Study Of The Key Technology In Alternat Low Voltage Standard Source

In the process of satellite ground detection and telemetry, a lot of parameters are measured by low-voltage measurement. So low-voltage measurement is a important segment in satellite testing. There are many instruments in the spaceflight system which should be calibrated every year. The key technology of AC low-voltage signal measurement is studied in this article.Because the specifications of this subject are very rigorous, the main problem is how to release the noise and to improve the precision .The direct low voltage signal is a weak signal. Weak signal not only means low amplitude, but mainly means signals which are tangled by noises. This article studied the background noise such as low thermoelectric, resistance noise and 1/f noise to achieve the design requirements.In order to create accurate voltage signals in the AC low-voltage source, there must be an exacted norm source which can create 10V voltage signal. Both the effects of temperature and the changes of properties over time are considered in the article.In order to reduce and even eliminate noise voltage during the design of wave generator, I take the structural design of increased interpolation points offset M and harmonic filters. It is considered that the operational amplifier,resistorsand other devices will introduce noise.It will be specially considered in filter design to the following : The lower resistance resistor value; improve rated power of the resistance; reduce the number of operational amplifier; use low-noise operational amplifier and low noise filter.Self-programmed induction voltage divider is for the need of low voltage output signal. So the resistance of which thermal noise voltage is less than 18 nV. Through rational design, induction divider ratio uncertainty reach 10 -6~10-7.All the researches of key technology guarantee exchange standard low voltage source gauge a higher resolution of 1nV than the existing one with a resolution of 10nV. The standard source of the low voltage, will establish unified standards of AC low voltage measurement in the realm of national defense. It will play a important part in scaling a quantitative guideline about the measurement value of the AC low voltage, and will be helpful to improve the quality of Chinese spacecrafts.