High Resolution Current / Voltage Measuring Technique in Spacecraft

摘要

This paper describes a high-resolution current/voltage measuring technique suited to spacecraft power systems. With an 8-bit telemetry (TM) system, we get 40mV/count as resolution. This is very poor when the measured parameter varies widely up to a large magnitude, ultimately resulting in inaccurate or no information. An attempt has been made here to show that true 12 bit resolution can be obtained without having to use a 12 bit analog to digital converter (ADC), let alone the difficulties involved in realizing such a system. The idea explained here improves resolution from 40mV/count to 2.66mV/count without changing the existing 8-bit TM system to 10 bit or higher. Finally, an application of this technique is presented, which is a high-resolution current sensor suitable for space application. The P-spice simulation results and waveforms related to a breadboard version are also presented.