Збирач потоків

КПІ ім. Ігоря Сікорського, БО БФ «КОЛО» та Beredskapslyftet реалізують міжнародний проєкт «Ерготерапія без кордонів» в Україні kpi пн, 05/25/2026 - 16:11

While its vehicle battery resurrection skills are uncertain at best, this device also offers other useful abilities.

Two-plus years back, within my teardown of my PowerStation PSX3:

which I described at the time as being:

…(among other things) a portable recharger and jump-starter of vehicles’ cells. It’s also a portable tire inflater. And it’s an emergency light and USB power source, too…

I took advantage of the opportunity to also editorially “rip” into three newer solid-state and Li-ion battery-based versions of the same concept:

I tried three of these widgets, one claiming to deliver 1200 A of “peak” cranking juice:

Another spec’ing 1500 A:

And a third that promised to deliver 2000 A:

They all promptly went back to Amazon as full-refund returns. Now granted, if someone had left their interior dome light on too long and the battery was drained too low to successfully turn over the engine but still had some “life” one of these might suffice…And I’ll grant them one other thing: they’re certainly small and light.

But 2000 A of cranking current? Or even 1500 A? Mebbe for a fraction of a second, the time necessary to drain an intermediary capacitor, but not long enough to resurrect a significantly drained battery. Therefore, the quotes I put around the word “peak” earlier. Such products exemplify the well-worn saying, “mileage may vary”. Give me an old-school lead acid battery instead, any day!

Regarding my “They all promptly went back to Amazon as full-refund returns” comment, while that was my original intent, I didn’t end up fully actualizing it. The “1200 A” and “1500 A” variants indeed did get shipped back to the retailer. But, curiosity-motivated, I decided to keep the “2000 A” model, Spanarci’s ZETA2000, around if for no other reason than as a future teardown candidate.

Calling Cupertino…

That future is today. As usual, I’ll start with some outer box shots (sparing you the blank sides), as usual accompanied by a 0.75″ (19.1 mm) diameter U.S. penny for size comparison purposes:

Although my skepticism about the device’s jump-starting potential is already obvious at this early point in the writeup, I was admittedly impressed by the aesthetics and overall packaging of the product. Dare I even say it was Apple-reminiscent?

The cleverly labeled “Never Say Never” envelope, reminiscent (at least to me) of SpaceX’s three autonomous spaceport drone ships (i.e., floating rocket booster landing pads), “Of Course I Still Love You”, “Just Read the Instructions” and “A Shortfall of Gravitas”, contains literature bits:

Gee, I wonder what’s inside this translucent plastic sleeve?

To stretch the suspense, I’ll temporarily set it aside and investigate the lower box level instead:

Within is the to-vehicle battery cable harness, conveniently accompanied by USB-A-to-USB-C and USB-C-to-USB-C cables useful both for recharging the device’s internal battery pack and for powering other connected devices. Hold that thought:

Here’s the male connector at the end of the cable harness…

Burlesque finale

And here’s what it plugs into…

at out dissection patient, finally unswathed for its reveal. Top first:

Here’s the front:

Underneath the rubberized flap labeled “INPUT OUTPUT” at the right end are, likely unsurprisingly, first a bidirectional USB-C PD 30-W connector used for both device charging and for charging/powering another tethered device, such as a smartphone. The other, USB-A in form factor, is unidirectional (output-only) for similar tethered device “juicing” purposes.

Onward. Left side:

Rear; under this flap, cryptically (ha!) labeled “JUMPER CABLE” is the battery-cable harness connector you saw earlier:

And what the heck is that on the right side? A multi-LED strip, creating a 300-lumen four-mode (50% and 100% brightness stable, and both SOS and strobe pattern) flashlight, that’s what it is!

Last but not least, here’s the bottom view:

accompanied by a zoom-in of the specs:

Before opening ‘er up, I’ll note a few other feature set nuances. Like the conventional (i.e., AC-powered) solid-state charger that I tore down earlier this month, it supports various safety features such as short-circuit and “reverse” protection:

That said, there’s also “FORCE” support for dead cells and daring users:

The teardown’s the thing…

And now, let’s dive inside. Zoom back out on that earlier bottom overview shot and you’ll discern eight round rubber pieces, one in each corner and two more both at top and bottom:

I bet you can guess what comes next:

Eureka! Screw heads (trust me, they’re there, deep inside the recessed dimness)!

And what comes after that, dear readers? You got it right:

Dare I draw another analogy to Apple craftsmanship? Seriously, I’m impressed with the neatness and overall robustness of the insides, too!

Here’s the inside of the case topside:

…wherein I’ll detail the insides of the thing

And the overview that’s likely of greater interest to all of you!

Dominating the landscape, aside from the display, that is:

is the largest IC on this side, at center (horizontally) and toward the bottom (vertically). It’s Holtek’s HT67F489 8-bit RISC microcontroller, unsurprisingly with an integrated LCD controller and also containing (among other things) 8 Kwords of flash memory (4 Kwords on the more modest HT67F488 sibling, which the datasheet informs me (PDF) has been discontinued, anyway), 256 bytes of RAM and 64 bytes of EEPROM (none on the HT67F488). Also note two mode-select switches at far right, which mate to rubberized front panel buttons.

Let’s get that PCB out, shall we? Three screws hold it in place:

Guess what comes next?

In addition to noticing the now-absent screws (and their previously visible heads) in the next photo, I’d also like to draw your attention to the smaller but still-square IC to the right of the aforementioned HT67F489. It’s Southchip Semiconductor Technology’s SC2001 USB-PD controller. Given what you already know about the capability of the USB-C connector on the front of the device, this chip’s presence and functions shouldn’t be a surprise.

Here goes nothing:

My, what a big power source you have…

At left is the 44.4 Wh lithium polymer battery pack:

To its right is a beefy Sanyi Seiko SEV8-P-112DM 4-pin high-power relay:

soldered to a mini-PCB:

And the remainder of the compartment mostly consists of a bunch of now-disconnected wire harnesses:

The destination of one of them was, I admit with no shortage of chagrin, initially identity-baffling to me, until I pulled it out. See that gold-colored half-oval to the far right?

Oh yeah. The LEDs. Duh on me:

Underneath that large green region on the PCB underside is, as far as I can feel, nothing notable save for mounting-bracket sites and solder points related to the LCD on the other side:

The PCB-mounted speaker in one corner delivers a loud “beep” tone if, for example, you’ve got your to-battery connections reversed:

The one next to it is “just” an inductor (L1 is peeking out from the PCB under the white glue):

It, along with the rest of the components surrounding it (and some of those on the other side), implements a largely unmemorable power management subsystem.

In closing, I’ll share a side view of the USB-C and USB-A connectors; since the PCB is upside-down from its normal operating orientation, so are they:

…the better to incinerate you with, my dear

With that, I’ll close for today. Speaking of closing, I’ll keep the device disassembled for a while post-publication of this teardown. Then I’ll carefully reassemble it in the hopes of resurrecting it. If you smell smoke, see flame, or hear a loud “boom”, you’ll know my efforts didn’t succeed.

—Brian Dipert is the associate editor, as well as a contributing editor, at EDN.

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• Dead lead-acid batteries: Desulfation-resurrection opportunities?

The post Portable jump starters: A dubious primary use case, but not a total waste appeared first on EDN.

КПІ ім. Ігоря Сікорського — на «Фестивалі кар’єри» на ВДНГ kpi пн, 05/25/2026 - 12:33

Gas discharge tubes (GDTs) harness the physics of controlled sparks to provide reliable surge protection, making them a fundamental safeguard for modern electronic circuits.

They are deceptively simple devices that rely on ionized gas to tame the chaos of voltage surges. When a transient spike threatens sensitive circuitry, a GDT responds with a controlled spark, safely channeling excess energy away from the system.

Compact, rugged, and reliable, these components have become indispensable in applications ranging from telecom lines to industrial equipment. In essence, GDTs turn sparks into protection, making them a cornerstone in the engineer’s surge-defense toolkit.

It’s worth noting that GDTs are sometimes referred to as plasma arrestors. The two names describe the same device; a sealed tube filled with inert gas that forms a plasma arc when voltage exceeds its breakdown threshold. “GDT” is the term most often used in engineering literature and standards, while “gas plasma arrestor” tends to appear in catalogs or marketing to highlight the plasma discharge mechanism.

Inside the spark: How GDTs work

From the first spark to the final safeguard, gas discharge tubes show how even the simplest devices can deliver powerful protection where it matters most. To understand why, let us take a closer look at how they work.

At the heart of a GDT is a sealed chamber filled with inert gas such as neon or argon. Two electrodes face each other across a small gap inside this chamber. Under normal operating conditions, the gas is non-conductive, and the tube behaves like an open circuit. But when a voltage surge pushes the potential across the electrodes beyond the breakdown threshold, the gas ionizes. This ionization triggers a plasma discharge—controlled spark—that suddenly makes the tube conductive.

The plasma arc provides a low-resistance path, diverting the surge current safely away from sensitive components. Once the surge subsides and the voltage drops below the sustaining level, the plasma extinguishes, and the tube returns to its insulating state. This simple cycle—breakdown, conduction, recovery—is what makes GDTs both rugged and reliable in protecting circuits against transient overvoltages.

Figure 1 A medium-duty 2-electrode gas discharge tube safeguards telecommunications, industrial, and consumer electronics from voltage surges. Source: Bourns

Shared sparks, shared protection

Building on the fundamentals, the next nuance lies in how protection is applied across conductors. A two-lead GDT serves as a straightforward single-path protector, perfect for shunting individual DC rails or coaxial cables to ground. But when you place two separate two-lead tubes across a data pair, they will never fire at precisely the same instant, leaving a harmful “transverse voltage” between the lines.

A three-lead GDT solves this by enclosing both conductors in a common gas chamber. The moment one side ionizes, the entire tube triggers, discharging both lines to ground simultaneously. This synchronized action delivers the balanced protection that sensitive telecommunications and differential data circuits demand.

Figure 2 A 3-lead GDT ensures simultaneous crowbar action across differential lines, preventing unbalanced residual voltages during a surge event. Source: Littelfuse

It’s important to note at this point that standard GDTs are commonly available in both 2- and 3-electrode configurations, whereas high-voltage variants are primarily limited to 2-electrode designs with select 3-electrode exceptions. While 2-electrode devices are typically deployed for either line-to-ground or line-to-line protection, a 3-electrode GDT provides the advantage of addressing both protection paths within a single component.

Practical implementation of GDTs

When selecting a GDT for a specific application, the primary objective is to ensure the device remains inactive during normal operation while reacting instantaneously to overvoltage transients. This requires careful evaluation of key electrical parameters, starting with the DC spark-over voltage. To prevent “nuisance” triggering, the GDT’s minimum breakdown rating should typically be 1.2 to 1.5 times the peak operating voltage of the system.

Furthermore, because GDTs are “crowbar” devices, engineers must account for follow-on current, the current that continues to flow through the ionized gas after the surge has passed. If the system’s power source can sustain this arc, additional current-limiting components or a coordinated circuit design may be necessary to ensure the GDT successfully resets to its high-impedance state once the transient is cleared.

However, follow-on current is often absent from GDT datasheets because it’s not a fixed constant of the device, but rather a system-dependent behavior. A GDT is essentially a triggered short circuit; once ionized, its resistance drops so low that the resulting current is determined almost entirely by your power supply’s voltage and internal impedance.

While manufacturers provide the arc voltage and the glow-to-arc transition current, they cannot predict your specific source’s capacity to sustain that arc. Consequently, engineers must use those parameters to calculate the “holdover” risk themselves, often necessitating components like metal oxide varistor (MOV) to effectively “starve” the arc and allow the GDT to reset.

To round out the technical profile, several other parameters define a GDT’s performance and longevity. Maximum impulse spark-over voltage is critical, as it indicates the highest voltage level the device allows during a fast-rising surge before it triggers. To gauge durability, engineers look at nominal impulse discharge current, which is the peak surge current the GDT can survive for a set number of pulses, and alternating discharge current, which measures its ability to handle sustained AC faults.

Additionally, maximum capacitance must be minimal to ensure signal integrity in high-frequency lines, while minimum insulation resistance ensures the GDT remains electrically “invisible” until a surge occurs.

Figure 3 Plot illustrates the GDT voltage breakdown characteristic. Source: Author

As a worthy take on paper, the GDT’s protective behavior is defined by its transition through distinct electrical phases, captured sequentially in Figure 3. The process initiates with the sparkover voltage, the exact point where the internal gas ionizes and becomes conductive. Immediately following this breakdown, the voltage falls to a relatively stable plateau known as the glow region, where current flows but remains limited.

As the surge energy intensifies, the device undergoes the rapid glow to arc transition, the critical threshold where the discharge collapses into a highly conductive plasma. This leads immediately to the arc voltage, the final “crowbar” state where the voltage drop plummets to its absolute lowest point. Identifying this transition sequence is vital, as the low arc voltage is precisely what triggers the risk of sustained follow-on current from the system’s power source.

GDTs are often evaluated against IEC 61000‑4‑5, the international surge immunity standard, because their protective behavior directly addresses the transient overvoltages defined by this test. The standard specifies surge waveforms—most notably the 1.2/50 µs voltage impulse and the 8/20 µs current impulse—to replicate lightning‑induced or switching transients. In these scenarios, GDTs act as frontline protectors, clamping and diverting surge energy away from sensitive equipment to ensure compliance and resilience.

Bonus insight: How to test a GDT surge arrestor

Have you ever wondered how to verify whether a GDT surge arrestor is still healthy and ready to protect against lightning, static, or electromagnetic pulse (EMP) events? An EMP is a sudden burst of electromagnetic energy—often from lightning strikes, solar storms, or even man-made sources—that can damage sensitive electronics. The only definitive way to confirm a GDT’s readiness is to make the device “fire”.

The most reliable approach is a DC high-voltage ramp test, performed with a power supply or a megohmmeter. Because a GDT behaves like an open circuit under normal conditions, you gradually increase the DC voltage across its terminals until it reaches the rated breakdown point. To ensure safety and prevent excessive current once the tube fires, a series resistor should always be included in the test circuit. This resistor limits the surge current, protects the power supply, and prevents overstressing the GDT during repeated tests.

Sparking applications, igniting ideas

Gas discharge tubes prove their worth across a wide spectrum of systems. In telecommunications, they safeguard MDF modules, xDSL equipment, RF systems, antennas, and base stations. In industrial and consumer electronics, they protect power supplies, surge protectors, alarm systems, and even irrigation systems.

Positioned in front of and in parallel with sensitive lines—power, communication, signal, and data transmission—GDTs shield equipment from transient surges caused by lightning strikes or switching operations. Under normal conditions they remain invisible to the signal, but when an overvoltage surge arrives, they switch to a low-impedance state and divert the energy safely away from the circuitry.

These sparks of protection are more than circuit defense; they are design opportunities. For makers and engineers, the challenge is to take this proven sequence from sparkover to arc and reimagine it in your own projects. Every surge control is a chance to build systems that are not only safer but smarter. So let the sparks inspire you: experiment boldly, refine relentlessly, and turn protective theory into resilient innovation.

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

• Power-Back Surge Protection Circuit
• Overvoltage-protection circuit saves the day
• Robust overvoltage protection in high-density electronics
• How to prevent overvoltage conditions during prototyping
• Gas Discharge Tubes: Old Protection in a New Bottle–Literally

The post Gas discharge tubes (GDTs): From sparks to circuit protection appeared first on EDN.

Just got these in their original packaging yesterday! submitted by /u/Electrical_Car_6067 [link] [comments]