Delay characteristics of triggered vacuum switch and air spark gap for pulsed power applications

The closing switch is the main device to control the power supply of an ElectroMagnetic Launcher (EML) system. Five types of closing switches which included two triggered vacuum switches (TVSs), named TVS-1 and TVS-2, and three air spark gaps (ASGs) named ASG-1 , ASG-2 and ASG-3 with different configurations in a trigger unit are described for investigating the delay characteristics, high current capacity and erosion characteristics. An LC resonant circuit was set up and connected with the TVS´s and ASG´s main electrodes. A design circuit for controlling the TVS and ASGs is proposed. The trigger energy of the controller can be adjusted conveniently. By means of changing the trigger energy, the experimental data show that the delay time and jitter time decrease with increasing the trigger energy. The delay time and jitter time decrease magnificently with increasing the voltage in main gap. The improvement in the structure and controller of the TVS and ASG is a good way of decreasing the delay time and jitter time. It shows that TVS-2 has better performance in delay time and jitter time than TVS-1. Generally, ASG-2 and ASG-3 have shorter delay time than TVS-1 and TVS-2, as the initial plasma would be generated much more easily and quickly in the air than that in the vacuum case. The ASG has a shorter delay time and lower needed minimum breakdown voltage than the TVS. With a trigger energy of 0.064J, it is possible to fire the TVS and ASGs. The results show that the TVS is a better choice than the ASG with insignificant erosion.