TX Series High Voltage Triggered Spark Gaps Deliver:

• The ability to withstand extreme field conditions required by commercial, industrial and military needs
• High reliability energy transfer switching applications
• A wide range of voltages in a rugged miniature ceramic-metal package

The TX Series is a miniature ceramic to metal three-electrode triggered spark gap that provides low susceptibility to nuclear radiation for use in advanced military ordnance applications with short delay time and low jitter characteristics. A key design parameter of these gaps is the inclusion of radial tabs that are integral with each electrode and this configuration provides convenience of mounting and insures a low intrinsic level of self-inductance and low circuit resistance. In addition, these components have been tested and certified to meet rugged levels of environmental requirements and reliability in performance. All together, these features make the TX Series well suited for electrical energy transfer applications, such as weapon detonation by use of electro-explosive devices or timing of missile stage separation during space travel, where precision timing is required. The need for reliable switching is commonplace in existing military equipment and will be required for new programs of advanced missile and nuclear weapon technology that are now in the planning phase.

These switches have been applied to a wide range of other types of applications in military, commercial and industrial equipment. The suitability of these gaps is based upon unique gas discharge characteristics not found in competitive solid state products. These characteristics include low component inductance and capacitance, ability to handle high currents at high voltages and result in near infinite resistance during standby conditions. Their size permits small modules to be manufactured containing the energy storage capacitor, gas tube switch and the trigger transformer. Additionally, the high reliability of these gaps for environmental and electrical performance is based on consistently meeting the defined product specifications without degradation.

Other uses for these gaps include pulse generation and ultra-fast switching for protection requirements against damage to critical circuit components such as power tubes and power transformers commonly occurring in commercial and military radar and communication transmitters.

Power transformers that are utilized in security systems are vulnerable to transient voltages caused by power surges, lightning strikes, or switching of inductive loads. When short circuit currents flow in the transformer, the windings may be damaged by excessive currents. The TX triggered gap is used to isolate the transformer from the input circuit and prevent circuit failure.

Power tube protection is needed to extend the useful life of the expensive high voltage transmitting tubes. Screen grids which are often constructed with thin wires are vulnerable to burn out during operation due to high voltage arcs. These triggered spark gaps are used to provide crowbar action to prevent a meltdown condition and end of life for the power tube. Use of these gaps has proven to be extremely advantageous in protecting dc circuit components against input line voltage transients and short circuit load conditions.

Typical applications by market include:

Military 

• Exploding bridge wires (EBW)
• Exploding foil initiators (EFI)
• Slapper detonators (SD)
• Electronic safe and arm (ESA)
• Missile stage separation

Commercial/Industrial

• Crowbar circuits
• High current surge generator
• Medical lithotripsy
• High voltage switches for laser firing
• High d_i/d_t switching

Figure 1: Test Circuit for TX Triggered Spark Gaps

The circuit shown in Figure 1 is commonly used for testing the triggered spark gap characteristics. The triggered gaps may be used to switch either low or high level pulses that may range from nanoseconds to milliseconds in duration. The useful life of these products is rated in coulombs of charge that are passed through the gap, with the longer duration pulses resulting in shorter life rating.

The TX Series has been designed to meet stringent application requirements and has been tested and certified for mechanical, environmental, and electrical specifications by an independent EIA accredited test laboratory. To insure the reliability of these gaps all electrical tests were performed over the temperature range of -55oC to +100oC. Certification tests were conducted according to the test methods for electronic and electrical components as prescribed in Mil-Std-202. After exposure of samples to shock, vibration and altitude tests, each unit was tested to a series of electrical tests including delay time, trigger breakdown, peak discharge current and standoff voltage. The reliability of performance was verified by the tight distributions of test results.

TX Series spark gaps, with main static breakdown voltages of 1,000 to 10,000 Vdc and various footprints, including a surface mount design, are now available at a relative low cost in volume production quantities. Standard lead times are 6 – 8 weeks ARO. Contact us for additional information.