SIG Series

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HED Introduces Breakthrough SIG Series


10 mil operation

SIG Series High Voltage Gas Discharge Switch Provides:

  • Vast increase in operating life for pulse mode energy transfer applications at temperature extremes
  • Is immune to the failure mode
  • Sets high standard for reliability of switching in the pulse mode

Development of a new high performance gas discharge switch (spark gap) at High Energy Devices, LLC makes possible the next generation of product applications and sets higher standards of operating life that will minimize the high cost of equipment repair. The Spark Igniter Gap (SIG) Series is a hermetically sealed two electrode gas discharge switch that offers extended life operations and a constant breakdown voltage. The product’s specifications are demonstrated at extreme temperature conditions of -65oC to +125oC while maintaining an insulation resistance level greater than 1010 ohms.

Despite the dominant trend in circuit technology toward micro miniaturization, many electronic requirements are continually increasing the need for energy transfer devices in the hundred and thousand volt range. The application of the gas discharge switch has long been the ideal component because of its characteristic of switching from the insulating to the conducting mode in an extremely short time interval. However historically, customers have been conditioned to expect limited life and rapid wear-out of the switch and the need for frequent replacement. The SIG Series, now offered by HED, has resulted in a vast increase in operating life without insulation resistance problems. These devices make possible energy transfer applications having greater serviceability with reduced cost of equipment maintenance. Typical applications would include igniters for furnace ignition, high intensity discharge lamps, and military and commercial aircraft engines in addition to medical lithotripters for non-invasive surgery and high voltage switches for laser firing.

HED invested heavily in searching for improved electrode materials used in standard commercial products, which would overcome problems of limited operating life and rapid erosion. The goal was to use elements that would provide durability, meet high performance standards and still be cost effective to satisfy a broad scope of military and commercial products. The end result was the development of the SIG Series spark gap.

Life tests of the SIG3.0 (spark gap with dc breakdown of 3.0kVdc) have been conducted to establish the cumulative charge transfer and insulation resistance ratings of the switch. After months of continuous operation and occurrence of 10 million shots, there is essentially no change in dc breakdown voltage. Furthermore, the insulation resistance level remains above 1010 ohms and life testing at extreme temperatures, –65oC and +125oC, has negligible affect on the dc breakdown.

To confirm our findings and determine comparative performance of the SIG Series with the most durable Legacy electrode material, HED conducted life tests on sample spark gaps made with Tungsten (with the highest melting point of all metals at 3410oC) electrodes, and processed them the same as the SIG Series. The results of these tests are shown in Figure 1.

sig graph

All spark gaps have been operated at energy levels of 3.6 Joules at 3 pps under 1/3 on/off cycle conditions.

1. The SIG Series Spark Gap was operated for 10 million shots with a total charge transfer of 24,000 coulombs. The breakdown voltage remained relatively constant at 3000V and the insulation resistance measured greater than 1000 MΩ.
2. The Traditional Spark Gap (using the SIG Series configuration and pure Tungsten electrodes) was removed from test after operation of three (3) million shots with a total charge transfer of 7,200 coulombs due to rapid drop in DC breakdown voltage and IR levels less than 1000 MΩ.

The SIG Series represents a significant advance in the manufacturing technology of high voltage gas discharge switches. The operating life of the SIG Spark Gap has been shown to be increased over 300% compared with that of Tungsten while still maintaining a constant breakdown voltage and an insulation resistance level greater than 1010 ohms. The high cost to conduct frequent inspection of ignition operating systems and routine parts replacement can now be greatly reduced.

These gaps are available for shipment now. Call us or click here for additional information.

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