Design And Implementation Of High And Low Voltage Isolation Locomotive Wireless Optical Transmission System

The Catenary-panto of the locomotive is a high voltage of 27.5kV,while the locomotive roof is of low terminal.When we need to transfer information between the two ends of them,it is imperative to maintain the two ends of the insulation performance.Radio waves can not meet this requirement,but the carrier wave of light for optical transmission methods could meet such a request.Because comparing with ordinary electromagnetic,optical frequency is very high,therefore it can avoid from electromagnetic interference.So it is an ideal method for transportation.Optical Communication also can provide much higher transmission speed and bandwidth than radio to meet the growing large amount of information transmission requirements.Optical Communication is divided into optical fiber communications and wireless communications. The greatest advantage is that Wireless Optical communications avoid laying fiber to facilities and simplified equipment.In practical application,We usually offer the Wireless Optical Fiber Communication to be a backup.Therefore,based on the above considerations,we designed the locomotive for high and low voltage of the transmission of information-optical transmission system.。This paper briefly introduces the classification of optical communication system,function block diagram of the system also is given. At the same time we introduced a wireless optical communication on the status and development prospects.Then briefly introduced the optical transmission system in the light source and an important component of the carrier wave modulation circuit.Focus on the optical transmitter for using in the electric field,including binary frequency shift keying, the frequency division multiplexing,width wave frequency modulation and square wave frequency modulation,the principle of their major applications and so on.In this paper we designed several functional modules,including audio signal amplification,shaping,V-f converters,frequency shift keying modulation;signal-level data conversion,amplification and frequency shift keying modulation;Image Signal filtering,amplification, as well as three-way signal multiplexing,and pulse frequency modulation, etc.Finally,using simulation tests,the results were satisfactory.