LIQUID LEVEL SENSOR
Original Publication Date: 1993-Oct-01
Included in the Prior Art Database: 2002-Feb-18
The problem to be solved by the suggested design is to avoid any moving electrical connections which would be subject to wear. That may happen, e.g. with sliding contacts across a resistor. We use a capaci- tive coupling between the lixed permanent electrodes and a floating device. E.g. two concentric cylinders are arranged according to Figure 1.a. The outer cyl- inder is fixed and has the metalized inner surface split electrically in two halves, and the inner mova- ble floating cylinder has a fully metalized surface. Permanent immobile connections are attached to the outer cylinder parts. Between the cylinders is deposited an isolating dielectric material either on the internal surface of the external electrodes or on the surface of the inner cylinder. This creates two serially connected capacitors CI and C2 having a resulting capacitance C as depicted in Figure 1.b.