The Design Of The Electromagnetic Metal Detectors

Metal detectors, as the name implies, is used to test the existence of metal by using a certain equipment. Initial Mine detector evolved to now, metal detectors’influence has developing in all aspects. Such as airport security, protect products from stolen and the testing of metals in food.Firstly introduces the working principle of electromagnetic field and its influence on coil, explains three factors that have influence on swirl strength, the method of signal detection, the selection of the detection elements and induction characteristics of different kinds of metals in a magnetic field. Later discusses the factors that affect the sensitivity of the detectors.Secondly explains the main control components C8051F500and its communication characteristic. After this give a plan about how to design the hardware and all parts of the hardware. The whole circuit including a square wave signal generating circuit, a sinusoidal signal generating circuit, the power amplification circuit of the sinusoidal signal, the transformer and expansion flow circuit, the receiving signal amplifying circuit, the peak hold circuit, the signal conditioning circuit, RS485communication interface circuit and the CAN bus interface, etc..Thirdly explains the software design of the metal detector. Then introduces the development environment includes/u Vision2about it’s advantages of the environment, the steps to create a project and the simulation debug mode.Later introduces the main program flow chart.Digital filter algorithm, AD converter, RS485communication interface and CAN bus interface flowchart is also introduced.At last validates the metal detectors experimental system through simulation.We can see that this detector has a high precision and a stable performance through the simulation data.