https://community.element14.com/technologies/sensor-technology/Automobiles, computers, medical devices, a staggering array of consumer electronics—these are just a few of the places you'll find sensor technology. Join the Sensors group and stay current on all the latest developments in this key technology.en-USTelligent Community 12https://community.element14.com/technologies/sensor-technology/b/blog/posts/monitoring-mains-current-experimenting-with-the-sct013-current-clampWed, 17 Jun 2026 18:45:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:c3192a7f-b6b4-4e3b-a51d-a668909b9e5bshabazTable of Contents Introduction What Is It? Sensitivity Testbed ‘Scope Traces Example ADC Circuit Summary Introduction The SCT013 (sometimes called SCT-013) is popular in a lot of home automation projects, for monitoring the current consumption of mains devices and circuits. There are several models of it, intended for different current ranges. Due to a lack of time I decided to experiment with an SCT013 in a not-very-thorough way. What Is It? The SCT013 is a clampable current transformer; there is a winding and two halves of a ferrite core inside, and the plastic shell clips onto a single mains wire (which then becomes a single-turn primary winding for the transformer). An AC current flows in the secondary winding, i.e. the coil of wire inside the clamp. The SCT013 has a specified frequency range of 50 Hz to 1 kHz. Note that as with all clamps, the SCT013 need to be used with a single mains conductor (for instance usually live, or perhaps neutral), and not the entire mains flex! There is a resistor across the coil (it’s known as a burden resistor, and is built-in on most SCT013 models but check the specs; never operate the transformer without it!) through which current flows. Screened cable (terminated with a 3.5 mm audio plug) is attached across the resistor, so that a voltage proportional to the current can be measured relatively safely, by just connecting a multimeter (set to AC voltage) across the two terminals, or attach those two terminals to an oscilloscope, or connect to an ADC circuit (either to differential inputs, or, easier, attach the shield to a mid-rail, and connect the tip to a single-ended ADC input) and sample at a few hundred Hz. Note that in electrically noisy environments, filtering or perhaps even ADC isolation may be needed, if you think noise may be picked up along the screened cable, i.e. usually common-mode noise. Also, note that despite there being isolation, care still needs to be taken due to the proximity with mains wiring. Sensitivity There are SCT013 models that are 5A 1V or 15A 1V rated, and there are other options too. Note that the 100A model can be supplied as a 2000-turn clamp without a built-in resistor. Here is how to interpret the sensitivity of each model in terms of millivolts per amp: Model Rated Input (A) Rated Output (V) Sensitivity (mV/A) -005 5 1 200 -010 10 1 100 -015 15 1 66.67 -020 20 1 50 -025 25 1 40 -030 30 1 33.3 -050 50 1 20 -060 60 1 16.67 -100 100 1 10 -100 100 50 mA (requires external resistor) User-selectable. R = 2000 * (S/1000) where S is in mV/A. Example: For 10mV/A, R=20 ohm) If there is no built-in resistor fitted, the formula R = Turns * (S/1000) can be used for any current transformer, where Turns is the Sec:Pri ratio, i.e. 2000 for the SCT013, and S is in mV/A. Testbed I used a mains breakout box to bring out the live connection, so I could place current clamps on the wire. The clamps were connected to an oscilloscope. I used an SCT013-005 model, i.e. 200mV/A sensitivity. For the load, I used a mains fan set to its top speed because it’s a warm day! ‘Scope Traces For this first test, I compared the SCT013 with a Pico Tech TA018 current probe. The TA018 was set to 100mV per amp. The TA018 trace in yellow is a fraction shaky, because it is a more complicated probe (the TA018 responds from 20 kHz down to DC, it responds to magnetic fields). Measured Output (mV RMS) Calculated Current (mA RMS) SCT013 (Red trace) 62.33 311 TA018 (Yellow trace) 29.63 296 I compared the SCT013 with a Yokogawa current clamp which is AC-responding only. The Yokogawa clamp outputs 10mV per amp, and has a frequency response of 20 Hz to 20 kHz. Measured Output (mV RMS) Calculated Current (mA RMS) SCT013 (Red trace) 62.42 312 Yokogawa (Yellow trace) 2.966 296 As can be seen, the TA018 and the Yokogawa clamp measurements agree with each other, and the SCT013 measured around 5% higher. Despite the very basic ‘scope shots for now, I think that’s fairly conclusive, the SCT013 will provide a usable measurement, but don’t expect the accuracy of a decent known-brand clamp. It could be interesting to measure the frequency response (for example, by using a power amplifier and looping the cable through the clamp several times), but again, time is limited, and I didn’t have a need, considering that the SCT013 will only ever be used for a ballpark figure, not for accuracy, where I’d use a known-brand clamp. Example ADC Circuit I tried the following circuit (using an ADC in-built to a microcontroller): There's no protection in case there is a fault and the internal burden resistor is disconnected. In my limited tests, I'm getting good measurements with this, although I need to improve my software. Summary The SCT013 range are affordable current clamps for basic current monitoring needs. The clamps were compared with known-brand ones, using a fan as a load, and the output was monitored with an oscilloscope. The conclusion was that the SCT013 is fine for non-critical measurements. I only tested one SCT013; I don't know if the results are typical for all SCT013 clamps. Note that care must be taken when using current clamps, since they are usually in close proximity to potentially dangerous environments. Thanks for reading.ta018current transformerYokogawaSCT013mainsSCT-013Pico Techcurrent sensorhttps://community.element14.com/technologies/sensor-technology/f/forum/57026/batteryless-temperature-sensor/236082Thu, 11 Jun 2026 19:16:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:47e75b59-7d71-4d28-b3ac-8b8a8ff708d4DABI agree, flat cable would be the way to go.https://community.element14.com/technologies/sensor-technology/f/forum/57026/batteryless-temperature-sensor/236078Thu, 11 Jun 2026 07:55:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:999bf032-f1e9-40ce-9459-858055a3b238obonesIndeed, but in my case, it only goes to the fridge compartment, not the frozen food one. That one does not have auto defrost.https://community.element14.com/technologies/sensor-technology/f/forum/57026/batteryless-temperature-sensor/236076Thu, 11 Jun 2026 07:37:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:fa5d530f-140d-45f8-8876-c9370e661ab3Gough LuiIf you want very thin wires, perhaps try a thermocouple bead to an external reader circuit or meter? You might need some special covering to make it truly air-tight (otherwise you will have frosting issues). - Goughhttps://community.element14.com/technologies/sensor-technology/f/forum/57026/batteryless-temperature-sensor/236074Thu, 11 Jun 2026 02:19:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:3468440f-d9ba-4950-a90f-cb60b9b83075dougwNFC could work, although I haven't tried this specific application. I did however do a battery-less temperature sensor using RFID frequency to transfer power - see Klingmagon .https://community.element14.com/technologies/sensor-technology/f/forum/57026/batteryless-temperature-sensor/236071Wed, 10 Jun 2026 16:15:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:a9f5de5c-e012-47f3-8679-2cc475a5d810beacon_dave[quote userid="121623" url="~/technologies/sensor-technology/f/forum/57026/batteryless-temperature-sensor/236066"]Note that this is a working fridge with a slight auto defrost issue.[/quote] Quite often the auto defrost fridges have a drain hole. I think it leads to a drip tray under the unit rather than just dripping onto the floor. Perhaps there is already an existing route through this drain ?https://community.element14.com/technologies/sensor-technology/f/forum/57026/batteryless-temperature-sensor/236070Wed, 10 Jun 2026 14:15:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:e5e879a9-0632-4917-b9e8-909fba21aec2BigGThere is a new(ish) RFID tech that's on the market, which technically could work. It's called RAIN. https://therainalliance.org/what-is-rain/ However, it may be too expensive for the hobbyist market. I am not sure myself.https://community.element14.com/technologies/sensor-technology/f/forum/57026/batteryless-temperature-sensor/236066Wed, 10 Jun 2026 09:49:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:198519e6-c83e-46bb-bb91-a6842bb04b77michaelkellettI can suggest two alternatives - both of which I use. 1) Use thermocouples with thin wires - OK with most seals. 2) Use pretty much any kind of sensor and drill a hole though the side of the fridge. These suggestions are not made lightly - I have evidence: Drilled hole in the side of fridge - sealed around two thermistor wires with bubble wrap. Note that this is a working fridge with a slight auto defrost issue. The sensors - one is for the fridge in general and one for the load - no load at the moment so they are both just resting on the floor. The fridge controller - the display is telling me that the F(ridge) temperature is 6.5 and the L(oad) temperature is 6.0. (Warm because I just had the door open for a minute or two to take pictures. The controller display cycles and also shows the ambient and compressor temperatures and if the compressor is on or off. I modified the fridge and made the controller for a job about 10 years ago but now I just use the fridge to keep my cheese and butter cool and my mint sauce frozen. Drilling fridge walls is easy - usually very thin layer of metal or plastic sheet on each side of insulating foam. MKhttps://community.element14.com/technologies/sensor-technology/f/forum/57026/batteryless-temperature-sensorWed, 10 Jun 2026 09:13:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:a0c9cbf8-8472-45cc-9ccd-decbafcf2ae8obonesI have a fridge with two compartments, one for "fridge" temperature elements, and one for frozen foods. As it's showing its age, I want to monitor the temperature in both parts to be sure everything is still edible. For the fridge part, placing a zigbee sensor powered by a 2xAA or CR2032 battery is actually working fine, the battery is not too weakened by the 2°C temperature and the metallic body plates are not attenuating the signal too much. For the frozen foods parts, it's a bit more complex as temperatures go as low as -25°C. On top of that, because the thermostat is is in the fridge part, it happened in the past that the compressor never turned on because the temperature in the garage where it is located reached 4°C, effectively within the thermostat set temperature. As a result, I wanted to both have a quick way to check the current temperature, while having a history of said temperatures and to get this, I installed a zigbee sensor with a wired temperature probe like this: This works fine but the probe cable is quite thick (3mm) leading to air leakage at the location where the cable is getting through the door seal. Using a small scalpel, I was able to strip the outer insulation to get access to the three inner cables which are way thinner, hoping this would restore the seal effectiveness. Sadly, while this is better, this is still not enough, ice is building up inside, starting along the three cables as can be seen here: I had removed most of it two days before taking this picture and it's already back. So now, I'm trying to figure out an alternative for this and NFC/RFID came to mind as this would allow to get a sensor without batteries getting frozen inside the compartment, thus not requiring any wire to get into it and thus no longer interfering with the seal function. With the appropriate search terms, I stumbled across this reference design from TI: https://www.ti.com/tool/TIDM-RF430-TEMPSENSE But this gets me even more questions: What cost for creating this board? What tool to program the MCU? and what cost for this tool? What to use to read back the temperature? I have RPI Pico W or ESP32 at hand for the wifi communication. Would reading work through the metal sides of the fridge? Would this work if the sensor is at 90° with respect to the reader? For the last question, this stems from the fact that if question 4 answer is "no", then the RF waves would need to work through the 1/2 cm gap left by the compressed seal when the door is closed, as seen here: From what I grasped reading various articles, the longer the distance between the RFID tag and the reader, the larger the reader's antenna would need to be. I even saw 60cm diameter antennas, which, well, won't fit here at all. Do you think this RFID/NFC tag idea is worth exploring? Or would you suggest an alternative like cold resistant batteries if that exists? Thanks for your insights.temperature sensorhttps://community.element14.com/technologies/sensor-technology/b/blog/posts/can-leds-influence-human-visual-performanceFri, 05 Jun 2026 16:06:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:d1ba86f3-46e2-4442-ab44-47dbdfcd3cdbCatwell(Image Credit: BrianPenny/ pixabay ) University College London (UCL) researchers looked into whether LED lights limited spectral range negatively affects vision . They compared LED office lighting with broader-spectrum incandescent lighting, with infrared wavelengths missing from most LEDs. They also discovered that participants experienced an improvement in mitochondrial ATP production in retinal cells when exposed to longer-wavelength red and near-infrared light. LEDs emit light between 350nm and 650nm, lacking infrared output. Daylight has an even broader spectrum that goes beyond 1500nm. The team says this missing long-wavelength component could impact mitochondrial activity in retinal cells. They suggest the spectral gap could lead to significant implications for office design, occupational health, and lighting engineering practices. Researchers previously stated that near-infrared and long-wavelength light could boost mitochondrial ATP production via interactions with cytochrome c oxidase. This had the potential to support retinal metabolism and help with vision. Meanwhile, the team argues that “when shorter wavelength exposure is dominant, as in LED lighting, mitochondrial function declines.” They also say that mitochondrial complex proteins are reduced and there is reduced ATP production.” To test their theory, the team brought in 22 office workers. While eleven participants worked under standard LED office lighting, the others used incandescent lamps under similar conditions. The incandescent lights generated a wider range, which includes infrared wavelengths that standard LEDs don’t emit. Each participant used the lamps for eight hours per day, spanning two weeks. After two weeks of incandescent light exposure, protan and tritan contrast thresholds decreased from baseline. This indicates improved contrast sensitivity that persisted for weeks. (Image Credit: Scientific reports ) The team assessed visual performance via color contrast sensitivity (CCS) testing before exposure. Two weeks and four weeks after the experiment ended, they used CCS again. Specifically, they measure protan and tritan contrast sensitivity that correspond to red-green and blue-yellow visual discrimination pathways. This measuring method determines how well a participant can detect fine color distinctions to reliably evaluate the retina’s functionality. Participants with the broader spectrum incandescent lighting showed a 25% average increase of protan and tritan in CCS. And those with the LED experienced no significant changes. Improvements remained for at least four weeks after exposure to the incandescent lighting. However, the results are not definitive. The study had a small sample size and used a narrow set of visual performance metrics rather than ophthalmological testing. Additionally, it focused on CCS without addressing visual acuity and long-term eye health. Further studies will likely be needed before these results drive changes to lighting standards or architectural engineering practices. Have a story tip? Message me here at element14.hmilightinghumanstudyledjobhttps://community.element14.com/technologies/sensor-technology/b/blog/posts/researchers-develop-tiny-memory-that-improves-as-it-shrinksTue, 12 May 2026 19:40:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:0c3e3a96-695e-4b45-95c0-d18cf4573b82CatwellRendering of the 25-nanometer wide FTJ developed by Science Tokyo. (Image Credit: Yutaka Majima of the Royal Society of Chemistry) Engineers at Science Tokyo developed a 25-nanometer-wide ferroelectric tunnel junction (FTJ) memory that improves performance while scaling downward. Despite its tiny size, it still outperforms larger types, challenging the assumption that miniaturization weakens resistance contrast in extremely thin memory components. This is a significant breakthrough as electronics demand smaller, denser, and more efficient memory. The team believes the technology could be used for low-power applications and could fit standard CMOS manufacturing. The 25nm memory has a titanium/titanium oxide (Ti/TiOx) top electrode, a 3 nm yttrium-doped hafnium oxide ferroelectric tunnel barrier, and a platinum bottom electrode integrated into a nanocrossbar structure. It works by reversing polarization within the ultrathin ferroelectric barrier to alter the electrostatic potential across the junction. This process changes how easily electrons quantum tunnel from one electrode to the other. Due to the ultra-thin barrier, the electron wavefunction passes through it rather than undergoing thermally activated transport. And slight polarization-induced changes in barrier height or width modify the tunneling probability. As a result, the device creates two resistance states (ON/OFF) representing digital data storage. Temperature-dependent switching and resistance hysteresis behavior in 3 nm-thick nanocrossbar FTJs. (Image Credit: Nanoscale ) During electrical testing, the smallest FTJ with a 26 x 24 nm 2 junction area achieved a tunneling electroresistance (TER) ratio surpassing 2.2 x 10 3 . This is higher than the 71 TER achieved by the 30 nm FTJs. The team also performed temperature-dependent transport measurements at 9 K and 300 K, demonstrating nearly temperature-independent conduction behavior in the resistance states. Current transport was therefore dominated by quantum tunneling instead of thermally activated leakage. In addition, the researchers observed asymmetric current scaling while the active junction area shrank from 42,000 nm 2 to 255 nm 2 . In this case, the OFF-state current decreased (scaling slope of 1.1) more rapidly compared to ON-state current (slope of 0.30). That indicates nanoscaling minimized conductive leakage pathways and grain-boundary effects. Doing so improved resistance contrast instead of worsening at smaller dimensions. Science Tokyo researchers believe this technology could be practical for future low-power nonvolatile memory. They also say the Ti/TiOx/Y-doped HfO2/Pt structure supports CMOS-oriented hafnium oxide processing, simplifying integration into semiconductor manufacturing processes. Plus, the fast resistance switching and extremely thin ferroelectric barrier make scaled FTJs a good choice for in-memory computing, neuromorphic computer architectures, and edge devices requiring lower power consumption and a reduced footprint. Have a story tip? Message me here at element14.researchnanoon_campusmemoryuniversitysensorinnovationhttps://community.element14.com/technologies/sensor-technology/m/managed-videos/151276Thu, 30 Apr 2026 22:43:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:d5626b20-583d-49cb-a1fa-5ab4fd90a54estantoSponsor: Arctic MX-7 Thermal Paste on Amazon https://geni.us/WbHJ In this tear-down of the Valve Steam Controller, we inspect its construction, build quality, disassembly steps, and repairability. We found the controller's overall assembly to be e...steam controller replace thumbstickvalve steam machinevalvecomputer hardwarevalve steam controller frame trackingvalve steam controller disassemblysteam controller repairgamersnexussteam controller replace analog stickgamers nexussteam controller tmr stickssteam controller tear downvalve steamsteam controller replace batteryvalve steam controllervalve steam framehttps://community.element14.com/technologies/sensor-technology/f/forum/56896/check-out-what-s-in-the-steam-controllerThu, 30 Apr 2026 22:43:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:68eee50c-1328-44fd-95f5-6fee60efccbcstantowww.youtube.com/watch Capacitive touch, fancy joysticks, buttons and touchpads. There's even an infrared LED. Valve went all out. I think the best part about it is that it's easily repairable. 7 torx screws and you're in!steam controllerteardownhttps://community.element14.com/technologies/sensor-technology/b/blog/posts/maker-develops-ram-in-backyard-shedWed, 29 Apr 2026 07:08:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:0f093df3-4589-4d9b-bab2-44610e7b96f8CatwellRAM. (Image Credit: PublicDomainPictures/ pixabay ) I’d love to upgrade to DDR5 ram someday, I was just looking at those prices. I think we all know, RAM prices are crazy high due to the AI demand soaking up the memory supply. And there may not be much relief anytime soon. That’s where Dr. Semiconductor steps in. He turned his backyard shed into a class 100 semiconductor cleanroom to make his own RAM. In the YouTube video , he shows us exactly how he pulled it off. Dr. Semiconductor starts his DRAM-making process by cutting silicon wafer chips from a large sheet into small pieces. He then grows a thin oxide layer in a high-temperature furnace, which keeps the silicon protected and isolated. According to reports, this oxide layer is around 330 nm thick. Afterward, he added an adhesive layer, baked it, and then added a photoresist film on the surface. After baking, the chips had a 1-micron-thick photosensitive surface. Then, he uses UV light through a mask to pattern the chip, shrinking it down with microscope magnification stages. Software also helped dry-etch transistor patterns onto the chip. This photolithography step is also used in chip manufacturing, and Dr. Semiconductor’s setup is much smaller. Once the pattern is exposed, he uses dimethyl sulfoxide to wash away unwanted photoresist. Doing so ensures precise openings remain, so later steps alter the silicon. He also forms transistor source and drain regions by doping the silicon with phosphorus and thermally annealing it. This enables the dopant to spread deeper into the material. His later steps involve layer etching, making contact holes, and spraying aluminum with a stencil to allow the tiny structures to conduct electricity and be tested. Complete structure of the homemade DRAM with the transistors, capacitors, and connections for the DRAM array. (Image Credit: Dr. Semiconductor ) The scale of this project is also noteworthy. All the DRAM cells are tiny, which means DIYers can’t test them out on machinery, as wires won’t be able to reach them. Instead, he uses micromanipulator probes. Dr. Semiconductor was happy enough with his DRAM chips, especially because the cells achieved a practical 12 pF capacitance. By the end of the video, he mentions that he will build on this DRAM project. His goal is to create an expanded memory cell array that connects to a PC. www.youtube.com/watch Have a story tip? Message me here at element14.rammakermanufacturingdiyembeddedclean roomhttps://community.element14.com/technologies/sensor-technology/m/managed-videos/151245Wed, 29 Apr 2026 07:08:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:2c1cfb44-210a-4f9e-947a-95efb7cafcd9CatwellThanks for the support! https://www.patreon.com/cw/DrSemiconductor Shoutout to Projects in Flight for a helpful reference on the doping: https://www.youtube.com/@projectsinflight Background music includes RuneScape music used under Jagex's Fan Con...