A simple pulsed Nd:YAG laser power supply adopted ZCC method

The pulsed Nd:YAG laser is the most commonly used type of solid-state laser in many fields. In material processing and medical treatment, the power density control of a laser beam considered to be significant, which depends on the flashlamp current pulse width and pulse repetition rate. For general laser power supply to control the laser power density, the secondary of the power transformer is connected to the rectifier and filter capacitor. The output of a rectifier is applied to a switching element in the secondary of the transformer. So power supply is complicated and the loss of switching is considerable. In addition, according to increasing pulse repetition rate, charged energy of the energy-storage capacitor bank is not transferred sufficiently to a flashlamp, and laser output efficiency decreases. In this study, we have proposed a power supply in which the SCR was turned on at the zero point of input AC voltage by the method of zero crossing control (ZCC). As a result of that, the new power supply employed ZCC are simple and compact in design. Laser output efficiency increased by 3.5% other than conventional power supply (SCADC), when a repetition rate was increased by 10 pps. For 60 pps, efficiency was increased by about 20%.