Synchronous triggering of multiple spark gap switches

Abstract

This paper presents Fiber optics based technique for synchronizing the operation of two or more spark gaps. The aim of this work is to configure a pulse power system where various gas filled spark gap switches can be synchronized for simultaneous operation or with a preset delay with accuracy better than 50ns to achieve higher pulse currents. Use of fiber optic allows the various high voltage circuits to be electrically isolated from each other and thus offering simplicity in trigger control. Power for trigger system can be derived from the electrical fields near the trigger, so all electrical cables to the trigger system are eliminated and replaced with a fiber cable that triggers the system. We have used commercially available fiber optical transmitter HFBR1404 and receiver HFBR 2402 to configure the optical interface. The delay between the transmitted pulses is generated electrically and thus can be precisely adjusted to attain desired value. A TTL high speed high current driver is used to generate an electrical pulse which is converted to optical trigger pulse by fiber optic transmitter. The leading edge of the pulse is used for timing reference and pulse width is not important. fiber optic receiver converts the optical signal back to electrical signal which is further used to trigger gas filled spark gap