Powering the Future of Directed Energy Weapons

Today’s high-power lasers operate in a range of tens of kilowatts, but evolving designs to use hundreds of kilowatts, or even megawatts, is the ultimate objective. To wield such intense power, directed energy weapons use continuous- or pulse-power systems along with sophisticated switching and power-conditioning technologies.

These power systems require high-voltage interconnect solutions to maximize output energy while minimizing the power impact on the host platform. High-voltage interconnect solutions are employed “outside the box” for the energy path connecting the prime power source and energy storage, but also for components that convert energy into the desired output.

When starting any high-voltage power project, it’s valuable for designers to view interconnects as part of the complete system. Specific interconnect products have been introduced and new technologies continue to be developed to handle the challenges of high-voltage electric power. DEW designers have more options than ever, yet the power-related issues remain the same:
 

• Managing Extreme Heat Loads
  Designs for directed energy weapons must dissipate massive amounts of thermal energy to keep the energy source at a safe and efficient operating temperature. Specialized liquid coolers and heat exchangers are employed to transfer heat for rejection outside the system. The interconnects within the system must be able to withstand internal temperatures up to 1200°F (649°C).
  
  When a relay is exposed to high temperatures, pick-up voltage (VPI) and coil resistance (RC) are affected. To ensure stability, designers must determine the steady-state characteristics for the temperature and voltage combination of a direct current (DC) relay’s operating conditions. This is also true for alternating current (AC) applications, although their VPI exhibits less variation over temperature as compared to DC relays.
  
  
• Preventing Partial Electrical Discharge
  It is easier to manage high power on the ground, but directed energy weapons systems must also function in the air. High voltage can ionize air, which can become conductive to produce a corona discharge. The corona effect causes electrical power losses through voids, cavities, and electrical treeing as insulation breaks down, resulting in electrical arcing.
  
  Using proper dielectrics/insulating materials is critical to avoiding corona discharges. Insulation using cross-linked polymers for high-voltage wiring, cables, harnesses, and assemblies is formulated to resist breakdown. This type of dielectric is especially critical in power control modules and power converters.
  
  
• Avoiding Arc Tracking Damage
  With high-voltage sources in directed energy weapon platforms, carbon tracks may form on the surface of polymeric insulators. These tracks cause the insulator to lose its dielectric properties and to become an electric conductor instead. Electrical arcing can then occur across the conductive path, resulting in power loss with a high probability of ignition. To avoid this problem, proper insulation materials must be used.
  
  
• Handling the Effects of Environment on Inception and Extinction Voltages
  Inception voltage is when the corona effect starts; extinction voltage is when it ends. Partial discharges can occur when two parts of a circuit that are not adequately isolated are subjected to high voltage differences. Consequently, electrical systems must be designed to provide adequate electric isolation levels within the operating environment.
  
  
• Negating Skin Effect
  When determining proper shielding and filtering for electromagnetic compatibility (EMC), designers must account for skin effect, which is the tendency of AC current to flow close to the surface of a conductor. Skin effect is the result of eddy currents induced by the changing magnetic fields of alternating current and is, therefore, a factor in nearly every AC design. Printed circuit board (PCB) traces and other aspects of AC power circuits can be designed to negate skin effect, but expert planning is required.
  
  
• Managing Size and Weight Constraints
  Components used in high-power electrical energy storage and management can be large and heavy. High-efficiency relays and contactors are available to handle higher voltage and amperage within a compact footprint to help reduce size, weight, and power (SWaP) requirements. Specially designed cables, terminations, and connectors are also available to minimize SWaP.
  
  
• Meeting Higher Demand for Reliability
  Directed energy weapons applications may require a significant number of open and close cycles. This extreme cycling puts additional wear on the contact surface of mechanical switches, which must be designed to handle the added stress. For electric switches, proper sizing is needed to handle the required voltage level because transistors are sensitive to overvoltage.
  

Today’s interconnect products for high-voltage applications benefit from the cross-discipline development of power management solutions for automotive, aerospace, defense, energy, and rail sectors. TE Connectivity (TE) offers a broad range of products for directed energy weapon applications, including the following high-voltage solutions:
 

• High-Voltage Relays, Contactors, and Switches
  Advanced, hermetically sealed relay, contactor, and switch designs provide an excellent size-to-power ratio and offer voltage ratings up to 70kV DC and current ratings up to 1,000 amps. Environmentally sealed insulation gaskets are critical for high-voltage applications to minimize intrusion of moisture and contaminants to prevent arcing across the insulator.
  
  
• High-Performance Power Feeders and Environmental Sealing Protection Products
  Cross-linked polymers in advanced heat-shrink tubing and cable accessories can endure repeated heating and cooling cycles while retaining their original size and protective properties.
  
  
• Terminals and Splices for High Temperatures
  Terminals, splices, and spare wire caps are designed to withstand operating environments up to 1200°F (649°C).
  
  
• Lighter-Weight and Smaller Components
  Advanced sealed terminals and splices are available that are 60% lighter than conventional copper terminals.
  
  
• MIL-SPEC DEUTSCH Connectors
  The well-known DEUTSCH connector product family includes contacts and connectors, including the MIL-DTL-38999 compliant DEUTSCH connector series. The dielectric withstanding voltage for environmentally sealed DEUTSCH DT connectors offers current leakage less than two milliamps at 1500 volts AC.
  

With the range of interconnect products available today for high-voltage applications—and new products being introduced regularly—designers of directed energy weapons can find reliable and readily available solutions to meet critical requirements. Defense designers who work with experts who can design, customize, manufacture, and implement high-voltage solutions all along the power path can accelerate development of their projects.

• Directed energy weapons rely on high-power lasers, particle beams, or high-power microwave technologies that require high-voltage solutions. 
• Designers of directed energy weapons must solve the challenges high voltages impose on electrical interconnects.
• Directed energy weapons use continuous- or pulse-power systems along with sophisticated switching and power-conditioning technologies to maximize output energy while minimizing the power impact on the host platform.
• The high-voltage electric power demands of directed energy weapons present design challenges from extreme heat loads to negating skin effect.
• Today’s interconnect products for high-voltage applications benefit from the cross-discipline development of power management solutions for automotive, aerospace, defense, energy, and rail sectors.
• TE Connectivity offers a broad range of products for directed energy weapons applications.