ABSTRACT
Along with the rapidly development of science and technical, the test and control technique of non-physical quantity, have already been applied in the field of aerospace, aviation, transportation, metallurgy, machine facture more and broadly, petrochemical, light industry, technique supervision and test, etc. as well, and also gradually leading to people's daily life. It can be said that, the level of technique test and automatically control, is an important symbol that to judge the modernization of a country’s science and technique.
The title of this thesis is Tachometer Design based on Photoelectric Detection Technology, mainly use the CPU AT89S52 DC Motor real-time Speed-measuring system. The tachometer is based on photoelectric sensor, after data are analyzed and treated by interior programming calculation; it gives analog quantity output and series entrance CY output according to actual requirements. Its real-time speed values are directly displayed by LED. It also has the functions of over-speed alarm and series communication entrance, realizing measure of low - high speed values; it has advantages of the simple hardware structure, fast speed measuring, high accuracy and reliable operation.