title: Magnetically and optoelectronically isolated trigger for pulse-power applications.
abstract: In this article the design of a magnetically and optically isolated trigger is discussed. Critical issues for trigger design are presented together with some experimental usages. In this trigger, an optical coupler is used to cut off the ground loop between the circuits of the preceding control system and the power supplies of the double functional device KT-5D (as a simple magnetic torus or a tokamak). A magnetic coupler is used to provide a pulse-power output for the silicon controlled rectifier. The output is a 230 mus transistor-transistor logic (TTL) with an amplitude of 3.0 V. The rising time and the trailing time are no more than 4.0 mus. The delay time between the input and the output of the trigger is 6.8+/-0.2 mus. A resistance-capacity branch is integrated into the trigger to provide an adjustable delay time of up to 72 ms. The zero quiescent dissipation character endows the trigger with a long lifetime of years dispensing with any charging or replacing batteries. It is observed that the trigger has a good stability even in a high electromagnetic circumstance (at the order of 1 T). Using it as a trigger for the silicon controlled rectifier, we realized the compatible operation of the steady state mode and the pulse mode in KT-5D.
authors.affiliation: CAS Key Laboratory of Plasma Physics, Modern Physics Department, School of Science, University of Science and Technology of China, 230026 Hefei, People's Republic of China. yuyi@mail.ustc.edu.cn
authors.forename: Yi
authors.initials: Y
authors.lastname: Yu
authors.forename: Yi-Zhi
authors.initials: YZ
authors.lastname: Wen
authors.forename: Chang-Xuan
authors.initials: CX
authors.lastname: Yu
authors.forename: Shu-De
authors.initials: SD
authors.lastname: Wan
authors.forename: Wan-Dong
authors.initials: WD
authors.lastname: Liu