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Automotive Circuit Protection Using High-Reliability TVS Diodes

Diode technology eliminates transient surges and enhances vehicle safety. Littelfuse, Chicago, Illinois Designing automotive electronics presents numerous technical challenges, including the need to protect against electrical hazards. The three major sources of electrical hazards in automotive systems are electrostatic discharge (ESD), switching loads in power electronics circuits, and lightning. Overcoming these transient surges that can harm the vehicle’s electronics, whether under the hood or in the cabin, is one of the biggest obstacles of system design.

Posted in: Briefs, Power Management

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A Resistive, High-Voltage, Differential Input Interface in a 3.3-V BiCMOS 0.5-μm Process for Extreme Environments

NASA’s Jet Propulsion Laboratory, Pasadena, California Wide-temperature and extreme-environment electronics are crucial to future missions. These missions will not have the weight and power budget for heavy harnesses and large, inefficient warm boxes. In addition, extreme-environment electronics, by their inherent nature, allow operation next to sensors in the ambient environment, reducing noise and improving precision over the warm-box-based systems employed today.

Posted in: Briefs, TSP, Power Management, Sensors

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Precision Current Input With Well-Defined Current Limiting for Extreme Environment Applications

NASA’s Jet Propulsion Laboratory, Pasadena, California Wide temperature and extreme environment electronics are crucial to future missions. These missions will not have the weight and power budget for heavy harnesses and large, inefficient warm boxes. In addition, extreme environment electronics, by their inherent nature, allow operation next to sensors in the ambient environment, reducing noise and improving precision over the warm-box-based systems employed today.

Posted in: Briefs, TSP, Power Management, Sensors

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PATTERNS: Panoptic Aspect Time Triggered Ethernet Robust Network Scheduler, Version 1.0

Lyndon B. Johnson Space Center, Houston, Texas The PATTERNS scheduling tool was created to test the multi-plane concept of a Time Triggered Ethernet (TTE) network. The TTE network interface cards used in the Orion vehicle contain three physical network ports, referred to as planes. Each plane exists to serve as a redundant communication channel for each link in the network. The scheduler used prior to PATTERNS was the vendorprovided demonstration tool, TTE-demo-scheduler, which was unable to schedule Ethernet traffic in a manner that would allow the plane-specific and plane-independent tests required to be performed.

Posted in: Articles, Briefs, TSP

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Electromagnetic Waves Transformed from a Coherent to a Quasi-Coherent Nature

NASA’s Jet Propulsion Laboratory, Pasadena, California The transformation of naturally occurring electromagnetic waves called “chorus” from a coherent nature to a quasi-coherent nature when propagating a distance from its source was demonstrated. The aim of the mission was to study the energizing of electrons by the waves and also the loss of these particles by interaction with the waves. Both of these processes will be affected by the quasi-coherent nature of chorus. This work indicates that if coherent waves are not propagated in enhanced ionization ducting, the waves will become only quasi-coherent, and their effect of scattering trapped particles will be substantially diminished.

Posted in: Articles, Briefs

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An Earth-Observing, Frequency-Agile Radar Receiver for RFI Mitigation

Applications include automotive collision-avoidance radar, cellular phone networks, and radar surveillance sensors for unmanned vehicles. NASA’s Jet Propulsion Laboratory, Pasadena, California The Soil Moisture Active Passive (SMAP) mission will have the first L-band radar/radiometer sensor suite dedicated to global measurements of soil moisture. For the radar sensor, the requirements for achieving high backscatter measurement accuracy from low-Earth orbit present a unique design challenge in the presence of terrestrial radio frequency interference (RFI). The SMAP radar shares the same 1,215 to 1,300 MHz spectrum used by high-power ground-based transmitters like air-route and defense surveillance radars, which can generate strong interference in a conventional fixed-frequency spaceborne radar. The noisy ground environment motivated the development of a frequency-hopping (self-tuning) feature in the radar design. As the SMAP spacecraft orbits across various regions of the Earth, the radar continually adjusts its RF operating frequency to quieter areas of the spectrum for improved fidelity in soil-moisture science data observations.

Posted in: Articles, Briefs, TSP

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Wireless Electrical Devices Using Floating Electrodes

Langley Research Center, Hampton, Virginia A wireless, connection-free, open circuit technology can be used for developing electrical devices like sensors that need no physical contact with the properties being measured. At the core of the technology is the SansEC (Sans Electrical Connections) circuit that is damage-resilient and environmentally friendly to manufacture and use.

Posted in: Articles, Briefs, TSP, Sensors

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