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Відкритий ветеранський турнір з довгих нард «Воїн Світла» в КПІ ім. Ігоря Сікорського
26 листопада 2025 року у смартукритті CLUST Space в Науково-технічній бібліотеці ім. Г. І. Денисенка (Бібліотека КПІ ім. Ігоря Сікорського) відбувся перший Відкритий ветеранський турнір з довгих нард «Воїн Світла» – подія для соціальної інтеграції і підтримки ветеранів, їх взаємодії між собою та з університетською спільнотою.
Nimy gains CSIRO Kick-Start program funding for gallium exploration
STMicroelectronics’ new GaN ICs platform for motion control boosts appliance energy ratings
STMicroelectronics unveiled new smart power components that let home appliances and industrial drives leverage the latest GaN (gallium-nitride) technology to boost energy efficiency, increase performance, and save cost.
GaN power adapters and chargers available in the market can handle enough power for laptops and USB-C fast charging to achieve extremely high efficiency to meet stringent incoming eco-design norms. ST’s latest GaN ICs now make this technology applicable to motor drives for products like washing machines, hairdryers, power tools, and factory automation.
“Our new GaNSPIN system-in-package platform unleashes wide-bandgap efficiency gains in motion-control applications by introducing special features that optimize system performance and safeguard reliability,” said Domenico Arrigo, General Manager, Application Specific Products Division, STMicroelectronics. “The new devices enable future generations of appliances to achieve higher rotational speed for improved performance, with smaller and lower-cost control modules, lightweight form factors, and improved energy ratings.”
The first members of ST’s new family, the GANSPIN611 and GANSPIN612, can power motors of up to 400 Watts including domestic and industrial compressors, pumps, fans, and servo drives. Pin compatibility between the two devices ensures designs are easily scalable. GANSPIN611 is in production now, in a 9mm x 9mm thermally enhanced QFN package, from $4.44.
Technical notes on GaNSPIN drivers:
In the new GaNSPIN system-in-package, unlike in general-purpose GaN drivers, the driver controls turn-on and turn-off times in hard switching to relieve stress on the motor windings and minimize electromagnetic noise. The nominal slew rate (dV/dt) of 10V/ns preserves reliability and eases compliance with electromagnetic compatibility (EMC) regulations such as the EU EMC directive. Designers can adjust the turn-on dV/dt of both GaN drivers to fine-tune the switching performance according to the motor characteristics.
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Inside the battery: A quick look at internal resistance

Ever wondered why a battery that reads full voltage still struggles to power your device? The answer often lies in its internal resistance. This hidden factor affects how efficiently a battery delivers current, especially under load.
In this post, we will briefly examine the basics of internal resistance—and why it’s a critical factor in real-world performance, from handheld flashlights to high-power EV drivetrains.
What’s internal resistance and why it matters
Every battery has some resistance to the flow of current within itself—this is called internal resistance. It’s not a design flaw, but a natural consequence of the materials and construction. The electrolyte, electrodes, and even the connectors all contribute to it.
Internal resistance causes voltage to drop when the battery delivers current. The higher the current draw, the more noticeable the drop. That is why a battery might read 1.5 V at rest but dip below 1.2 V under load—and why devices sometimes shut off even when the battery seems “full.”
Here is what affects it:
- Battery type: Alkaline, lithium-ion, and NiMH cells all have different internal resistances.
- Age and usage: Resistance increases as the battery wears out.
- Temperature: Cold conditions raise resistance, reducing performance.
- State of charge: A nearly empty battery often shows higher resistance.
Building on that, internal resistance gradually increases as batteries age. This rise is driven by chemical wear, electrode degradation, and the buildup of reaction byproducts. As resistance climbs, the battery becomes less efficient, delivers less current, and shows more voltage drop under load—even when the resting voltage still looks healthy.
Digging a little deeper—focusing on functional behavior under load—internal resistance is not just a single value; it’s often split into two components. Ohmic resistance comes from the physical parts of the battery, like the electrodes and electrolyte, and tends to stay relatively stable.
Polarization resistance, on the other hand, reflects how the battery’s chemical reactions respond to current flow. It’s more dynamic, shifting with temperature, charge level, and discharge rate. Together, these resistances shape how a battery performs under load, which is why two batteries with identical voltage readings might behave very differently in real-world use.
Internal resistance in practice
Internal resistance is a key factor in determining how much current a battery can deliver. When internal resistance is low, the battery can supply a large current. But if the resistance is high, the current it can provide drops significantly. Also, higher the internal resistance, the greater the energy loss—this loss manifests as heat. That heat not only wastes energy but also accelerates the battery’s degradation over time.
The figure below illustrates a simplified electrical model of a battery. Ideally, internal resistance would be zero, enabling maximum current flow without energy loss. In practice, however, internal resistance is always present and affects performance.

Figure 1 Illustration of a battery’s internal configuration highlights the presence of internal resistance. Source: Author
Here is a quick side note regarding resistance breakdown. Focusing on material-level transport mechanisms, battery internal resistance comprises two primary contributors: electronic resistance, driven by electron flow through conductive paths, and ionic resistance, governed by ion transport within the electrolyte.
The total effective resistance reflects their combined influence, along with interfacial and contact resistances. Understanding this layered structure is key to diagnosing performance losses and carrying out design improvements.
As observed nowadays, elevated internal resistance in EV batteries hampers performance by increasing heat generation during acceleration and fast charging, ultimately reducing driving range and accelerating cell degradation.
Fortunately, several techniques are available for measuring a battery’s internal resistance, each suited to different use cases and levels of diagnostic depth. Common methods include direct current internal resistance (DCIR), alternating current internal resistance (ACIR), and electrochemical impedance spectroscopy (EIS).
And there is a two-tier variation of the standard DCIR technique, which applies two sequential discharge loads with distinct current levels and durations. The battery is first discharged at a low current for several seconds, followed by a higher current for a shorter interval. Resistance values are calculated using Ohm’s law, based on the voltage drops observed during each load phase.
Analyzing the voltage response under these conditions can reveal more nuanced resistive behavior, particularly under dynamic loads. However, the results remain strictly ohmic and do not provide direct information about the battery’s state of charge (SoC) or capacity.
Many branded battery testers, such as some product series from Hioki, apply a constant AC current at a measurement frequency of 1 kHz and determine the battery’s internal resistance by measuring the resulting voltage with an AC voltmeter (AC four-terminal method).

Figure 2 The Hioki BT3554-50 employs AC-IR method to achieve high-precision internal resistance measurement. Source: Hioki
The 1,000-hertz (1 kHz) ohm test is a widely used method for measuring internal resistance. In this approach, a small 1-kHz AC signal is applied to the battery, and resistance is calculated using Ohm’s law based on the resulting voltage-to-current ratio.
It’s important to note that AC and DC methods often yield different resistance values due to the battery’s reactive components. Both readings are valid—AC impedance primarily reflects the instantaneous ohmic resistance, while DC measurements capture additional effects such as charge transfer and diffusion.
Notably, the DC load method remains one of the most enduring—and nostalgically favored—approaches for measuring a battery’s internal resistance. Despite the rise of impedance spectroscopy and other advanced techniques, its simplicity and hands-on familiarity continue to resonate with seasoned engineers.
It involves briefly applying a load—typically for a second or longer—while measuring the voltage drop between the open-circuit voltage and the loaded voltage. The internal resistance is then calculated using Ohm’s law by dividing the voltage drop by the applied current.
A quick calculation: To estimate a battery’s internal resistance, you can use a simple voltage-drop method when the open-circuit voltage, loaded voltage, and current draw are known. For example, if a battery reads 9.6 V with no load and drops to 9.4 V under a 100-mA load:
Internal resistance = 9.6 V-9.4 V/0.1 A = 2 Ω
This method is especially useful in field diagnostics, where direct resistance measurements may not be practical, but voltage readings are easily obtained.
In simplified terms, internal resistance can be estimated using several proven techniques. However, the results are influenced by the test method, measurement parameters, and environmental conditions. Therefore, internal resistance should be viewed as a general diagnostic indicator—not a precise predictor of voltage drop in any specific application.
Bonus blueprint: A closing hardware pointer
For internal resistance testing, consider the adaptable e-load concept shown below. It forms a simple, reliable current sink for controlled battery discharge, offering a practical starting point for further refinement. As you know, the DC load test method allows an electronic load to estimate a battery’s internal resistance by observing the voltage drop during a controlled current draw.

Figure 3 The blueprint presents an electronic load concept tailored for internal resistance measurement, pairing a low-RDS(on) MOSFET with a precision load resistor to form a controlled current sink. Source: Author
Now it’s your turn to build, tweak, and test. If you have got refinements, field results, or alternate load strategies, share them in the comments. Let us keep the circuit conversation flowing.
T. K. Hareendran is a self-taught electronics enthusiast with a strong passion for innovative circuit design and hands-on technology. He develops both experimental and practical electronic projects, documenting and sharing his work to support fellow tinkerers and learners. Beyond the workbench, he dedicates time to technical writing and hardware evaluations to contribute meaningfully to the maker community.
Related Content
- All About Batteries
- What Causes Batteries to Fail?
- Power Consumption and Battery Life Analysis
- Resistivity is the key to measuring electrical resistance
- Cell balancing maximizes the capacity of multi-cell batteries
The post Inside the battery: A quick look at internal resistance appeared first on EDN.
PCB Easter eggs on Zebra printers
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Workbench and work area.
| | I can never keep this clean, its one thing after another. [link] [comments] |
Quantum Critical Metals and Nusano collaborate on developing and refining critical minerals in North America
Quantum Critical Metals and Nusano collaborate on developing and refining critical minerals in North America
Thank God they included the High Power Imported Heater with my new soldering iron.
| | It would've been a shame if it was domestic [link] [comments] |
Silanna UV’s 235nm far-UVC LEDs inactivate multiple H5N1 avian ’flu virus strains
Silanna UV’s 235nm far-UVC LEDs inactivate multiple H5N1 avian ’flu virus strains
КПІ. Вулиця Михайла Брайчевського
Ім'я Михайла Брайчевського – українського історика, археолога й громадського діяча – носить вулиця в студмістечку КПІ. Наприкінці 2022-го таке рішення ухвалила Київська міська рада з метою деколонізації столичної топоніміки.
My Workbench Hobby
| | submitted by /u/BetimSec [link] [comments] |
My closet workbench
| | Just cleaned up and reorganized my small bench setup yesterday and thought I could get some critiques on what might be missing. not shown is a HP 8592 Spectrum analyzer and HP 54615B 500 MHz OScope. [link] [comments] |
NB-IoT module adds built-in geolocation capabilities

The ST87M01-1301 NB-IoT wireless module from ST provides narrowband cellular connectivity along with both GNSS and Wi-Fi–based positioning for outdoor and indoor geolocation. Its integrated GNSS receiver enables precise location tracking using GPS constellations, while the Wi-Fi positioning engine delivers fast, low-power indoor location services by scanning nearby 802.11b access points and leveraging third-party geocoding providers.

As the latest member of the ST87M01 series of NB-IoT (LTE Cat NB2) industrial modules, this variant supports multi-frequency bands with extended multi-regional coverage. Its compact, low-power design makes it well suited for smart IoT applications such as asset tracking, environmental monitoring, smart metering, and remote healthcare. A 10.6×12.8-mm, 51-pin LGA package further enables miniaturization in space-constrained designs.
ST provides an evaluation kit that includes a ready-to-use Conexa IoT SIM card and two SMA antennas, helping developers quickly prototype and validate NB-IoT connectivity in real-world conditions. This is supported by an expanding ecosystem featuring the Easy-Connect software library and design examples.
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Boost controller powers brighter automotive displays

A 60-V boost controller from Diodes, the AL3069Q packs four 80-V current-sink channels for driving LED backlights in automotive displays. Its adaptive boost-voltage control allows operation from a 4.5-V to 60-V input range—covering common automotive power rails at 12 V, 24 V, and 48 V—and its switching frequency is adjustable from 100 kHz to 1 MHz.

The AL3069Q’s four current-sink channels are set using an external resistor, providing typical ±0.5% current matching between channels and devices to ensure uniform brightness across the display. Each channel delivers 250 mA continuous or up to 400 mA pulsed, enabling support for a range of display sizes and LED panels up to 32-inch diagonal, such as those used in infotainment systems, instrument clusters, and head-up displays. PWM-to-analog dimming, with a minimum duty cycle of 1/5000 at 100 Hz, improves brightness control while minimizing LED color shift.
Diode’s AL3069Q offers robust protection and fault diagnostics, including cycle-by-cycle current limit, soft-start, UVLO, programmable OVP, OTP, and LED-open/-short detection. Additional safeguards cover sense resistor, Schottky diode, inductor, and VOUT faults, with a dedicated pin to signal any fault condition.
The automotive-compliant controller costs $0.54 each in 1000-unit quantities.
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Hybrid device elevates high-energy surge protection

TDK’s G series integrates a metal oxide varistor and a gas discharge tube into a single device to provide enhanced surge protection. The two elements are connected in series, combining the strengths of both technologies to deliver greater protection than either component can offer on its own. This hybrid configuration also reduces leakage current to virtually zero, helping extend the overall lifetime of the device.

The G series comprises two leaded variants—the G14 and G20—with disk diameters of 14 mm and 20 mm, respectively. G14 models support AC operating voltages from 50 V to 680 V, while G20 versions extend this range to 750 V. They can handle maximum surge currents of 6,000 A (G14) and 10,000 A (G20) for a single 8/20-µs pulse, and absorb up to 200 J (G14) or 490 J (G20) of energy.
Operating over a temperature range of –40 °C to +105 °C, the G series is suitable for use in power supplies, chargers, appliances, smart metering, communication systems, and surge protection devices. Integrating both protection elements into a single, epoxy-coated 2-pin package simplifies design and reduces board space compared to using discrete components.
To access the datasheets for the G14 series (ordering code B72214G) and the G20 series (B72220G), click here.
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Power supplies enable precise DC testing

R&S has launched the NGT3600 series of DC power supplies, delivering up to 3.6 kW for a wide range of test and measurement applications. This versatile line provides clean, stable power with low voltage and current ripple and noise. With a resolution of 100 µA for current and 1 mV for voltage, as well as adjustable output voltages up to 80 V, the supplies offer both precision and flexibility.

The dual-channel NGT3622 combines two fully independent 1800-W outputs in a single compact instrument. Its channels can be connected in series or parallel, allowing either the voltage or the current to be doubled. For applications requiring even more power, up to three units can be linked to provide as much as 480 V or 300 A across six channels. The NGT3622 supports current and voltage testing under load, efficiency measurements, and thermal characterization of components such as DC/DC converters, power supplies, motors, and semiconductors.
Engineers can use the NGT3600 series to test high-current prototypes such as base stations, validate MPPT algorithms for solar inverters, and evaluate charging-station designs. In the automotive sector, the series supports the transition to 48-V on-board networks by simulating these networks and powering communication systems, sensors, and control units during testing.
All models in the NGT3600 series are directly rack-mountable with no adapter required. They will be available beginning January 13, 2026, from R&S and selected distribution partners. For more information, click here.
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Space-ready Ethernet PHYs achieve QML Class P

Microchip’s two radiation-tolerant Ethernet PHY transceivers are the company’s first devices to earn QML Class P/ESCC 9000P qualification. The single-port VSC8541RT and quad-port VSC8574RT support data rates up to 1 Gbps, enabling dependable data links in mission-critical space applications.

Achieving QML Class P/ESCC 9000P certification involves rigorous testing—such as Total Ionizing Dose (TID) and Single Event Effects (SEE) assessments—to verify that devices tolerate the harsh radiation conditions of space. The certification also ensures long-term availability, traceability, and consistent performance.
The VSC8541RT and VSC8574RT withstand 100 krad(Si) TID and show no single-event latch-up at LET levels below 78 MeV·cm²/mg at 125 °C. The VSC8541RT integrates a single Ethernet copper port supporting MII, RMII, RGMII, and GMII MAC interfaces, while the VSC8574RT includes four dual-media copper/fiber ports with SGMII and QSGMII MAC interfaces. Their low power consumption and wide operating temperature ranges make them well-suited for missions where thermal constraints and power efficiency are key design considerations.
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