Abstract
At present, in electrical measure, the voltage is a very important parameter. How to measure the analog signal voltage accurately, it is always one of contents which the electric instrument for research. So the appearance of intelligent milivoltmeter has the very important significance.
This system introduce the development situation of intelligent milivoltmeter firstly, it takes AT89S52 as CPU design the hardware electric circuit of the intelligent milivoltmeter, and the system software flow chart. This system analysis the anti-interference of this system and proposed some anti-interference measures. The design of hardware part of this system mainly includes: the design of the input channel, the design of the A/D switch and the design of the display circuit and so on.
This graduation design makes a digital milivoltmeter using AT89S52 signal-chip, the connection circuit is simple, tests conveniently, can realize the high precision measure.
Keywords: AT89S52, AD574A; The automatic transforms of measuring range; Milivoltmeter