Research On Driving Current Source For GMA System Based On PSoC3

GMM is a new functional material. It will be lengthened along the magnetic field. Coupling withthe high permeability material and the GMM as the core, and the drive magnetic field can make aGMA (Giant Magnetostrictive Actuator). The GMA has a fast response, considerable output force,high electromechanical coupling coefficient. Based on the properties of the GMM materials, thispaper designed a simple magnetostrictive actuator. Then according to the drive requirements of theGMA, design the driving DC current source and driving AC constant current source. Finally, based onthe simple GMA and the driving current source, test the properties of the GMM.Firstly, the paper designed a simple magnetostrictive actuator, including the part of the drive coildesign, magnetic circuit design and thermal design. Select a high magnetic permeability material asthe subsidiaries structure of the GMA. Then describe the main features of the PSoC3and selectedPSoC3as the main control chip.Secondly, according to the drive requirements of the GMA designed the DC current source basedon the Buck synchronous rectifier main circuit. Select the IR2110as the driver chip. The drivingmode is adaptive delay drive. Gathering the voltage across the freewheeling tube, when thefreewheeling tube body diode is turned on, the driving signal will drive the freewheeling tube turn on,minimizes body diode conduction time to reduce losses. The accuracy of the DC constant currentsource can up to1%. And the response time is2ms.Again, according to the GMA drive requirements designed the AC constant current source based onoctave SPWM modulation for full-bridge inverter. Select TLP250as driver chip and drive powerswitchers. Then according to the requirements of the driver, the inverter output current must beregulated the frequency, amplitude values as well as the DC bias. And in the case of DC bias, only onesingle driving coil can be used to measured through known designed AC constant current sourcefrequency can be adjusted between20~200Hz. The THD is less than five percent.Finally, driving the GMA and analyze the conducted under a variety of driving conditions. We canget the output displacement of the GMA with the variety of drive current. Compared the displacementbetween AC constant current source with DC bias and AC constant current without DC bias. Themaximum output displacement will decreases with the increasing frequency of the driving currentsource.