Abstract: The present invention relates to a system for measuring a capacitor (C). A current source (12) is connected in parallel to the capacitor (C) between a supply plane (Vc) and ground (VGND) for providing a current to the capacitor (C). A voltage level-shift is connected between the supply plane (Vc) and the ground (VGND) in parallel to the capacitor (C) and in parallel to the current source (I2). The voltage level-shift senses a voltage across the electronic component (C) and provides a level-shifted output voltage Vout in dependence thereupon. The voltage level-shift comprises a resistor (RI) connected in series with a current source (II) and an output port interposed between the resistor (RI) and the current source (II). The current sources (I,) and (12) have opposite temperature coefficients such that the current provided to the electronic component is substantially constant.

Abstract: The present invention provides an electromagnetic telemetry apparatus and methods that include an insulating connector that comprises an outer metallic female member that has an inner conical longitudinal surface. In one embodiment, a tubular metallic male member is disposed in the female member, thereby crating an axial conical gap between the male and female members. A conical metallic sleeve having dimensions that substantially correspond to the axial conical gap is disposed in the axial conical gap. The outer tubular surface of the male member is coated with an insulating material, such as a ceramic material. A shoulder at one end of the male member prevents axial movement of the sleeve in one direction and a parallel key between the female member and a stabilizer member prevents rotational movement between the male and female members. The sleeve remains stationary relative to the insulated surface of the male member when the male and female members move longitudinally relative to each other.

Abstract: The present invention relates to a system for measuring a capacitor (C). A current source (12) is connected in parallel to the capacitor (C) between a supply plane (Vc) and ground (VGND) for providing a current to the capacitor (C). A voltage level-shift is connected between the supply plane (Vc) and the ground (VGND) in parallel to the capacitor (C) and in parallel to the current source (I2). The voltage level-shift senses a voltage across the electronic component (C) and provides a level-shifted output voltage Vout in dependence thereupon. The voltage level-shift comprises a resistor (RI) connected in series with a current source (II) and an output port interposed between the resistor (RI) and the current source (I,). The current sources (I,) and (12) have opposite temperature coefficients such that the current provided to the electronic component is substantially constant.