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Back in September, within the introduction to my teardown of a pulse oximeter, I wrote:

One upside, for lack of a better word, to my health setback [editor note: a recent, and to the best of my knowledge first-time, COVID infection over the July 4th holidays] is that it finally prompted me to put into motion a longstanding plan to do a few pandemic-themed teardowns.

That pulse oximeter piece was the kickoff to the series; this one, a dissection of an infrared thermometer, is the second (and the wrap-up, unless I subsequently think of something else!). These devices gained pervasive use during the peak period of the COVID-19 pandemic, courtesy of their non-contact subject measurement capabilities. As Wikipedia puts it:

At times of epidemics of diseases causing fever…infrared thermometers have been used to check arriving travelers for fever without causing harmful transmissions among the tested. In 2020 when [the] COVID-19 pandemic hit the world, infrared thermometers were used to measure people’s temperature and deny them entry to potential transmission sites if they showed signs of fever. Public health authorities such as the FDA in United States published rules to assure accuracy and consistency among the infrared thermometers.

And how do they work? Wikipedia again, with an introductory summary:

An infrared thermometer is a thermometer which infers temperature from a portion of the thermal radiation sometimes called black-body radiation emitted by the object being measured. They are sometimes called laser thermometers as a laser is used to help aim the thermometer, or non-contact thermometers or temperature guns, to describe the device’s ability to measure temperature from a distance. By knowing the amount of infrared energy emitted by the object and its emissivity, the object’s temperature can often be determined within a certain range of its actual temperature. Infrared thermometers are a subset of devices known as “thermal radiation thermometers”.

 Sometimes, especially near ambient temperatures, readings may be subject to error due to the reflection of radiation from a hotter body—even the person holding the instrument—rather than radiated by the object being measured, and to an incorrectly assumed emissivity. The design essentially consists of a lens to focus the infrared thermal radiation on to a detector, which converts the radiant power to an electrical signal that can be displayed in units of temperature after being compensated for ambient temperature. This permits temperature measurement from a distance without contact with the object to be measured. A non-contact infrared thermometer is useful for measuring temperature under circumstances where thermocouples or other probe-type sensors cannot be used or do not produce accurate data for a variety of reasons.

Today’s victim, like my replacement for the precursor pulse oximeter teardown subject, came to me via a May 2024 Meh promotion. A two-pack had set me back only $10, believe it or not (I wonder what they would have cost me in 2020?). One entered our home health care gear stable, while the other will be disassembled here. I’ll start with some stock photos:

Now for some as-usual teardown-opening box shots:

Speaking of opening:

The contents include our patient (of course), a set of AA batteries (which I’ll press into reuse service elsewhere):

and a couple of slivers of literature:

Now for the star of the show, as usual accompanied by a 0.75″ (19.1 mm) diameter U.S. penny for size comparison purposes (the Meh product page claims that the infrared thermometer is “small” and “lightweight” but isn’t any more specific than that). Front:

They really don’t think that sticker’s going to deter me, do they?

Back:

A closeup of the “LCD Backlit display with 32 record memory”, with a translucent usage-caution sticker from-factory stuck on top of it:

Right (as defined from the user’s perspective) side, showcasing the three UI control buttons:

Left:

revealing the product name (Safe-Mate LX-26E, also sold under the Visiomed brand name) and operating range (2-5 cm). The label also taught me something new; the batteries commonly referred to as “AAs” are officially known as “LR6s”:

Top:

Another sticker closeup:

And bottom, showcasing the aforementioned-batteries compartment “door”:

Flipping it open reveals a promising screw-head pathway inside:

although initial subsequent left-and-right half separation attempts were incomplete in results:

That said, they did prompt the battery-compartment door to fall out:

I decided to pause my unhelpful curses and search for other screw heads. Nothing here:

or here:

Here either, although I did gain a fuller look at the switches (complete with intriguing connections-to-insides traces) and their rubberized cover:

A-ha!

That’s more like it (complete with a trigger fly-away):

I was now able to remove the cap surrounding the infrared receiver module:

Followed by the module itself, along with the PCB it was (at the moment) connected to:

Some standalone shots of the module and its now-separated ribbon cable:

And of the other now-disconnected ribbon cable, this one leading to the trifecta of switches on the outside:

Here’s the front of the PCB, both in with-battery-compartment overview:

and closeup perspectives, the latter more clearly revealing its constituent components, such as the trigger switch toward the bottom, an IC from Chipsea Technologies labeled “2012p1a” toward the top, and another labeled:

CHIPSEA
18M88-LQ
2020C1A

at the top (reader insights into the identities of either/both of these ICs is greatly appreciated):

And here’s the piezo buzzer-dominant, comparatively bland (at least at first glance) backside:

which became much more interesting after I lifted away the “LCD Backlit display with 32 record memory”, revealing a more complex-PCB underside than I’d originally expected:

That’s all I’ve got for today. What did you find surprising, interesting and/or potentially underwhelming about the design? Let me (and your fellow readers) know in the comments!

—Brian Dipert is the Editor-in-Chief of the Edge AI and Vision Alliance, and a Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the company’s online newsletter.

Related Content

• Peering inside a Pulse Oximeter
• Thermometer measures temperature without contact
• Teardown: A smartwatch with an athletic tradition
• Teardown: Inside the art of pulse oximetry
• Teardown: Fitness band hardware
• Teardown: A fitness tracker that drives chip demand
• Teardown: Misfit Shine 2 and the art of power management

The post Taking a peek inside an infrared thermometer appeared first on EDN.

India’s premier expo, Light + LED Expo India 2024, is set to showcase advanced products in LED and intelligent lighting solutions from 21st to 23rd November 2024 at Yashobhoomi (IICC), Dwarka, Delhi. With 240+ exhibitors from six countries, the B2B event will present innovative solutions for homes, high rises, architecture, infrastructure, and everything in between.

With LED light emerging as a powerful catalyst in India’s energy efficiency journey, its applications have spread from households and industrial spaces to more complex and customised needs for architecture and interior design, urban infrastructure and smart city projects. Government-backed initiatives like Unnat Jyoti by Affordable LEDs for All and LED Street Lighting National Programme (SLNP), gave a substantial boost to LED adoption in India while saving costs and energy with environmental benefits. Besides this, the growth of the semiconductor ecosystem in India will revolutionise LED manufacturing, boost domestic production, achieve energy efficiency and contribute to positioning India as a global manufacturing hub for semiconductors and diverse lighting products.

Bringing together India’s lighting and LED ecosystem, the 29th edition of Light + LED Expo India will feature 240+ exhibitors and about 1,000+ brands showcasing their products, across a gross area of 14,000 sqm at Yashobhoomi, Delhi, Dwarka. Taking the expo to a whole new level, this year the show will feature 126 new exhibitors and has more participation from lighting automation companies than the previous editions, enhancing the solutions portfolio. Besides India, the expo will present participation from six countries including China, Finland, Germany, Italy, Taiwan and the UAE. Participants include brands like BAG, Calcom, Caterlux, JN Lighting, Kevin Electrochem, Lumens Technologies, Optiks Mechatronics, Power Pallazo, Talenteq, Tinge, Uniglobus, Zylos and many other prestigious names.

Ahead of the show, Shri Piyush Goyal, Hon’ble Minister of Commerce and Industry, Government of India, expressed his thoughts: “The Government of India has undertaken collaborative initiatives to establish a strong LED ecosystem in India. Initiatives like the Unnat Jyoti by Affordable LEDs for All (UJALA) and LED Street Lighting National Programme (SLNP) have significantly bolstered the adoption of energy-efficient lighting solutions across the nation, leading to widespread cost savings, reduced energy consumption and environmental benefits. I am hopeful that this expo and summit will serve as an ideal platform for stakeholders to come together, exchange ideas, showcase advancements and further contribute to the growth and sustainability of the LED industry in India.”

The upcoming event will present dynamic workshops and expert-led sessions, a certification workshop and a conference. The knowledge sessions have been planned in association with the Illuminating Engineering Society (IES), Women in Lighting (WIL), Lighting Designers Association of India (LiDAI) and Electric Component Manufacturers’ Association (ELCOMA). Attendees will explore the innovative applications of lighting technology within India’s cultural landscape, covering topics such as the role of lighting in architecture, the future of entertainment lighting, and advancements in connected lighting systems. The sessions will also address the creative potential of drone light shows, smart lighting solutions, human-centric designs, and India’s emergence as a global lighting hub. Key discussions on ‘circadian lighting’ and the evolving language of lighting design promise attendees’ valuable insights into the industry’s latest trends and technologies.

Mr Parag Bhatnagar, President, of the Electric Lamp and Component Manufacturers Association of India (ELCOMA) commented: “In the last few years there were some disruptions because of the technology changes, however, there are many opportunities as India is growing. You look at any segment whether it is infrastructure or modern office space which is growing by 30% or even the recent PLI scheme of the government – the CAPEX cycle is triggered and there is growth in the industry. There is an opportunity to upgrade the industry. I think Light + LED Expo India is a very prominent platform where the entire lighting fraternity will come together and there will be knowledge sharing around government policies, standards and innovation and especially, the new initiatives around lighting design. I invite the entire lighting fraternity and all ELCOMA members to Light + LED Expo India taking place from 21 – 23 November 2024 at Yashobhoomi (IICC), Dwarka, Delhi.”

What makes the expo more relevant is the fact that the Indian LED lighting industry in 2023 stood at USD 4.2 billion which is expected to reach USD 23.2 Billion by 2032, growing at a rate of 20.91% during 2023-2032, according to a report from Research and Markets. Mr Raj Manek, Executive Director and Board Member, Messe Frankfurt Asia Holdings Ltd, shared: “According to leading industry research companies, the LED lighting industry is expected to grow about five-fold by 2032. At this juncture, the Light + LED Expo India will exhibit an array of products and solutions before the industry, with new launches that will take place at the show.  Entering the 29th edition, the expo has received a great response from the participating companies ready to display an advanced showcase that will aid in addressing the evolving needs of the Indian landscape. I feel proud that the show highlights the growth of India’s lighting and LED industry with an emphasis on sustainability in the segment.”

The exhibition has garnered strong support from India’s leading industry associations and government bodies such as Ministry of Electronic & Information Technology (MeitY), Ministry of Commerce & Industry, Energy Efficiency Services Limited (EESL) Ministry of Power, LiDAI (Lighting Designers Association of India), CREDAI-MCHI, Council of Architecture (CoA), Luminaire Accessories Components Manufacturers Association (LACMA), Indian Building Congress (IBC), Solar Energy Society of India (SESI), Bombay Suburban Electric Supply (BSES), The Calcutta Electric Traders Association and the Secunderabad Electric Traders Association.

The show is organised by Messe Frankfurt Trade Fairs India Pvt Ltd in association with ELCOMA. Light + LED Expo India is part of Messe Frankfurt’s Light + Building Technology fair portfolio, which is headlined by the biennial Light + Building event in Frankfurt, Germany.

The post Light + LED Expo India 2024 to shine a spotlight on smart, energy-efficient and human-centric lighting solutions for the diverse needs of India’s architecture, infrastructure and more appeared first on ELE Times.

Highly integrated biosensor device combines input channel for cardio and neurological sensing with motion tracking and embedded AI core

Demonstration to take place at Electronica 2024, Munich, November 12-15

STMicroelectronics, a global semiconductor leader serving customers across the spectrum of electronics applications, has introduced a new bio-sensing chip for the next generations of healthcare wearables like smart watches, sports bands, connected rings, or smart glasses. The ST1VAFE3BX chip combines a high-accuracy biopotential input with ST’s proven inertial sensing and AI core, which performs activity detection in the chip to ensure faster performance with lower power consumption.

“Wearable electronics is the critical enabling technology for the upsurge in individual health awareness and fitness. Today, everyone can have heart-rate monitoring, activity tracking, and geographical location on their wrist,” said Simone Ferri, APMS Group VP, MEMS Sub-Group General Manager at STMicroelectronics. “Our latest biosensor chip now raises the game in wearables, delivering motion and body-signal sensing in an ultra-compact form-factor with frugal power budget.”

Analysts at Yole Development see opportunities for wearable monitors transcending the general wellness market, including consumer healthcare devices that are approved by health organizations and available over the counter. By creating a complete precision sensor input in silicon, ST’s chip-design experts are facilitating innovation in all segments, with advanced capabilities such as heart-rate variability, cognitive function, and mental state.

The ST1VAFE3BX provides opportunities to extend wearable applications beyond the wrist to other locations on the body, such as intelligent patches for lifestyle or medical monitoring purposes. ST customers BM Innovations GmbH (BMI) and Pison are working at the frontiers in this sector and have quickly adopted the new sensor to drive new-product development.

BMI is an electronic design contracting company experienced in wireless sensing and with an extensive portfolio of projects including several leading-edge heart rate and performance monitoring systems. “ST’s new biosensor has enabled us to develop the next generation of precise athlete performance monitoring systems including ECG analysis in a chest band or a small patch,” said Richard Mayerhofer, Managing Director BM innovations GmbH. “Combining the analog signal from the vAFE with motion data from the acceleration sensor within a compact single package facilitates precise and context-aware data analysis. And with additional support for our AI algorithms directly on the sensor, this is exactly what we have been looking for.”

David Cipoletta, CTO of Pison, a developer focusing on advanced technologies to enhance health and human potential, added, “ST’s new biosensor stands out as a great solution for smartwatch gesture recognition, cognitive performance, and neurological health. Leveraging this advancement, we have significantly enhanced the functionality and user experience of our wearable devices.”

The ST1VAFE3BX is in production now in a 2mm x 2mm 12-lead LGA package and available from the eSTore (free samples available) and distributors from $1.50 for orders of 1000 units.

Visitors to Electronica 2024, the major industry trade event happening in Munich November 12-15, can see the ST1VAFE3BX in a sensing technologies demonstration at the ST booth, Hall C3 101. More information is available online at www.st.com/biosensors

Further technical information

The analog front-end circuits for biopotential sensors are difficult to design and subject to unpredictable effects such as skin preparation and the position of electrodes attached to the body. The ST1VAFE3BX provides a complete vertical analog front end (vAFE) that simplifies the detection of different types of vital signs that can indicate physical or emotional state.

Manufacturers of wellness and healthcare devices can thus extend their product ranges to include functionality such as electrocardiography (ECG), electroencephalography (EEG), seismocardiography (SCG), and electroneurography (ENG). This can drive the emergence of new devices that are affordable, easy to use, and reliably indicate health status or physiological responses to events such as stress or excitement. The future could contain a greater diversity of wearable devices that can contribute towards enhanced healthcare, fitness, and self-awareness.

Bringing this precision front end on-chip, the ST1VAFE3BX is building on ST’s established competencies in MEMS (microelectromechanical systems) devices by integrating an accelerometer for inertial sensing. The accelerometer provides information about the wearer’s movement, which is synchronized with the biopotential sensing to help the application infer any link between measured signals and physical activity.

The ST1VAFE3BX also integrates ST’s machine-learning core (MLC) and finite state machine (FSM) that enable product designers to implement simple decision trees for neural processing on the chip. These AI skills let the sensor handle functions such as activity detection autonomously, offloading the main host CPU to accelerate system responses and minimize power consumption. In this way, ST’s sensors let smart devices provide more sophisticated functions and operate for longer between battery charging, enhancing usability. ST also provides software tools like MEMS Studio in the ST Edge AI Suite dedicated to helping designers unleash the maximum performance from the ST1VAFE3BX, including tools for configuring decision trees in the MLC.

The ST1VAFE3BX’s bio-detection signal channel comprises the vAFE with programmable gain and 12-bit ADC resolution. The maximum output data rate of 3200Hz is suitable for a wide variety of biopotential measurements to quantify heart, brain, and muscular activity.

The device is powered from a supply voltage in the range 1.62V to 3.6V and has typical operating current of just 50µA, which can be cut to just 2.2µA in power-saving mode.

The integrated low-noise accelerometer has programmable full-scale range from ±2g to ±16g.

In addition to the machine-learning core and programmable finite state machine, which can provide functionality such as activity detection, the ST1VAFE3BX implements advanced pedometer, step detector, and step counting functions.

The post STMicroelectronics’ innovative biosensing technology enables next-generation wearables for individual healthcare and fitness appeared first on ELE Times.

Following the announcement in February of a conditional commitment, as part of the Biden–Harris Administration’s Investing in America agenda the US Department of Energy (DOE) has now confirmed a $544m loan ($481.5m of principal and $62.5m of capitalized interest) to compound semiconductor wafer maker SK Siltron CSS LLC of Auburn, MI, USA (a subsidiary of South Korea-based wafer manufacturer SK Siltron, a part of South Korea’s second-largest conglomerate SK Group) to expand American manufacturing of high-quality silicon carbide (SiC) wafers for electric vehicle (EV) power electronics...

Singapore-based wet etch and clean solutions provider NexGen Wafer Systems has launched SERENO its latest multi-chamber platform (available now for orders, with first deliveries starting in first-quarter 2025)...

Solid State Physics Laboratory, a research arm of the Indian Ministry of Defence’s Defence Research and Development Organisation (DRDO), has developed indigenous processes for growing and manufacturing 4-inch-diameter silicon carbide (SiC) wafers, as well as fabricating gallium nitride (GaN) high-electron-mobility transistors (HEMTs) up to 150W and monolithic microwave integrated circuits (MMICs) up to 40W for applications operating at up to X-band frequencies...

Sivers Semiconductors AB of Kista, Sweden (which supplies RF beam-former ICs for SATCOMs and photonic lasers for AI data centers) says that its board of directors has decided to put on hold its discussions with byNordic Acquisition Corp (BYNO) — a publicly traded special purpose acquisition company (SPAC) — regarding the proposed business combination with its subsidiary Sivers Photonics Ltd of Glasgow, Scotland, UK and release BYNO to seek other merger candidates...

NS Nanotech Inc of Ann Arbor, MI, USA — a University of Michigan Electrical and Computer Engineering (ECE) spin-off co-founded by professor Zetian Mi in 2017 that develops gallium nitride nanowire LEDs for visible displays and UVC disinfection applications — has appointed John Bayne to its board of directors...

Cree LED Inc of Durham, NC, USA (a Penguin Solutions brand) has launched its new CV28D LEDs with FusionBeam Technology, providing an advance for the LED signage market. The CV28D LED combines the latest through-hole and surface-mount (SMD) RGB LED technology, delivering what is claimed to be superior directionality, image quality and resolution in a durable, easy-to-assemble package...

I got so fed up with the stupid interface on the front of my automatic cat feeders that I decided to make a web interface and use the ESP8266 to control them. They are very simple devices. Across two different brands of feeders I have they use the same internal mechanism, so this should work pretty universally across all generic-looking cat feeders... I was going to design a custom PCB but the circuit is so simple it was pointless and would've taken weeks to arrive. I cut the original wiring harness and crimped on JST-XH connectors to make it look somewhat professional. cat feeder from brand #1 wired to my board cat feeder from brand #2 wired to my board The prefboard I made (I made 3x of them) You can check out the code and some more images of the feeders and board (front/back/etc) here: https://github.com/captmicr0/EspCatFeeder submitted by /u/rhyno95_ [link] [comments]

On 14 November, Tokyo-based Mitsubishi Electric Corp is commencing shipment of samples of a silicon carbide (SiC) metal-oxide-semiconductor field-effect transistor (MOSFET) bare die for use in drive-motor inverters of electric vehicles (EVs), plug-in hybrid vehicles (PHEVs) and other electric vehicles (xEVs)...

Often, one needs a simple low voltage sinusoidal oscillator with good amplitude and frequency stability and low harmonic distortion; here, the Peltz oscillator becomes a viable candidate. Please see the Peltz oscillator Analog Devices Wiki page here and a discussion on my Peltz oscillator here.

Wow the engineering world with your unique design: Design Ideas Submission Guide

Shown in Figure 1, the Peltz oscillator requires only two transistors, one capacitor, one inductor and one resistor. In this configuration, the output voltage is a ground referenced, direct coupled, low distortion sinewave, swinging above and below ground at ~1 Vbe, while operating from a low negative supply voltage (AAA battery).

Figure 1 Basic configuration of a Peltz oscillator with a low component count yielding a low distortion sinewave output.

The oscillating frequency is shown:

A simplified analysis shows the minimum negative supply voltage (Vee) is:

Where Vt is the Thermal Voltage (kT/q), Z is the total impedance “seen” at the parallel resonant LC network, Vbe is the base emitter voltage of Q1 [Vt*ln(Ic/Is)], and Is is the transistor saturation current.

Here’s an example with a pair of 2N3904s, a 470 µH inductor, 0.22 µF capacitor, and a 510 Ω bias resistor, powered from a single AAA cell (the oscillator actually works at ~0.7 VDC), producing a stable, low noise ~16 kHz sinewave as shown in Figure 2, Figure 3, and Figure 4.

Figure 2 Peltz oscillator output with a clean 16 kHz sinewave.

Figure 3 Spectral view of sinewave showing fundamental as well as 2nd and 3rd harmonics.

Figure 4 Zoomed in view of ~16 kHz sinewave.

Note the output frequency, peak to peak amplitude and overall waveform quality is not bad for a 5-element oscillator!

Michael A Wyatt is a life member with IEEE and has continued to enjoy electronics ever since his childhood. Mike has a long career spanning Honeywell, Northrop Grumman, Insyte/ITT/Ex-elis/Harris, ViaSat and retiring (semi) with Wyatt Labs. During his career he accumulated 32 US Patents and in the past published a few EDN Articles including Best Idea of the Year in 1989.

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• The Colpitts oscillator
• Add one resistor to give bipolar LM555 oscillator a 50:50 duty cycle

The post Simple 5-component oscillator works below 0.8V appeared first on EDN.

ROHM Semiconductor has launched surface-mount SiC Schottky barrier diodes (SBDs) that improve insulation resistance by increasing the creepage distance between terminals. The initial lineup includes eight models (SCS2xxxNHR) for automotive applications such as on-board chargers (OBCs) and DC-DC converters (available now), with plans to deploy eight additional models (SCS2xxxN) for industrial equipment such as factory automation (FA) devices (e.g. AC servo motors for industrial robots) and photovoltaic (PV) inverters, power conditioners, uninterruptible power supplies (UPS) etc (scheduled to be available) in December...

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Hey everyone! I’m excited to share my latest project: a tiny, open-source RP2040-based board with an integrated addressable LED matrix. It’s built on a 4-layer PCB, and the LEDs are ultra-small (just 1mm x 1mm each), using WS2812 for full addressability. https://preview.redd.it/5whyzmxtta0e1.jpg?width=1800&format=pjpg&auto=webp&s=f3c11d04357dbf23259972b1255bea51caf96379 https://preview.redd.it/4hhhaijuta0e1.jpg?width=1800&format=pjpg&auto=webp&s=dd44466247e926234ba572ed3b7222cdddf1bdc9 submitted by /u/TheBusDriver69 [link] [comments]

Silicon carbide wafer manufacturing technology firm TekSiC AB of Linköping, Sweden has appointed Joachim Tollstoy as chief executive officer, effective 7 October. With over 15 years of leadership experience, Tollstoy has an understanding of market dynamics that TekSiC reckons will be essential as it navigates the evolving landscape of silicon carbide manufacturing...

I mentioned recently that for the third time in roughly a decade, a subset of the electronics suite in my residence had gotten zapped by a close-proximity lightning storm. Although this follow-up writeup, one of a planned series, was already proposed to (and approved by) Aalyia at the time, subsequent earlier-post comments exchanges with a couple of readers were equal parts informative and validating on this one’s topical relevance.

First off, here’s what reader Thinking_J had to say:

Only 3 times in a 10-year span, in the area SW of Colorado Springs?

Brian, you appear to be lucky.

https://www.cbsnews.com/colorado/news/lightning-dangers-traditional-beliefs-researchers-colorado-update-ideas-storms-denver/

My response:

Southwest of Golden (and Denver, for that matter), not Colorado Springs, but yes, the broader area is active each year’s “monsoon season”:

https://climate.colostate.edu/co_nam.html

The “monsoon season” I was referencing historically runs from mid-June through the end of September. Storms normally fire up beginning mid-afternoon and can continue overnight and into the next morning. As an example of what they look like, I grabbed a precipitation-plot screenshot during a subsequent storm this year; I live in Genesee, explicitly noted on the map:

Wild, huh?

Then there were the in-depth thoughts of reader “bdcst”, in a posting only the first half of which I’ve republished here for brevity (that said, I encourage you to read the post in its entirety at the original-published location):

Hi Brian,

Several things come to mind. First is, if you think it was EMP, then how will moving your copper indoors make a difference unless you live in a Faraday cage shielded home? The best way to prevent lightning induced surges from entering your equipment via your network connection, is to go to a fiber drop from your ISP, cable or telecom carrier. You could also change over to shielded CAT-6 Ethernet cable.

 At my broadcast tower sites, it’s the incoming copper, from the tower, or telephone system or from the power line itself that brings lighting induced current indoors. Even with decent suppressors on all incoming copper, the only way to dissipate most of the differential voltage from the large current spikes is with near zero ohms bonding between every piece of equipment and to a single very low impedance earth ground point. All metal surfaces in my buildings are grounded by large diameter flexible copper wire, even the metal entrance door is bonded to it bypassing the resistance of its hinges.

 When I built my home at the end of a long rural power line, I experienced odd failures during electrical storms. I built my own power line suppressor with the largest GE MOV’s I could find. That eliminated my lightning issues. Of course, surge suppressors must have very low resistance path to ground to be effective. If you can’t get a fiber drop for your data, then do install several layers of Ethernet suppressors between the incoming line and your home. And do install at least a small AC line suppressor in place of a two-pole circuit breaker in your main panel, preferably at the top of the panel where the main circuit breaker resides.

My response, several aspects of which I’ll elaborate on in this writeup:

Thanks everso for your detailed comments and suggestions. Unfortunately, fiber broadband isn’t an option here; I actually feel fortunate (given its rural status) to have Gbit coax courtesy of Comcast:

 https://www.edn.com/a-quest-for-faster-upstream-bandwidth/

 Regarding internal-vs-external wired Ethernet spans, I don’t know why, but the only times I’ve had Ethernet-connected devices fry (excluding coax and HDMI, which also have been problematic in the past) are related to those (multi-port switches, to be precise) on one or both ends of an external-traversed Ethernet span. Fully internal Ethernet connections appear to be immune. The home has cedar siding and of course there’s also insulation in the walls and ceiling, so perhaps that (along with incremental air gaps) in sum provides sufficient protection?

 Your question regarding Ethernet suppressors ties nicely into one of the themes of an upcoming planned blog post. I’ve done only rudimentary research so far, but from what I’ve uncovered to date, they tend to be either:

1. Inexpensive but basically ineffective or
2. Incredibly expensive, but then again, replacement plasma TVs and such are pricey too (http://www.edn.com/electronics-blogs/brians-brain/4435969/lightning-strike-becomes-emp-weapon-)

Plus, I’m always concerned about bandwidth degradation that may result from the added intermediary circuitry (same goes for coax). Any specific suggestions you have would be greatly appreciated.

 Thanks again for writing!

Before continuing, an overview of my home network will be first-time informative for some and act as a memory-refresher to long-time readers for whom I’ve already touched on various aspects. Mine’s a two-story home, with the furnace room, roughly in the middle of the lower level, acting as the networking nexus. Comcast-served coax enters there from the outside and, after routing through my cable modem and router, feeds into an eight-port GbE switch. From there, I’ve been predominantly leveraging Ethernet runs originally laid by the prior owner.

In one direction, Cat 5 (I’m assuming, given its age, versus a newer generation) first routes through the interstitial space between the two levels of the house to the far wall of the family room next to the furnace room, connecting to another 8-port GbE switch. At that point, another Ethernet span exits the house, is tacked to the cedar wood exterior and runs to the upper-level living room at one end of the house, where it re-enters and connects to another 8-port GbE switch. In the opposite direction, another Cat 5 span exits the house at the furnace room and routes outside to the upper-level master bedroom at the other end of the house, where it re-enters and connects to a five-port GbE switch. Although the internal-only Ethernet is seemingly comprised of conventional unshielded cable, judging from its flexibility, I was reminded via examination in prep for tackling this writeup that the external wiring is definitely shielded, not that this did me any protective good (unsurprisingly, sadly, given that externally-routed shielded coax cable spans from room to room have similarly still proven vulnerable in the past).

Normally, there are four Wi-Fi nodes in operation, in a mesh configuration comprised of Google Nest Wifi routers:

1. The router, in the furnace room downstairs
2. A mesh point in the master bedroom upstairs at one end of the house
3. Another in the living room upstairs at the other end of the house
4. And one more downstairs, in an office directly below the living room

Why routers in the latter three cases, versus less expensive access points? In the Google Nest Wifi generation, versus with the Google OnHub and Google Wifi precursors (as well as the Google Nest Wifi Pro successor, ironically), access points are only wirelessly accessible; they don’t offer Ethernet connectivity as an option for among other things creating a wired “mesh” backbone (you’ll soon see why such a backbone is desirable). Plus, Google Nest Wifi Routers’ Wi-Fi subsystems are more robust; AC2200 MU-MIMO with 4×4 on 5 GHz and 2×2 on 2.4GHz, versus only AC1200 MU-MIMO Wi-Fi 2×2 on both 2.4 GHz and 5 GHz for the Google Nest Wifi Point. And the Point’s inclusion of a speaker is a don’t-care (more accurate: a detriment) to me.

I’ve augmented the already-existing Ethernet wiring when we bought the house with two other notable additional spans, both internal-only. One runs from the furnace room to my office directly above it (I did end up replacing the original incomplete-cable addition with a fully GbE-complaint successor). The other goes through the wall between the family room and the earlier-mentioned office beyond it (and below the living room), providing it with robust Wi-Fi coverage. As you’ll soon see, this particular AP ended up being a key (albeit imperfect) player in my current monsoon-season workaround.

Speaking of workarounds, what are my solution options, given that the outdoor-routed Ethernet cable is already shielded? Perhaps the easiest option would be to try installing Ethernet surge protectors at each end of the two outdoors-dominant spans. Here, for example are some that sell for $9.99 a pair at Amazon (and were discounted to $7.99 a pair during the recent Prime Fall Days promotion; I actually placed an order but then canceled it after I read the fine print):

As the inset image shows and the following teardown image (conveniently supplied by the manufacturer) further details, they basically just consist of a bunch of diodes:

This one’s twice as expensive, albeit still quite inexpensive, and adds an earth ground strap:

Again, nothing but diodes (the cluster of four on each end are M7s; I can’t read the markings on the middle two), though:

Problem #1: diving into the fine print (therefore my earlier mentioned order cancellation), you’ll find that they only support passing 100 Mbit Ethernet through, not GbE. And problem #2; judging from the user comments published on both products, they don’t seem to work, at least at the atmospheric-electricity intensities my residence sees.

Ok, then, if my observation passes muster that internal-only Ethernet spans, even unshielded ones, are seemingly EMI-immune, why not run replacement cabling from the furnace room to both upper-level ends of the house through the interstitial space between the levels, as well as between the inner and outer walls? That may indeed be what I end up biting the bullet and doing, but the necessary navigation around (and/or through) enroute joists, ductwork and other obstacles is not something that I’m relishing, fiscally or otherwise. In-advance is always preferable to after-the-fact when it comes to such things, after all! Ironically, right before sitting down to start writing this post, I skimmed through the final print edition of Sound & Vision magazine, which included a great writeup by home installer (and long-time column contributor) John Sciacca. There’s a fundamentally solid reason why he wrote the following wise words!

A few of my biggest tips: Prewire for everything (a wire you aren’t using today might be a lifesaver tomorrow!), leave a conduit if possible…

What about MoCA (coax-based networking) or powerline networking? No thanks. As I’ve already mentioned, the existing external-routed coax wiring has proven vulnerable to close-proximity lightning, too. If I’m going to run internally routed cable instead, I’ll just do Ethernet. And after several decades’ worth of dealing with powerline’s unfulfilled promise due to its struggles to traverse multiple circuit breakers and phases, including at this house (which has two breaker boxes, believe it or not, the original one in the garage and a newer supplement in the furnace room), along with injected noise from furnaces, air conditioning units, hair dryers, innumerable wall warts and the like, I’ve frankly collected more than enough scars already. But speaking of breaker boxes, by the way, I’ve already implemented one of the earlier documented suggestions from reader “bdcst”, courtesy of an electrician visit a few years back:

The final option, which I did try (with interesting results), involved disconnecting both ends of the exterior-routed Cat 5 spans and instead relying solely on wireless backbones for the mesh access points upstairs at both ends of the house. As setup for the results to come, I’ll first share what the wired-only connectivity looks like between the furnace room and my office directly above it. I’m still relying predominantly on my legacy, now-obsolete (per Windows 8’s demise) Windows Media Center-based cable TV-distribution scheme, which has a convenient built-in Network Tuner facility accessible via any of the Xbox 360s acting as Windows Media Extenders:

In preparation for my external-Ethernet severing experiment, to maximize the robustness of the resultant wireless backbone connectivity to both ends of the house, I installed a fifth Google Nest Wifi router-as-access point in the office. It indeed resulted in reasonably robust, albeit more erratic, bandwidth between the router and the access point in the living room, first as reported in the Google Home app:

and then by Windows Media Center’s Network Tuner:

I occasionally experienced brief A/V dropouts and freezes with this specific configuration. More notably, the Windows Media Center UI was more sluggish than before, especially in its response to remote control button presses (fast-forward and -rewind attempts were particularly maddening). Most disconcerting, however, was the fact that my wife’s iPhone now frequently lost network connectivity after she traversed from one level of the house to the other, until she toggled it into and then back out of Airplane Mode.

One of the downsides of mesh networks is that, because all nodes broadcast the exact same SSID (in various Google Wifi product families’ case), or the same multi-SSID suite for other mesh setups that use different names for the 2.4 GHz, 5 GHz, and 6 GHz beacons, it’s difficult (especially with Google’s elementary Home utility) to figure out exactly what node you’re connected to at any point in time. I hypothesized that her iPhone was stubbornly clinging to the now-unusable Wi-Fi node she was using before versus switching to the now-stronger signal of a different node in her destination location. Regardless, once I re-disconnected the additional access point in my office, her phone’s robust roaming behavior returned:

But as the above screenshot alludes to, I ended up with other problems in exchange. Note, specifically, the now-weak backbone connectivity reported by the living room node (although, curiously, connectivity between the master bedroom and furnace room remained solid even now over Wi-Fi). The mesh access point in the living room was, I suspect, now wirelessly connected to the one in the office below it, ironically a shorter node-to-node distance than before, but passing through the interstitial space between the levels. And directly between the two nodes in that interstitial space is a big hunk of metal ductwork. Note, too, that the Google Nest Wifi system is based on Wi-Fi 5 (802.11ac) technology, and that the wireless backbone is specifically implemented using the 5 GHz band, which is higher-bandwidth than its 2.4 GHz counterpart but also inherently shorter-range. The result was predictable:

The experiment wasn’t a total waste, though. On a hunch, I tried using the Xfinity Stream app on my Roku to view Comcast-sourced content instead. The delivery mechanism here is completely different: streamed over the Internet and originating from Comcast’s server, versus solely over my LAN from the mini PC source (in all cases, whether live, time-shifted or fully pre-recorded, originating at my Comcast coax TV feed via a SiliconDust HDHomeRun Prime CableCARD intermediary). I wasn’t direct-connecting to premises Wi-Fi from the Roku; instead, I kept it wired Ethernet-connected to the multi-port switch as before, leveraging the now-wireless-backbone-connected access point also connected to the switch there instead. And, as a pleasant surprise to me, I consistently received solid streaming delivery.

What’s changed? Let’s look first at the video codec leveraged. The WTV “wrapper” (container) format now in use by Windows Media Center supersedes the DVR-MS precursor with expanded support for both legacy MPEG-2 and newer MPEG-4 video. And indeed, although a perusal of a recent recorded-show file in Window Explorer’s File Properties option was fruitless (the audio and video codec sections were blank), pulling the file into VLC Media Player and examining it there proved more enlightening. There were two embedded audio tracks, one English and the other Spanish, both Dolby AC3-encoded. And the video was encoded using H.264, i.e., MPEG-4 AVC (Part 10). Interestingly, again according to VLC, it was formatted at 1280×720 pixel resolution and a 59.940060 fps frame rate. And the bitrate varied over time, confirmative of VBR encoding, with input and demuxed stream bitrates both spiking to >8,000 kb/sec peaks.

The good news here, from a Windows Media Center standpoint, is two-fold: it’s not still using archaic MPEG-2 as I’d feared beforehand might have been the case, and the MPEG-4 profile in use is reasonably advanced. The bad news, however, is that it’s only using AVC, and at a high frame rate (therefore bitrate) to boot. Conversely, Roku players also support the more advanced HEVC and VP9 video codec formats (alas, I have no idea what’s being used in this case). And, because the content is streamed directly from Comcast’s server, the Roku and server can communicate to adaptively adjust resolution, frame rate, compression level and other bitrate-related variables, maximizing playback quality as WAN and LAN bandwidth dynamically vary.

For now, given that monsoon season is (supposedly, at least) over until next summer, I’ve reconnected the external Cat 5 spans. And it’s nice to know that when the “thunderbolt and lightning, very, very frightening” return, I can always temporarily sever the external Ethernet again, relying on my Rokus’ Xfinity Stream apps instead. That said, I also plan to eventually try out newer Wi-Fi technology, to further test the hypothesis that “wires beat wireless every time”. Nearing 3,000 words, I’ll save more details on that for another post to come. And until then, I as-always welcome your thoughts in the comments!

—Brian Dipert is the Editor-in-Chief of the Edge AI and Vision Alliance, and a Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the company’s online newsletter.

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