensing for component positioning detection

A linear volume shuttle pump, comprising:

• a first terminal and a second terminal movable with respect to one another, wherein the first terminal is a part of a pump mechanism;
• a sensor device operable to detect a change in capacitance between the first and second terminals as the first and second terminals move with respect to one another, wherein the sensor device comprises:
• a two-stage charger connected with a controller and a voltage source, the two-stage charger comprising a first capacitor connected with a first switch and a second capacitor connected with a second switch, wherein the controller is operable to:
• close the first switch to connect the first capacitor with the voltage source to charge the first capacitor;
• and
• open the first switch and close the second switch to connect the second capacitor with the voltage source to charge the second capacitor.

A method, comprising:

• positioning a first terminal adjacent a second terminal, wherein the first terminal and the second terminal are movable with respect to one another;
• detecting a change in capacitance between the first terminal and the second terminal using a sensor device, wherein the sensor device comprises a two-stage charger connected with a controller and a voltage source;
• charging, by the controller, a first capacitor by closing a first switch to connect the first capacitor with the voltage source;
• and
• charging, by the controller, a second capacitor by opening the first switch and closing a second switch to connect the second capacitor with the voltage source.