FAQ

Non-contact sensing of a nearby object’s linear or rotary position in an electrically and mechanically harsh environment is a common system requirement. There are several ways to meet this objective, including sensors based on the Hall effect, the magnetorestrictive effect, and magnetic coupling. One widely used approach is inductive proximity sensing, which is effective, accurate, […]

The first part of this article introduced the inductive proximity sensor. This second and final part looks at some more specifics of this sensor. Q: Are there different architectures and implementations? A: Yes, there are three basic types: 1) the magnetic elements alone are in the sensor. This separates the electronics from the sensing coils […]

Electromyography (EMG) is a medical procedure that evaluates the health conditions of muscles and nerve cells. These cells transmit electrical signals that cause muscles to contract or relax. EMG is used to read these signals and plot them as numbers or graphs. Typically, EMG is performed by doctors as one part of a diagnostic tool […]

The ultrasonic sensor (or transducer) works on the same principles as a radar system. An ultrasonic sensor can convert electrical energy into acoustic waves and vice versa. The acoustic wave signal is an ultrasonic wave traveling at a frequency above 18kHz. The famous HC SR04 ultrasonic sensor generates ultrasonic waves at 40kHz frequency. Typically, a […]

Light sensors or photosensors, which are designed to measure light intensity, are one of the most commonly used sensors in electronic applications. Light intensity is one of the seven base physical quantities. The measurement of light intensity is useful in many consumer, industrial, and security applications. What is a light sensor? A light sensor is […]

Light sensors are widely used in electronic applications. The most common one used is a photoresistor or light-dependent resistor. Despite a long response time, this sensor is inexpensive and useful in several applications. A photoresistor consists of a zigzag track of photo-sensitive semiconductors. It offers pure resistance although this is dependent on the ambient light. […]

A 4-20 mA current loop is a very common method to convey the sensor data acquired for analog sensor data transmission. Sensors or transducers are usually designed to measure a range of values of the measured parameter, known as the measurand. The measureand value must be converted to current within the measuring device so that […]

This FAQ series has gone to extremes and looked at “electronics that operate in extreme heat” (up to 800°C) and “electronics that operate in extreme cold” at cryogenic temperatures. This third and final FAQ will consider the various methods available to create artificial cryogenic environments. The temperature where refrigerated temperatures end and cryogenic temperatures begin […]

For applications driven by sensors more than high-speed data, the IEEE 802.3cg standard offers single-pair Ethernet connectivity with far lower cable costs and bulk. Part 1 looked at the context and standard which defines Single-Pair Ethernet and some of its variations, and how it fits into the IIoT application area. This part will look at […]

The first part of this FAQ series looked at “electronics that operate in extreme heat” (up to 800°C). This FAQ delves into the opposite end of the temperature spectrum and heads toward absolute zero. There are several existing cryogenic electronics applications, including superconducting quantum interference devices (SQUIDs) for measuring extremely subtle magnetic fields, microwave preamplification, […]

For applications driven by sensors more than high-speed data, the IEEE 802.3cg standard offers single-pair Ethernet connectivity with far lower cable costs and bulk. Ethernet has come a very long way in adoption and speed from its humble inception driven in the early years by a team led by Robert Metcalfe at the Xerox Palo […]

Extreme environments require electronic systems capable of surviving beyond the MIL-STD operating temperature range of -55°C to +125°C. This FAQ series will go to extremes and look at super hot electronics (up to 800°C) and cryogenic electronics. Part one of this series looks at electronics that operate in extreme heat. Part two will look at […]

There are times when budget-priced instrumentation, or rented/leased instruments, will handle the job while going easy on the wallet. Amanda Wilson Back in the 1980s, car makers typically used a light vehicle platform for more than eight years before they saw a need to design and develop a new one. This sort of extended product…

The interface electronics for the LVDT must excite the primary-side winding with a sine wave and then demodulate the two resultant secondary-side waveforms; modern ICs make this analog-signal process fairly straightforward. Part 1 of this FAQ looked at the basics of LVDT excitation, demodulation, and waveforms. This part looks at two standard ICs which implement […]

The interface electronics for the LVDT must excite the primary-side winding with a sine wave and then demodulate the two resultant secondary-side waveforms; modern ICs make this analog-signal process fairly straightforward. The first two parts of this LVDT article (see References) looked at the LVDT transducer itself, along with its attributes and history. This second […]

Inertial sensors are used to transduce inertial force into measurable electrical signals to measure acceleration, inclination, and vibration of an object. Micromachining technology has made it possible to produce MEMS (Micro Electromechanical System) inertial sensors using single-crystal silicon sensor elements. These micron-sized sensors meet all major system design drivers like low-cost, high performance, high precision, […]

Novice engineers usually don’t learn about this problem and its solution in school, but “practicing” ones learn about it soon enough! Problem: I need to determine the change in resistance of a low-resistance sensor located many meters away. My plan was simply to apply a known voltage across the thin-wire sensor leads and measure the […]

The linear variable differential transformer (LVDT) is a widely used, inherently rugged, linear-position sensor offering accurate and consistent performance over a wide span of distances. Part 1 of this FAQ looked at the basic operation of the LVDT. This part looks at some of its other performance attributes and characteristics. Q: What does an LVDT […]

The linear variable differential transformer (LVDT) is a widely used, inherently rugged, linear-position sensor offering accurate and consistent performance over a wide span of distances. Sensing of physical position is among the most commonly needed parameters in industrial, military/aerospace, robotics, scientific measurement, and control applications, and there are many sensors in use to accomplish this. […]

Solid-state devices that convert heat to energy have a reputation for being inefficient. New materials may eventually change the equation. Leland Teschler • Executive Editor Estimates are that 61% of the energy consumed in the U.S. is lost to heat. No wonder, then, that there is interest in finding ways to harvest some of these…

By Brian Dempsey, system design engineer, Texas Instruments The numbers are a wake-up call: According to the United Nations, the buildings and construction sector accounted for 36% of the world’s energy consumption in 2018, contributing to a worrisome carbon footprint. And those percentages continue to grow. As a result, the race is on. Industrial design […]

It pays to know how RF can potentially garble the reception of signals such as those for WiFi, Bluetooth, and radar sensors. We live in a world with an increasingly crowded radio frequency spectrum that is only likely to become more stuffed with RF signals. This is particularly true for the frequencies within the ISM…

The radar sitting in your car’s bumper isn’t the same as the units vectoring planes in for a landing. Here are the most important differences. Leland Teschler | Executive Editor The last time you found yourself on an airplane, it’s likely that air traffic controllers kept track of you via radar sets operating at about…

Cryogenic temperatures may seem only of limited interest, but they are actually critical in many instrumentation and other systems. Measuring these ultralow temperatures is both easy and difficult, depending on temperature, material, and mass. Temperature is the most commonly measured physical variable, whether it’s just to assess the local weather to manage the performance of […]

Experts say the improved energy efficiency brought by LEDs is only a prelude to what will be possible with laser-generating diodes. Leland Teschler | Executive Editor An interesting deal popped up on eBay recently for a replacement headlight assembly. The headlight goes on a BMW i8 coupe. You can get one – sent from Latvia…