Design of a Digital Controller for an Ultragravimetric Microbalance

摘要

The design and construction of a digital control system for an Ultragravimetric pivotal beam microbalance has been performed. The digital system replaces the present analog control circuitry of the microbalance. Included in the design is a hardware circuit, a Z-151 computer which has been interfaced to the circuit, and software to control the circuit and to operate the microbalance. An analysis of the present analog control circuit is first presented. This analysis gives the overall function of the circuit as well as an indepth view of the configuration of a particular operational amplifier: the derivative compensator. The hardware for the digital control system is described followed by the development of the software which controls the system. Studies performed on the experimental design revealed that the system satisfactorily simulates the analog control circuit. Tests show that the system automatically zeros the balance, weighs the sample, stores the data onto a disk file, and terminates the experiment. (Theses)