Development of 10 kV Pulsed Power Supply for 600 W V-Fold CW CO2 Laser

Commercially available 100 W CW CO2 lasers have limited life of 3-4 years. These lasers becomes non-functional due to deterioration of gas filled in these laser systems.  We have developed a technology to refill proper gas mixture in these laser systems.

Highlights:

• Power supply is based on two-switch forward convertor topology and consists of a single phase rectifier with filter, MOSFET-based two-switch forward converter and high frequency transformer. 

• Power supply includes short circuit and over current protections for its safe operation.  

• Power supply is housed in a 19 inch, 3U size sub-rack unit.  

• Pulse power supply has been successfully tested at its rated specifications using a dummy load. 

• Output Specifications:

Peak output voltage: 10 kVpk

Pulse width: 5 μsec

Pulse repetition rate: 5 kHz

• Basic aim of the experimental setup is to measure the photocurrent from a device under test (DUT) as a function of wavelength. 

• Automation is indispensable for the coordinated operation of various instruments, data collection and plotting. 

Highlight of the developed software:

Controls various functions of the following instruments which are interfaced to a PC:

• Zolix Omni-λ Series Monochromator: extracts desired wavelength spectrum (400 - 700 nm) from a broad band source. 

• Keithley Source Measurement Unit (Model 6430): measures photocurrent of DUT. 

• 6½-Digit Digital Multimeter, Keithley make (Model 2000): measures photocurrent from reference Silicon   photodiode 

• Microcontroller based Motorized shutter: used to keep DUT in dark for a defined period before measuring photocurrent for a new wavelength.

Publication: A. Verma et al., Proc. 3rd National Conf. Nanoscience & Instrumentation Technology, June 6-7, 2015, NIT, Kurukshetra. 

• Break down maintenance of the power supply of EXSPLA make Nd:YAG laser system
• The fault has been identified as a faulty IGBT in simmer power supply card of the laser.
• The fault has been rectified and the laser has been restored to its previous functioning capacity.