High-Precision Switched Capacitor Device with an Energy Estimation Circuit

Abstract

This article introduces a device for the precise testing of the non-linearities of inductive voltage dividers and digitizers used in digital impedance bridges. The device is based on switched capacitors composed of an NP0 dielectric, in addition to high-quality microwave relays. The article discusses issue concerning the symmetrization of the device as one of the main ways to achieve a high accuracy. Furthermore, a temperature-stabilization system for the device is presented. The system uses a battery management system to estimate the quantity of the energy available in the supply battery. The article further discusses problems encountered with the design of heating elements, which are situated on a laminate with an aluminum substrate.

Keywords

• inductive voltage divider
• impedance comparison
• switched capacitors
• permutation method
• digitizer
• energy estimation