Digital Discharge Protect System For High Power Axial-flow CO₂ Lasers

The development of digital technology enabled multiple protection functions to be integrated into a compact protection platform, which owns over 30-year experience in practice. Digital Multifunction Protection Systems (DMPS) based on microprocessor, are first taken in practice in generators. The advantages of DMPS make more and more engineers take consideration into replacing the single function static and electromechanical relays by DMPS.An application of DMPS in high power fast-axial-flow CO2 lasers is introduced in this paper. The characteristics of gas discharge lead to some markedly differences in structure between DMPS for CO2 lasers and that for generator. By monitoring voltage, current as well as feedback optical power, the DMPS for CO2 laser provider a serial protect functions. Those functions include Imbalance, Over/Under-Voltage, Latch and HighLane-Restriction etc. Furthermore, in order to confirm the systems operate under a correct status some contact signals from center control platform, such as PULSE-MODE, are connected to the protect systems. The reliability of DMPS we introduced is approbated, and they are applied in high power industrial CO2 lasers.Additionally, we make some improvements to better efficient and reduce cost. Three types Analog-Digital Converters (ADC) are taken into account to replace some significant analog circuits. The work of circuit designing will be benefited because all these ADCs own compatible interfaces with microprocessors and capability of serial output. In plus, two of ADCs own multi-channel analog inputs. The most crucial two parameters, pre-channel sample rate of ADC and process delay of CPLD, are carefully calculated. They should meet necessary requirements otherwise DMPS will be invalid. The Verilog HDL codes together with simulating waveforms respectively are given.