Fault Detection System For Cell Phone Motor

The cell phone is popular more and more due to the development of economic and technology, there is a vibration motor in every cell phone, it greatly impulse the requirement for cell phone motor. The output of cell phone motor in China is 80% of the output of whole world or more. The rotor touch the outer case in assembling process is a tough fault, it always bring on huge scrap, more worse is that there is no effective method to inspect this fault, in general them rely on the ear test by workers, the judgment is not always reliable, so, to raise a advance method is value-full for this industry.This paper describes a low cost, portable instrument for Cell phone motor fault detection. The hardware of this system is based on S3C44B0X, adopt accelerate sensor MMA7260 for vibration signal collecting, and USB interface chip PDIUSBD12 for data transfer, and then transplant U-boot and uClinux, lastly, the driver of the accelerate sensor and signal colleting program will be downloaded to the system. For the Vibration signal, some of impulse caused by impact can be occasionally found on the normal sinusoidal Vibration signal, the purpose of signal processing is to highlight the character of this fault signal. The recently developed wavelet based analysis becomes an efficient alternative in dealing with non-stationary type of machinery transient signal. The ability to detect transient in vibration signal makes it to be a powerful tool of detection of fault.This paper describes the design process of this detection system, and then fabricated a demo board for experiment. Experiment show it can meet the design-spec. This design is a good reference for the development of this kind of commerce instrument.