摘要：The motivation of this paper is to design and fabrication a cost effective magnetic levitation (shortly called Maglev) system using PLC. For this purpose a stand, a 12 volt electromagnet, eddy current displacement sensor which input voltage is 24 volt and output voltage range is 0 to 10 volt for 0 to 10 mm displacement, Siemens Logo PLC setup board including CPU, cable, analog expansion module, an amplifier circuit & Logo soft software are used. Sensor senses the displacement of a target and gives corresponding signal in terms of voltage. This sensor output voltage is used as input in PLC input terminal. CPU works according to ladder diagram which is installed in program memory. The electromagnet is connected to the analog expansion output terminal. The current is controlled by PLC according to sensor signal which passes through the electromagnet. When distance between the sensor and target is increased the output sensor voltage is increased. PLC receives this voltage and decrease the current supply at output terminal. Thus the magnetic force is decreased and target is levitated at a desired position. When the distance between the sensor and the object is decreased, then current is increased in electromagnet which increases the magnetic force and the target returns to its levitate position. Finally the target is levitated. This paper will be helpful to simplify this control system and implement in different types of maglev study and industrial issues as well.
