Research Of Precise Elec. Power For Laser Test

In 21Th the knowledge-based economy of century predominate position. Tostrongly develop high new technique is the inevitable choice to greet the arrival ofknowledge-based economy. The laser and light electrical technical is the most importanttechnical which develops the most quickly and be used the most widely today and will bethe main business in 21Th.In a lot of the process of applying lights to control actuallyproduce process, maintaining the light strength is very important.The stable laser in power source is applied widely in precise light electricityexamine and light electricity corresponding. This design introduced a kind of systemaccording to the system on the chip adopting the PID regulate to control the laser tubeoutputs to make the power stable in laser output.System on the Chip :Because of its super-speed degree, high gathered, high steady,high price ratio it is favored by the customer more and more. Here we adopted the sliceof C8052F020 Chip of the Cygnall company of the United States. It counts the Watchdog, A/ D, D/ A, numerous resource of the machine, the etc. and PWM is gathered inwhole body. In addition it has 51 core inside so it is easy to market and suffer theapprobation of numerous factories. Here the resources that I primarily use is A/ D, D/ A.They distinguish to 12 bit. It is complete to satisfy the engineering the inside<0.1%request.The voltage of the laser light source to drive the electric is carried out from theC8051F020 D/ A. The light source gives out light, the laser produces the electric currentafter receiving the light signal in tube ( PD) till. And then convent the electric current tothe electric voltage, give the electric voltage signal to the C8051F020 A/D for the moldnumber conversion., then give back D/A the signal again after calculating. So itcompletes the wreath control which feedback the importation to the exportation. Thissystem designs the LD driving electric circuit, and its driving electricity is variable from0 to 100 mA ,minimum adjustable measure<0.1 mA. The MCU adopts PID to regulatethe electricity current deviation to control the system. That make the laser diodeoutputting electric current stability.This system is a test&control system based on the RS232 serial communication. Weuse Delphi to make the application program. In Delphi, we install the activex controlcomponent(MSCOMM) of VB, and then, we can enable PC and MCU communicationeach other. We also have designed the protection circuit for the system witch make thesystem more stability.This system has already been produced and also been tested. It works steadily, meeteach technology requirement. This system is also a system that is maintained easily, usedsimply, and works steadily.