IKEA Koppla USB Supply Clears Teardown With Robust Mains Isolation

bigclivedotcom

A teardown reveals the budget adapter incorporates multi-layer transformer shielding, inrush protection, and a molded plastic isolation blade that eliminate shock hazards common in low-cost chargers.

AI-assisted summary of Teardown of an IKEA Koppla USB power supply. — original source. Check the original for full context.

Source published: 2016-04-08

Key ideas

Destructive teardown of the IKEA Koppla 3.4A USB power supply confirms it adheres to rigorous safety standards, contrasting sharply with dangerous fakes that can have as little as 2 mm of isolation between mains and low-voltage rails. (0:00)
Leakage current on the double-insulated IKEA Koppla measured at 64 µA, well below the ~100 µA observed on an unearthed genuine Apple charger. (2:30)
Internal dissection reveals complex safety engineering, including an interleaved split-primary transformer, a grounded trifilar electrostatic screen, and double-insulated secondary wire. (12:48)
The enclosure and PCB feature robust physical isolation, combining a routed board slot with an integrated molded plastic barrier blade and spark gaps rated to ~10 kV. (10:27)

Detailed notes

## Background Published on YouTube by bigclivedotcom on April 8, 2016, this teardown video examines an IKEA Koppla multi-port USB power supply. Big Clive takes the unit apart to evaluate its electrical safety, galvanic isolation, and internal transformer construction in line with his general recommendation to use prominent brand chargers.

## TL;DR Big Clive disassembles an IKEA Koppla 3-port USB power supply to evaluate its build quality and safety compared to dangerous counterfeit chargers. After measuring a compliant 64 µA leakage current and cracking the welded case, he inspects the PCB's robust input protection, inrush thermistor, common-mode filtering, and auto-detect charging ICs. He then completely unwinds the high-frequency transformer, uncovering a well-designed interleaved sandwich construction with electrostatic Faraday shielding and thick secondary wire insulation. Finding strong thermal planning, milled PCB isolation slots, and an internal plastic barrier blade, Clive concludes the charger is exceptionally well-engineered and safe to recommend.

## Atmosphere & style The presentation is calm, methodical, and delightfully geeky, driven by Clive's characteristic Scottish lilt, gentle dry humor, and hands-on bench curiosity. While destructive teardowns of functioning equipment carry a lighthearted sense of 'criminal' guilt, the video treats safety hazards with genuine gravity, contrasting the Koppla's solid construction against terrifying cheap clones. Watching it feels like looking over the shoulder of an expert tinkerer patiently peeling back layers of magnet wire and lacquer to reveal the hidden craftsmanship inside an ordinary household object.

## Bulletin - [00:00](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=0s) Destructive teardown of the IKEA Koppla 3.4A USB power supply confirms it adheres to rigorous safety standards, contrasting sharply with dangerous fakes that can have as little as 2 mm of isolation between mains and low-voltage rails. - [02:30](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=150s) Leakage current on the double-insulated IKEA Koppla measured at 64 µA, well below the ~100 µA observed on an unearthed genuine Apple charger. - [12:48](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=768s) Internal dissection reveals complex safety engineering, including an interleaved split-primary transformer, a grounded trifilar electrostatic screen, and double-insulated secondary wire. - [10:27](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=627s) The enclosure and PCB feature robust physical isolation, combining a routed board slot with an integrated molded plastic barrier blade and spark gaps rated to ~10 kV.

## Key takeaways - [00:00](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=0s) Counterfeit and bargain chargers present severe hazards, frequently lacking galvanic isolation or routing live mains tracks within millimeters of low-voltage DC rails. - [02:30](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=150s) Genuine Apple chargers can exhibit around 100 µA of leakage current due to heavy RF suppression filtering when used with ungrounded UK plug adapters. - [02:30](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=150s) The IKEA Koppla delivers a stable 3.4A overall output without voltage droop and maintains a safe leakage current of 64 µA as a Class II double-insulated unit. - [04:15](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=255s) The primary stage incorporates robust protection, including an NTC inrush current limiter, common-mode choke, and a Pi-filter smoothing network. - [08:08](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=488s) Each USB port integrates an autonomous auto-detect SOT-23 chip on the D+/D- lines to negotiate charging profiles up to 2.1A per port. - [08:08](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=488s) Thermal management separates heat-sensitive electrolytic capacitors from the diode heatsink, utilizing natural convection inside the enclosure. - [10:27](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=627s) PCB spark gaps rated for approximately 10 kV protect internal components against severe electrostatic discharge introduced through the USB ports. - [10:27](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=627s) The high-frequency transformer features asymmetric keyed pins to eliminate reverse-insertion assembly errors. - [11:45](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=705s) The primary switch-mode IC relies on a combined bootstrap and auxiliary feedback winding to sustain continuous power and monitor output voltage. - [12:48](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=768s) The ferrite core is physically shielded by a tinned copper wire bonded directly to the primary negative rail to mitigate electromagnetic interference. - [17:19](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=1039s) Electrostatic screening between the primary and secondary is achieved via an insulated, grounded trifilar copper winding rather than traditional copper foil. - [20:26](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=1226s) A split-primary sandwich winding topology minimizes leakage inductance while fully protecting the triple-insulated secondary wire. - [27:07](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=1627s) A physical plastic blade molded into the case protrudes through the routed PCB isolation slot to guarantee creepage barrier separation. - [27:07](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=1627s) Clive strongly endorses the IKEA Koppla, concluding that its bespoke design and redundant safety features make it an exceptionally well-engineered budget charger.

## Detailed walkthrough ### [00:00](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=0s) USB Power Supply Safety and Dangerous Fakes

Clive begins by explaining his general philosophy on buying USB chargers. For a long time, he has advised viewers to stick to major, reputable brands. He frequently recommends genuine Apple chargers—clarifying that this is not out of brand loyalty, but because Apple is a massive corporation with a strong interest in protecting its reputation, leading them to design well-engineered, high-standard power supplies. He points out how critical 5V USB supplies have become in everyday life, powering everything from smartphones to desk lamps. However, this ubiquity brings severe safety hazards when consumers end up with counterfeit or poorly designed hardware.

Reflecting on past teardowns—such as a hazardous unit that had 240 volts live on exposed surfaces—Clive highlights how dangerous cheap chargers can be. He presents an imitation Apple charger that appears convincing on the surface, but teardowns reveal a terrifying design flaw: just 2 millimeters of physical isolation separating the high-voltage mains from the low-voltage DC rails. He shows a counterfeit charger branded as "Samsung," noting that genuine Samsung units would never be built like this. The fake simply routes low-voltage and mains tracks right next to each other at standard spacing across the board, completely lacking safety isolation.

He also showcases a budget charger purchased from Flying Tiger Copenhagen ("Tiger"), a retail chain with global stores known for novelty goods. Having previously torn down a purple variant, Clive considers Tiger units surprisingly decent—definitely a cut above no-name knockoffs—though, at around £5 including a cable, they cannot be expected to match the high engineering standards of premium brands.

> “So, it makes sense to get yourself a beefy, chunky, good quality supply that's safe.” — Clive

- **Counterfeit Apple Charger**: Features only 2 mm of clearance between mains and the low-voltage side, making it an extreme hazard. - **Counterfeit Samsung Charger**: Lacks galvanic isolation; high-voltage AC and low-voltage DC copper tracks run side-by-side without dedicated clearance. - **Tiger (Flying Tiger) Charger**: Sells for roughly £5 with a cable; far superior to generic fakes, but still built to budget constraints.

---

[02:30](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=150s) Comparing Apple and IKEA: Grounding and Leakage Current

Clive turns his attention to the genuine Apple charger and its design eccentricities. The Apple unit is modular, built with swappable plug adapters for international travel. It features a round metal stud on the back meant for sliding on country-specific mains pins. Interestingly, this metal pin connects internally toward the chassis and the negative rail to establish an earth reference. However, the UK three-pin plug adapter supplied with it does not include an internal mating contact for that stud, leaving the unit effectively unearthed in practice. Because of Apple's extensive, aggressive RF suppression filtering, Clive measured a leakage current of around 100 microamps (µA) on the Apple unit, meaning it is noticeably prone to giving users a mild electric tingle when brushed against.

In comparison, Clive measured the IKEA Koppla charger's leakage current at 64 µA, which is typical and well within expected norms for a double-insulated power supply. He observes that IKEA's packaging and manual include roughly 35 languages to accommodate international distribution. Because many global markets do not have earthed wall outlets, IKEA designs the Koppla as a Class II, double-insulated supply rather than relying on an earth pin. Clive notes that while a user might occasionally perceive a faint tingle on the sensitive skin of their hands due to the capacitive leakage inherent to switch-mode power supplies, the unit is stable. The IKEA Koppla is rated for an overall output of 3.4 amps; Clive tested it up to a 2 amp load and confirmed that it maintained its output voltage without drooping.

> “And you are likely if in some scenarios you'll get a very faint tingle, particularly in the back of your hand if you brush against something while you're holding an object that's plugged into this.” — Clive

- **Apple Charger Leakage**: Measured at ~100 µA due to substantial RF suppression capacitor filtering. - **IKEA Koppla Leakage**: Measured at 64 µA, comfortably compliant with double-insulated standards. - **IKEA Koppla Total Rating**: 3.4 A across its USB ports; verified stable under Clive's 2 A benchmark test.

---

[04:15](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=255s) Cracking the Koppla Case and Primary Filtering Stage

Opening the IKEA Koppla proves to be a physical challenge. Knowing that IKEA products are tightly snapped together or ultrasonically welded, Clive pauses the recording to avoid forcing the audience to endure the wrestling match. He returns after cracking the enclosure using a hammer and a pair of pipe grips. Inside, the shell incorporates plastic alignment pins, though the strength of the seal suggests it was glued or welded rather than just clipped. To inspect the circuit board freely, he snips the primary input leads.

```mermaid flowchart LR accTitle: Koppla Primary Input Stage Flowchart accDescr: Flow diagram showing mains AC input passing through NTC thermistor, common mode choke, bridge rectifier, and Pi-filter.

subgraph Primary_Protection["Mains Input & Inrush"] AC["Mains Input"] --> NTC["NTC Thermistor (NTC1)"] end

subgraph Filtration["EMI & Rectification"] NTC --> CMC["Common Mode Choke"] CMC --> BR["Surface-Mount Bridge Rectifier"] end

subgraph Smoothing["DC Smoothing"] BR --> C1["Smoothing Capacitor 1"] C1 --> L1["Inductor Choke"] L1 --> C2["Smoothing Capacitor 2"] C2 --> PWM["Switch-Mode Controller & FET"] end ```

Examining the printed circuit board, Clive immediately praises the professional layout, highlighting clean track isolation and integrated spark gaps on the high-voltage side. The mains input passes directly through an NTC (negative temperature coefficient) thermistor labeled `NTC1`. The NTC acts as an inrush current limiter; when cold, its higher initial resistance suppresses current spikes that occur when charging empty primary filter capacitors, preventing household breakers or power strips from tripping on plug-in. Following the NTC, the line passes through a common-mode choke—where live and neutral are wound in opposing directions on a single core so that 50 Hz AC passes unhindered while high-frequency noise and switching transients induce opposing magnetic fields that cancel out. The AC is rectified by a dedicated surface-mount bridge rectifier with well-spaced corner solder pads, followed by a pi-filter arrangement consisting of a first smoothing capacitor, an inductor choke, and a second smoothing capacitor to thoroughly eliminate ripple before reaching the primary switching transistor and controller IC.

> “Oh, look at the severation. Uh oh, look at the spark gaps and everything. This is this is like pro.” — Clive

- **Enclosure Fastening**: Sealed securely using heavy internal plastic alignment pins and adhesive/welding, requiring pipe grips and a hammer to crack open. - **Inrush Protection**: Negative Temperature Coefficient thermistor (`NTC1`) prevents primary capacitor surge currents from tripping breakers. - **EMI Suppression**: Common-mode inductor choke blocks high-frequency differential/transient noise from leaking back into the mains grid. - **Mains Rectification & Smoothing**: Surface-mount bridge rectifier arranged with corner pads for maximum separation, followed by a dual-capacitor and choke Pi-filter network.

---

[08:08](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=488s) Primary Switcher, Secondary Rectifier, and Port Controllers

Looking closely at the active electronics, Clive identifies the primary switch-mode power supply controller, noting obscure markings that read roughly `1699-02 R5 1 gh`. It drives an external switching transistor, which feeds the high-frequency transformer. Clive remarks that while destructive teardowns of functional, high-quality hardware feel almost criminal, destructive testing is necessary because external appearances can be deceiving—as seen on previous teardowns where neat transformers concealed dangerous internal wiring.

On the secondary side, rectified 5V DC is produced via a heavy diode mounted to its own dedicated heatsink. Clive approves of the component layout, noting that the sensitive electrolytic smoothing capacitors on the output have been intentionally positioned away from the diode’s heatsink to protect them from heat degradation. Looking closely at each USB output port, he spots tiny SOT-23-style surface-mount ICs bearing miniature laser-etched markings reading `1988 D` and `GIC CER`. He explains that each port has one of these dedicated auto-detect chips connected across the 5V and 0V power rails with outputs routed to the USB $D+$ and $D-$ data pins. These chips actively negotiate charging profiles with connected devices (such as phones and tablets), signaling to the connected gadget that the port can deliver up to its individual rating of 2.1 amps.

> “It feels a criminal thing taking this power supply, you know, to bits and ruining it when it's a perfectly good working power supply. But if I do it, uh, you guys don't have to.” — Clive

- **Primary PWM Controller Markings**: Marked with `1699-02 R5 1 gh`, driving a separate power switching transistor. - **Output Diode**: Mounted directly to a metal heatsink; Clive highlights that output filter capacitors are spaced away from this heat source to prevent premature drying out. - **Per-Port USB Auto-Detect ICs**: Tiny SOT-23 packaged chips marked `1988 D` bridge the power rails to the data pins ($D+/D-$) to communicate with connected devices and authorize up to 2.1 A charging rates.

[10:27](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=627s) Isolation Gaps, Spark Gaps, and Transformer Removal

Big Clive inspects the isolation boundary on the circuit board, noting an exceptionally wide physical gap that features an actual routed cutout across the substrate alongside the Class-Y safety capacitor. He also spots two integrated PCB spark gaps across the isolation barrier. He deduces these serve as a protective fail-safe against electrostatic discharge (ESD) introduced via the output ports:

> “You know, if you go to plug something and you've got a high static charge, it means that if the voltage exceeds the rating of all these components as a last resort, it can jump physically across as a spark.”

He estimates that crossing this gap would require roughly 10 kV. Turning his attention to the Class-Y suppression capacitor, he checks the marking to verify whether it is 10 nF before confirming it is actually a 1 nF capacitor.

To inspect the transformer's internal build quality, Clive desolders it from the board. Because the Koppla uses a single-sided printed circuit board, the transformer comes out cleanly without fighting through-plated holes. Examining the removed component, Clive appreciates the deliberate pin design: the pins on one side are aligned sideways, while the opposite side is aligned longways. This asymmetry guarantees proper orientation during assembly and prevents accidental reverse insertion.

- **Isolation Routing:** PCB slot cut out beneath the Class-Y capacitor to extend creepage distance. - **Spark Gap Threshold:** Estimated ~10 kV breakdown voltage to protect primary components from ESD. - **Class-Y Capacitor Value:** 1 nF. - **Transformer Pinout:** Asymmetric pin alignment (transverse vs. longitudinal) for foolproof keyed mounting.

---

[11:45](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=705s) Switch-Mode Architecture and Bootstrap Circuits

Clive examines the pinout and circuit topology of the transformer. It follows the standard architecture for modern switch-mode power supplies, containing a high-voltage primary winding, an auxiliary winding on the mains side, and an isolated low-voltage secondary output feeding the 5V rail. Clive explains that the auxiliary winding is not solely a bootstrap winding; it functions as combined bootstrap and voltage feedback.

When the power supply is initially plugged into the mains, there is a brief startup delay while a tiny capacitor charges through a high-value dropper resistor. Once that capacitor reaches operating threshold, the controller chip switches on and starts pulsing the transformer. At that point, the auxiliary winding generates power through a rectifier diode to run the IC continuously—effectively sustaining its own power supply while simultaneously monitoring output voltage behavior via magnetic coupling. Clive remarks on how component-dense the board is compared to typical budget switch-mode adapters:

> “In fact this is for a a modern switch power supply. This is a lot of support components. It's really quite a complex uh unit.”

The third winding provides the galvanic isolation separating the lethal 300 V DC bus from the 5V USB output that users come into direct contact with.

```mermaid flowchart TD accTitle: Koppla Primary Bootstrap and Auxiliary Supply Loop accDescr: Diagram illustrating how the primary IC starts via a high-value resistor and self-powers via the auxiliary winding. subgraph Startup ["Mains Startup Phase"] Mains["~300V DC Rail"] -->|"High-value resistor"| Cap["Small Startup Capacitor"] Cap -->|"Threshold reached"| IC["Control IC Starts Switching"] end subgraph Running ["Running Phase"] IC -->|"Drives switching pulse"| Pri["Transformer Primary"] Pri -->|"Inductive coupling"| Aux["Auxiliary / Feedback Winding"] Aux -->|"Diode rectified"| IC Pri -->|"Galvanic isolation"| Sec["5V Secondary (User Touch Safe)"] end ```

---

[12:48](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=768s) Dissecting the Transformer: Shielding and the Outer Primary

Clive begins dismantling the transformer by slicing through the outer insulating tape. He observes that all flying leads on the mains side have protective sleeving applied where they exit the coil, and the transformer casing features an ink-stamped part number and date code. However, tearing into the core proves difficult: the ferrite core is housed inside a dedicated plastic shell and heavily potted in hard lacquer.

After applying force with a screwdriver to crack open the glued assembly, Clive uncovers a peculiar construction detail: a bare copper wire, tinned at its contact point and tied directly to the primary negative rail, is wrapped tightly around the outside of the bare ferrite core and glued in place with lacquer. He identifies this as an uncommon measure to ground and screen the ferrite core against electromagnetic interference.

Peeling back the outer layer of polyester tape, Clive starts unwinding the first copper layer. Expecting an auxiliary feedback winding, he traces the connection and realizes it is actually an interleaved outer section of the primary winding tied directly to the positive rail:

> “And the secondary does have that thick insulation which is intact which is good. That was the weakness. That was the failing point in the squeeze unit. the secondary in insulation had been violated.”

This outer primary layer runs cleanly across the bobbin without encroaching on the secondary side, terminating at a center-tap loop that passes beneath the tape to join the deeper primary winding.

---

[17:19](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=1039s) The Mysterious Multi-Strand Screening Layer

Underneath the outermost primary section, Clive uncovers what initially appears to be an anomalous loose connection: a small cluster of wires folded into the bobbin that appears to terminate nowhere. For a moment, he wonders if he snapped a lead or stumbled across an open, single-ended capacitive feedback pickup.

Unwinding the layer reveals a ribbon of three parallel copper strands wrapped around the circumference of the coil. All three strands join together at one end to a single pin on the primary side, while their opposing ends are clipped flush and insulated under the tape barrier. Clive recognizes this as a multi-wire electrostatic Faraday shield, designed to block high-frequency common-mode noise between the primary and secondary windings:

> “Sometimes I think there's a you know the switch mode power supplies is a bit of a black art at times that the high frequencies that operate at just normal rules do not apply.”

Rather than using a solid strip of copper tape with an insulating gap—as was done in the dangerous generic "Squeeze" power supply he previously reviewed—this transformer achieves electrostatic shielding using a parallel trifilar wire winding grounded at a single node.

---

[20:26](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=1226s) The Secondary and Inner Primary Layers

Continuing inward, Clive reaches the secondary winding. Where the secondary leads cross adjacent primary and feedback connections, the crossing wires are protected with auxiliary sleeves. The secondary itself is wound from thick, double-insulated wire (reinforced three-layer or triple-insulated winding wire). Unlike cheap counterfeit chargers where tight winding machines scrape away fragile enamel insulation, this heavy insulation remains fully intact across the entire run.

Beneath another tight barrier of polyester tape lies the auxiliary feedback winding. Clive unravels this layer and finds it is wound with a parallel cluster of three wire cores that connect to the middle pin feeding the IC via a diode, with the return line tied to the primary ground.

Finally, Clive reaches the bottom of the bobbin and unwinds the inner primary winding. This section consists of a dense count of enameled wire turns running directly onto the center plastic bobbin spindle, completing the connection to the primary switching transistor loop. Clive confirms that the transformer utilizes a classic split-primary sandwich structure (interleaving the secondary and auxiliary between an inner and outer primary layer) to minimize leakage inductance while maintaining robust dielectric isolation:

> “So, so far it does look like it's a been a sensibly designed transformer and care has been made, you know, taken in making it. So, um, coupled with the other features here, the isolation features, this does look, as you'd expect from IKEA, it does look quite a well-designed supply.”

[25:41](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=1541s) Internal Layout, Thermal Design, and Wiring Quality

Examining the exposed board and transformer, Big Clive remarks on how surprisingly complex the unit is, noting the sheer volume of supporting components surrounding the unusual transformer. Despite the complexity, everything in the construction checks out as well-designed. The circuit features robust input filtering, inrush current limiting, and modest, supported heatsinks on both the primary switching side and secondary rectifier diode side rather than components flapping loose on their leads. Between the high-voltage mains and low-voltage secondary circuitry, the board features generous creepage distances, spark gaps, and an isolation slot milled right through the PCB where the transformer windings cross over. Furthermore, the electrolytic capacitors are deliberately kept away from the heatsinks to avoid heat-induced degradation.

Clive observes that the physical orientation of the charger when plugged into a wall outlet works to its thermal advantage. As installed, heat rising off the heatsinks naturally drifts toward the top of the casing, carrying thermal energy away from the sensitive capacitors below. Small ventilation openings visible in the USB port frames allow for a modest amount of air circulation, at least until all three ports are plugged in under maximum load. He also praises the primary mains connections coming off the rear prongs, which use heavy, high-rated wire with two layers of insulation rather than the flimsy, hair-thin wires commonly encountered in cheap generic imports.

- Built with dedicated inrush current limiting and comprehensive mains filtering. - Rigidly mounted, supported heatsinks for both the primary transistor and the secondary rectifier diode. - Physical isolation slot milled through the PCB beneath the transformer to separate mains potential from low-voltage rails. - Heavy-gauge mains lead-in wires featuring dual-layer insulation.

---

[27:07](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=1627s) Enclosure Construction, Isolation Blade, and Final Verdict

Turning his attention back to the plastic casing, Clive removes two screws near the mains pin assembly to see if the plug section detaches as part of a modular universal casing for different regional adapters. Although the outer cover is clipped tightly in place and does not easily separate, he notes that it appears to be an assembly tailored specifically for the UK variant. Surveying the disassembled parts spread across his bench, he jokingly acknowledges that the disassembled charger is a “wondrous mess that's never ever going to go back together again,” but remains impressed with its build quality.

```mermaid flowchart TD accTitle: Koppla Physical Safety and Retention Layout accDescr: Diagram illustrating how the enclosure case interacts with the PCB via plastic blades and anchor pillars.

subgraph Enclosure["Molded Outer Casing"] Blade["Molded Plastic Isolation Blade"] Pillars["3x Internal Anchoring Pillars"] end

subgraph PCB["Power Supply Circuit Board"] Slot["Milled Isolation Slot"] MountPoints["Firm Retention Points"] end

Blade -->|"Protrudes through"| Slot Pillars -->|"Firmly clamp into place"| MountPoints ```

He highlights two final engineering details molded directly into the housing. First, the isolation gap cut through the circuit board aligns directly with an internal molded plastic blade on the case shell; when assembled, this plastic fin slides completely through the slot to create a physical barrier between the primary and secondary domains. Second, the case incorporates three rigid anchoring posts—one at the top and two near the base—that clamp down on the board to keep it locked firmly in position. Impressed by the safety engineering, Clive gives the unit an emphatic endorsement: “Would I buy another IKEA power supply like this? I think I would. It seems to be quite well engineered.”

- Internal plastic blade protrudes entirely through the milled circuit board slot to enforce physical barrier isolation between mains and low-voltage rails. - Three molded internal retention posts clamp the PCB securely in place against physical shock. - Overall construction indicates a product thoroughly designed from scratch with deliberate attention to electrical safety standards.

## Notable quotes > [00:00](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=0s) So, it makes sense to get yourself a beefy, chunky, good quality supply that's safe. — Clive

> [27:07](https://www.youtube.com/watch?v=uRe9w5PKmsE&t=1627s) Would I buy another IKEA power supply like this? I think I would. It seems to be quite well engineered. — Clive

## Mentioned IKEA, IKEA Koppla, Apple, Samsung, Flying Tiger Copenhagen, bigclivedotcom

## Video description I've always recommended using prominent brand USB chargers for safety. So I thought I'd take an IKEA one to bits and assess it for safety with regards to isolation and transformer construction.

If you enjoy the videos on this channel you can help support it with a dollar for coffee, cookies and things to take apart at https://www.patreon.com/bigclive

[Source](https://www.youtube.com/watch?v=uRe9w5PKmsE)

中文简报

宜家Koppla USB电源拆解：具备出色的市电隔离设计拆解显示，这款平价适配器采用了多层变压器屏蔽、浪涌保护以及一体成型的塑料隔离隔板，消除了低成本充电器中常见的触电隐患。 Big Clive拆解了一款宜家Koppla三口USB电源，将其做工和安全性与危险的假冒充电器进行了对比评估。在测得符合标准的64微安漏电流并撬开焊接的外壳后，他检查了PCB上完备的输入保护、浪涌热敏电阻、共模滤波以及自动识别充电芯片。随后，他彻底拆解了高频变压器，发现了设计精良的交错三明治结构、静电法拉第屏蔽层以及厚实的次级导线绝缘。在看到出色的散热规划、PCB开槽隔离以及内部塑料阻隔板后，Clive总结认为该充电器的工程设计极为优秀，十分安全且值得推荐。对宜家Koppla 3.4A USB电源的破坏性拆解证实其符合严格的安全标准，这与市电和低压轨之间隔离距离甚至仅有2毫米的危险仿冒品形成了鲜明对比。 (0:00) 双重绝缘的宜家Koppla测得的漏电流为64微安，远低于未接地正品苹果充电器上观察到的约100微安。 (2:30) 内部剖析展现了复杂的安全工程设计，包括交错的分裂初级变压器、接地的三线并绕静电屏蔽层以及双重绝缘的次级导线。 (12:48) 外壳与PCB具备强大的物理隔离设计，结合了电路板开槽、一体成型的塑料阻隔板以及耐压约10 kV的放电间隙。 (10:27)

Source quotes

[0:00] Clive: So, it makes sense to get yourself a beefy, chunky, good quality supply that's safe. [27:07] Clive: Would I buy another IKEA power supply like this? I think I would. It seems to be quite well engineered.

Original transcript

[0:00] In the past, I've tended to recommend [0:02] that if you want a decent USB power [0:04] supply, go for a prominent brand. And [0:06] I've I've recommended the Apple one, not [0:08] because I'm an Apple fanboy, but because [0:10] Apple's a huge American brand, and they [0:12] want to protect that brand, and they [0:14] take things seriously, so their power [0:16] supplies are wellmade. Likewise, I'm [0:19] hoping that this IKEA one is good, too. [0:22] And we're going to find out shortly [0:23] because I'm about to open this up. The [0:26] SW one. Yes. After finding this one was [0:29] live at 240 volts, that was a, you know, [0:32] that really drove home the message that [0:34] you have to, you know, these things are [0:37] so important. We need 5V power supplies. [0:40] We need USB power supplies cuz from, you [0:43] know, things like the phones to lights, [0:45] you know, we plug lots of stuff into 5 [0:47] volts. It's become an industry standard. [0:49] So, it makes sense to get yourself a [0:51] beefy, chunky, good quality supply [0:54] that's safe. And when you buy what look [0:56] like, you know, what look like Apple and [0:59] you get them fairly cheap or even pay [1:01] full price but get them from a [1:02] nonauthorized source, you could be [1:04] getting something like this that is [1:06] based on the one of the Apple chargers. [1:09] But this one in particular is notable [1:12] for the fact it's got 2 mm separation [1:14] between the mains and the low voltage [1:17] side. So it's therefore a complete death [1:19] trap. Likewise, this one that is printed [1:21] Samsung, but is really not Samsung. I [1:25] mean, I I don't think Samsung would put [1:26] something like this out because it again [1:29] does not have any proper isolation. It's [1:31] just they've just run the tracks at the [1:33] same distance as everything else. So, [1:34] it's mains here. Low voltage there. So, [1:36] again, not safe. And then you get the [1:39] brands like the the Tiger. Now, I've [1:42] already opened one of these. It was a [1:43] little purple version of this. I quite [1:45] like these cuz all the the colors, but [1:47] Tiger is a sort of like similar to IKEA [1:50] in a way. It's sort of novelty stuff. [1:52] And they've got shops all around the [1:54] world. This one seemed actually pretty [1:56] good. Um, it was very much a cut above [2:00] the cheap generic ones, but I don't [2:02] think it was quite up to the standard. [2:03] Well, hope hopefully I've not opened one [2:04] of these yet. I'll soon find out, but I [2:07] wouldn't expect it to be up to the [2:08] standard of things like the Apple one or [2:10] the IKEA one because this is a lot [2:12] cheaper. It's something like5 with the [2:14] lead and stuff like that. So, uh, let's [2:16] take a look at the Let's get all the [2:19] lesser ones out the way. And I'll just [2:22] move this one slowly out the way because [2:23] it's not quite so lesser. It's actually [2:25] I use these. I think they're okay. Uh [2:27] and we'll take a look at the Apple. Now, [2:30] here's a weird thing. The Apple charger [2:33] is modular. It's designed to be used in [2:35] various countries. So, it comes with [2:37] various adapters. And it's got this [2:39] metal pin in the back. And it's not just [2:40] for anchoring things. This metal pin is [2:43] connected not directly but it is [2:45] connected uh to the negative rail of the [2:49] you know it's connected to the shell so [2:51] there is a reference to earth but [2:52] strangely although this is this has got [2:54] a metal earth pin it's not got the [2:56] matching connection in here I don't know [2:57] why they did that so it's not earth and [3:00] this one has what you might call good [3:03] suppression RF suppression circuitry as [3:05] you'd expect from a company like Apple [3:08] but that means that of all the units I [3:10] tested this one was the most likely to [3:12] give you a tingle uh because it it had [3:14] quite a high leakage current of about [3:15] 100 micro amps. This one I've tested the [3:18] leakage current. It has a leakage [3:21] current the IKEA unit of 64 micro amps [3:24] which is typical typically what you'd [3:26] expect. They're classing it as a double [3:27] insulated unit. And I'm guessing that as [3:30] with IKEA has I mean the instructions [3:33] with IKEA come in about 35 languages. So [3:35] they use these in every country and not [3:37] every country has earthing. So I think [3:39] they just base it on unearthed supplies, [3:42] you know, and in this case they could [3:44] have added that extra metal pin, but [3:47] they just class as a double insulated [3:48] appliance. And you are likely if in some [3:51] scenarios you'll get a very faint [3:53] tingle, particularly in the back of your [3:54] hand if you brush against something [3:56] while you're holding an object that's [3:57] plugged into this. It's just the nature [3:59] of these power supplies and switch mode [4:01] power supplies. But um the IKEA unit is [4:05] rated 3.4 amps. Uh, I've given it a good [4:08] test. I've tested up to two amps and it [4:10] held the voltage absolutely fine. So, [4:12] um, let's just open it. And this is [4:15] where I'm going to have a go opening [4:16] this. And I know from opening previous [4:18] IKEA com products that they're sometimes [4:21] quite hard to open. They're really snap [4:23] together very [4:25] well. And it might even be glued. I [4:27] don't really know. Uh, so if this [4:30] doesn't come [4:31] apart [4:33] quickly, then I'll pause just so you [4:35] don't have to experience the [4:38] excruciating uh ex sight of me bursting [4:41] the case open. Yeah, this thing is I can [4:44] already tell this is going to be chewed [4:46] up. So, um, yes, I'll pause the video [4:47] and I'll be back shortly. Okay, that [4:50] wasn't too bad. All it took was a few [4:52] taps the hammer and then the pipe grips [4:55] uh into it to actually burst that case [4:58] open. It appears to be it was quite [5:00] nice. It's got these plastic pins that [5:02] push into here. I'm not sure if that's [5:04] just for alignment. Uh I got the feeling [5:07] it was glued, but maybe it's [5:09] not. It's not overly 100%. I'm not [5:13] seeing the shredded remnants you'd [5:14] normally expect from from glue. All I'm [5:18] seeing is shredded remnants where where [5:19] I've used unreasonable force. So, um [5:22] that uh yeah, it's it yeah, it must have [5:25] been glued because it's not really [5:27] coming up going back together that [5:29] easily unless these pins are tight [5:30] friction fit. But anyway, I digress. [5:32] Let's uh let's get into it. And uh uh [5:36] you know what? I'm just going to cut [5:38] that off. Let's cut it off so we can [5:40] take a good look at this. I'm going to [5:41] be destroying this completely because uh [5:44] as we've discovered from the Squeeze [5:46] unit, just because it looks like a good [5:49] transformer doesn't mean it is a good [5:51] transformer. So, let's see what this is [5:53] using. [5:55] little switchboard power supply chip is [6:00] oh it's marked [6:03] 1699-02 [6:05] R5 [6:07] 1 [6:11] gh I'm not 100% sure that is okay let's [6:16] just say generic switchboard power [6:18] supply so we got the mains come in here [6:20] we've got what looks like a little [6:21] inrush current uh uh yep NTC1. It's a [6:25] negative temperature coefficient [6:26] thermister. Now, these are little [6:28] resistors, basically heat sensitive [6:30] resistors that start off with a fairly [6:32] high resistance and then as they heat [6:34] up, it goes lower. And that means that [6:36] when you plug it in, initially it stops [6:39] that huge surge of current in because [6:41] what's happening initially is that the [6:43] current's going through this bridge [6:44] rectifier and charging these capacitors, [6:46] which I haven't discharged, but I now [6:48] have now because I've stuck my finger [6:49] across them. Oh, look at the severation. [6:52] Uh oh, look at the spark gaps and [6:53] everything. This is this is like pro. Uh [6:56] so the mains comes in. It gets that [6:59] nasty surge in just limited by this NDC [7:02] thermister which means if you got lots [7:04] and lots of things plugged in and they [7:06] you know suppose you had like a [7:07] multi-way adapter with lots of these [7:08] plugged in it means it's not going to be [7:10] such a high surge that it's going to [7:11] cause things to trip out or crash. Uh [7:15] then it's got a common mode uh inductor [7:17] which is a inductor with a the live and [7:20] neutral wound around it in sort of [7:21] opposite directions so that low [7:24] frequencies like mains 50 Hz will just [7:26] pass through it without any effect. But [7:28] high frequency noise or transients will [7:30] effectively induce a magnetic field that [7:32] cancels each other out because they're [7:33] going in opposite directions. That then [7:36] goes through a bridge rectifier which is [7:37] a surface mount one with good separation [7:40] all the way through. Uh it's tacked. Uh [7:44] the solder connectors are on each corner [7:45] for maximum separation. A smoothing [7:48] capacitor. [7:50] A [7:51] choke. Another smoothing [7:55] capacitor. So [7:57] um this looks like, you know, they're [8:00] making an effort for good [8:03] filtration. Then we've got the little [8:05] switch mode chip and its transistor. [8:07] We've got the transformer here, which [8:08] I'm going to have to take to bits, [8:10] obviously, because there's no other way [8:11] we can actually determine, you know, [8:13] although it looks good, it looks quite [8:15] nicely made. Um, we don't know what's [8:18] inside. So, I'm going to remove that. [8:19] I'm going to desolder it and then we'll [8:21] investigate what's in it. It's It feels [8:23] a criminal thing taking this power [8:26] supply, you know, to bits and ruining it [8:28] when it's a perfectly good working power [8:29] supply. But if I do it, uh, you guys [8:31] don't have to. So, that's the whole [8:33] point of this channel. Well, one of the [8:35] points of this channel. So, we've got [8:38] the output goes through this [8:41] uh heat sink diode. Uh and then it's [8:45] got these little uh I see this quite [8:48] commonly in these ports. It's got these [8:50] tiny little [8:52] chips that are being used to and the [8:55] text is absolutely minute on them. It [8:58] really is. I'm gonna have to actually [8:59] take a look through a microscope at that [9:01] text. It's absolutely they tried to put [9:04] a whole chips number onto a tiny little [9:07] sock 23ish type [9:09] package which is so small that I'm not [9:11] even finding it here. Where is [9:15] it? Oh, I'm not finding [9:20] it. It [9:23] says [9:25] 1988 D. If that makes any sense. [9:31] I guess they're all the same. I think [9:32] it's just one per [9:37] port. Yes. [9:41] 198. And I'm guessing and underneath it [9:44] says GIC [9:46] CER. I'm guessing those are for [9:49] negotiating how much power the USB [9:51] device can have. This thing says about [9:53] 2.1 amp max per outlet. [9:56] And these little chips tend to basically [9:59] be connected across the 5 volt and zero [10:01] volt. And then the two outputs the chip [10:03] are across the data pins. So this is [10:07] actually just providing some sort of [10:09] communication to the device that's [10:11] charging to say you know you can take [10:13] the maximum you can say take 2.1 amps if [10:16] you want. Um the capacitors and output [10:19] have been kept away from the diode heat [10:22] sink which is nice. Not so much there, [10:24] but it's still enough [10:27] spacing. And it's got the class Y [10:29] pressure capacitor. It's got absolutely [10:30] mega gap there with a proper with an [10:33] actual routed section out [10:37] there. And uh the little spark gaps, two [10:40] spark [10:41] gaps, which I'm guessing is for when [10:43] you've got an electrostatic discharge on [10:45] the output. You know, if you go to plug [10:47] something and you've got a high static [10:49] charge, it means that if the voltage [10:50] exceeds the rating of all these [10:52] components as a last resort, it can jump [10:54] physically across as a spark. But that [10:56] would be about 10 KV. That'd be quite a [10:58] high [10:59] voltage. Um, the class Y [11:05] capacitor is that 10 [11:10] nano? No, it must be one nano actually. [11:16] Yeah, one nano fart. [11:19] Okay. Right. So, uh, now I have to take [11:22] this transformer off. And that means [11:23] cutting it, uh, trying to get it off the [11:25] board. It's, at least it's a [11:26] single-sided board. Um, I shall be back [11:29] in a [11:30] moment. That was actually fairly easy to [11:32] get out. Helped greatly by the fact it's [11:34] a single-sided board. I like the way [11:36] that the pins are sideways on this side, [11:38] but long ways in that side. Um, just to [11:41] make sure that there's, you know, [11:42] there's no confusion about the way the [11:43] transformer goes around. [11:45] It's the usual configuration. It's got [11:47] the primary winding plus a second [11:49] winding on the main side that provides [11:51] power to the chip. But in this case, [11:52] it's not purely what's called a [11:54] bootstrap winding. You get bootstrap and [11:56] feedback or sometimes they're combined. [11:59] Bootstrap is when it provides power to [12:01] the chip itself. Once the chip has [12:04] started, when you plug it in, there's [12:05] usually a slight delay as the capacitor, [12:08] in this case, it's this tiny little [12:09] thing here, charges via high value [12:11] resistor. And once it's got enough uh [12:14] charge in that then the chip itself will [12:16] burst into action. And as soon as it [12:18] does and starts driving the transformer [12:20] then effectively provides its own power [12:22] supply from that auxiliary winding. But [12:24] that's also used uh sometimes for [12:26] feedback. It will monitor the voltage in [12:28] that and it does seem to be doing that [12:29] here. In fact this is for a a modern [12:32] switch power supply. This is a lot of [12:34] support components. It's really quite a [12:36] complex uh unit. And the other winding, [12:39] the third winding is of course the [12:40] supposedly isolated uh secondary which [12:43] is going out to the uh the 5V circuitry [12:46] and the bit you're going to be touching. [12:48] So let's uh take the tape off this [12:50] transformer and take a look inside and [12:52] see what the quality is like. At the [12:54] moment I am seeing that the the main [12:56] side windings are all kind of sleeved [12:58] which is good. [13:05] It does look like an effort has been [13:06] made to actually make it relatively [13:09] safe. Now, where is the end of this? Oh, [13:12] and it's actually got a number on it [13:14] with a date as well. That's quite [13:19] good. Let's see if we can get this tape [13:24] off. So, we can get the bobbin apart and [13:26] take a look inside it. [13:39] Now, how is this thing stuck together? [13:41] It's looking quite odd, [13:49] actually. [13:50] The core is actually in a plastic [13:53] housing in this as well. It's not just [13:55] straight uh a straight metal core around [13:57] it. Uh how does this come apart? I may [14:00] have to pause again. This is not uh this [14:02] is not really immediately obvious how [14:04] this comes apart. I think it may involve [14:06] force. I'm just going to poke that with [14:08] a screwdriver first and see if I can [14:10] push that down. But I think the thing [14:12] may actually have all been sealed [14:14] up. It's not clear at all. I shall [14:18] pause. Well, this definitely isn't going [14:21] back together again. That was just well [14:22] glued together. And uh I have to say [14:25] there's an interesting thing. There's a [14:27] little extra wire um from here which is [14:29] connected to the the negative rail of [14:32] the power supply and it's just a bare [14:34] bit of copper wire. They've tinned it [14:36] and then it was wrapped around the [14:37] ferite core itself. Just actually glued [14:40] effectively by the the lacquer onto the [14:42] ferite as if it was maybe to screen the [14:45] ferite. I've not come across that. [14:47] That's quite odd. So let's uh go in [14:54] further. The first wind I'm expecting is [14:56] going to be the sort of bootstrap wind [14:58] because it's a or feedback because it's [15:01] not that critical in the sense that um [15:05] it's not the high current winding. So [15:07] it's sort of sort of it gets the last [15:11] connection so to speak. So it's coming [15:18] from that side and terminating. Let's [15:21] see. [15:33] Oh, this might actually be part of the [15:35] primary by the look of [15:37] it. [15:40] Okay, cuz it does look like this this [15:43] first [15:46] wire is coming from what looks like one [15:49] of the primary connections. [16:05] Yeah, that's connected to the plus 5 [16:07] volt [16:08] rail. So, that is one of the primary [16:11] connections. Okay, let's cut it. And [16:14] it's sleeved up just till it it just [16:19] it's a really short section of sleeve. [16:20] gotten it just to get it under the cover [16:22] here. Wonder why that uh wonder why that [16:25] is. Let's unwind this. Anyway, so this [16:28] looks like part of the [16:35] primary. And so far it's [16:37] not going too close to the secondary. [16:41] And the secondary does have that thick [16:43] insulation which is intact which is [16:45] good. That was the weakness. That was [16:47] the failing point in the squeeze unit. [16:49] the secondary in insulation had been [16:52] violated. So this winding comes round [16:56] and it goes to the midpoint tap. So that [16:59] was part of the primary [17:02] winding. I shall cut that off. Get it [17:05] out the way. And we shall go on to the [17:08] next layer. [17:19] This could be [17:21] the bootstrap feedback one or this next [17:25] one could be uh looks like the the [17:28] bootstrap [17:34] feedback odd. [17:45] There's just [17:50] a couple of tails that aren't connected [17:52] to anything. [17:56] Just cluster of wires. I I haven't [18:00] broken that, have [18:01] I? [18:03] Could that just be sensing [18:07] it [18:10] single-ended? That's odd. I didn't see [18:13] that connected to anything in there. It [18:14] just seemed to be just tucked up in and [18:16] under the [18:19] insulation. [18:22] Okay, so this is actually a cluster of [18:27] wires. Could they be relying on [18:29] capacitive coupling between them or [18:31] something? There's [18:32] this that's [18:36] weird. That's something that's new to [18:47] me. Almost like it's [18:49] a capacitively coupled feedback [18:54] winding, but also providing power to the [18:57] chip. If it's going to those two pins, [18:58] if it's going to these two pins, which [19:00] it may [19:03] do. I shall find out when I get to the [19:10] end. Now it's ducking underneath the [19:13] next layer of insulation. Oh no, it's [19:16] going. All those wires are connected to [19:18] one [19:21] pin. That's weird. [19:29] Oh, that's a screening [19:31] layer because there are two more [19:33] windings going in here. Okay. So, that's [19:36] a screening layer. That's the equivalent [19:38] of the piece of copper tape that was in [19:40] the uh in the squeeze [19:43] supply. So, it that whole winding was [19:47] actually just a a cluster of wires. It [19:48] looks like three wires just clustered [19:51] together. [19:58] Yeah, it just looks like a cluster of [19:59] three wires together with just one [20:01] connection at one end and just uh [20:03] wrapped round. So they are have some [20:04] sort of screening [20:06] effect, but yet part of the primary was [20:09] outside that. That's [20:11] weird. Sometimes I think there's a you [20:14] know the switch mode power supplies is a [20:16] bit of a black art at times that the [20:17] high frequencies that operate at just [20:20] normal rules do not apply. [20:26] It's clear that quite a lot of thought [20:28] and technology has gone into this [20:33] one. Then I took it to [20:43] bits. Okay, I'm trying to find the end [20:46] here. It's uh being elusive. When they [20:49] There's a point that when they put this [20:50] tape round um and then wrap it tightly, [20:54] it really just bonds onto [20:58] itself to the point you can't actually [21:00] see the end. So, off comes the next [21:03] layer. And what are we getting [21:05] now? Now, we're getting the [21:13] secondary. So where the secondary [21:16] crosses any of these other connections [21:19] like the the uh bootstrap feedback type [21:22] connection or the uh primary connection [21:26] they have also sleeved the primary as [21:30] well as the fact that this is a double [21:32] insulated. So this is a pair of [21:38] cords and they're relying primarily on [21:41] the double insulation on this and the [21:44] sleeving of those other connections for [21:45] the separation which is reasonable [21:48] enough. It is quite thick [21:52] insulation and it's intact. It's not [21:54] been chafted off as in that previous [21:57] horror the squeeze one. So, yep, a very [22:01] stout [22:03] um thick insulation uh [22:08] secondary. And now we're into [22:12] the inner layer, which is still going to [22:14] be it's going to be the the feedback. I [22:16] wonder if that's the very mid one or [22:18] not. I'm not really sure. And I'll find [22:20] out when we peel this off what's going [22:23] to be next. [22:31] Next is the feedback [22:34] winding by the look of [22:37] it. And again, it's a series [22:48] of So, this is the pin that's going to [22:51] the middle. So that's actually the one [22:54] that's going to power the chip via a [22:57] diode. And that is quite odd in that [23:01] it's it's another cluster [23:04] of is it three or four [23:10] wires? Three I think. That's very hard [23:13] to tell actually. Yeah, it's three [23:15] separate uh cores. [23:19] And I'm guessing this is probably, and [23:22] this is where I make a fool of myself [23:23] when it isn't connected to the negative, [23:25] which is [23:32] uh [23:38] there. [23:43] Okay. Right. Yep. That is the the [23:46] feedback [23:47] winding. And that just leaves the [23:51] uh final section of the primary [24:00] winding. So, so far it does look like [24:02] it's a been a sensibly designed [24:04] transformer and care has been made, you [24:06] know, taken in making it. So, [24:10] um, coupled with the other features [24:12] here, the isolation features, this does [24:15] look, as you'd expect from IKEA, it does [24:18] look quite a well-designed [24:20] supply. Surprised the amount of [24:22] circuitry on it. It's very heavy in the [24:23] circuitry [24:25] side. And this is now just coming over [24:28] to the primary side. [24:43] So if [24:44] I pop cut that [24:53] winding that is [24:56] the loop by the look of it that's where [24:59] the center point where it's actually [25:00] this was where this winding here was [25:02] connected to the outer winding. the very [25:04] outermost [25:08] winding and then fundamentally I'm just [25:11] expecting a plastic core in the middle [25:12] after [25:21] this good number of turns because it is [25:23] the primary after all. It's the main [25:25] side that's effectively switching about [25:27] 300 volts in this case from the [25:29] capacitor. Yes, it is just a plastic [25:31] cord that will be going to directly to [25:33] one of those [25:35] pins. [25:37] Um, which is that pin. Yep. So, it's an [25:41] unusual it's an unusual transformer. [25:43] It's a very complex, you know. It just [25:46] I'm surprised the amount of support uh [25:47] components in this, but um everything [25:50] seems to check out in the transformer. [25:52] It seems quite uh it seems quite well [25:54] designed. It's got good filtering. It's [25:56] got the inrush limiting. It's got the um [26:00] modest beefy little heat sink on the a [26:02] supported heat sink. It's not just [26:04] flapping loose as as is this side on the [26:06] the other side for the diode. Um it's [26:09] got the good separation gap, spark gaps. [26:12] It's got a slot through between the [26:14] mains and the low voltage where the [26:16] windings come off. And the transformer [26:18] itself seems to be quite sensibly made. [26:21] And it's got the support circuitry and [26:22] the capacitors are mounted away from the [26:23] heat sink. So, you know [26:25] what? This looks okay. Particularly [26:29] given the way it's designed to mount, [26:31] uh, is such that any heat from that heat [26:33] sink will be going up to the top of the [26:34] plug further away from those capacitors. [26:37] And there'll be a bit of air [26:38] circulation. I mean, I can see holes in [26:40] the USB casings. So, there's going to be [26:42] a we bit of air circulation in there as [26:44] well when they're not all stuffed with [26:46] plugs or which is point they'd be under [26:48] the most load. But, um, on the whole, [26:50] you know, and also these cables are [26:52] huge. It's not just the we flimsy things [26:54] you find in the Chinese uh plugs that [26:57] you know it's just we dinky thin wires. [26:59] These are actually quite heavy rated [27:01] cables [27:02] uh with two layers of insulation on them [27:04] coming from the back pins and onto this. [27:07] Oh, that also alludes to um how they do [27:09] the [27:11] multiple [27:13] adapters because if I undo this screw [27:15] and this screw, is this going to result [27:19] in a something separating and a [27:21] convincing? No, it's not actually. Oh, [27:24] that whole outer bit should come off but [27:26] isn't. Oh, it's probably clipped on as [27:28] well. Oh, that there it [27:30] is. That's strange. I wonder if they [27:34] Yeah. No, it must just be the assembly [27:36] just for for the UK version. But yes, uh [27:40] all in all, this uh wondrous mess that's [27:43] never ever going to go back together [27:44] again is well designed. Would I buy [27:46] another IKEA power supply like this? I [27:49] think I would. It seems to be quite well [27:52] engineered. Just a couple of other [27:54] things worthy of note. When you put the [27:56] circuit board in, this uh isolation gap, [27:58] the slot through the circuit board [28:00] actually has a plastic blade molded into [28:03] the case that when you put it in, that [28:05] comes right through that slot and [28:07] provides extreme separation. Also, when [28:10] you put this in, it's got uh three [28:12] anchoring points that actually push that [28:15] whole circuit board, one up here and two [28:17] down here that press that circuit board [28:19] firmly into place. So, it's uh also [28:21] quite a robust unit. It seems [28:23] welldesigned from scratch. You know, it [28:25] really has been. A lot of thought seems [28:27] to have gone into this. It seems to be a [28:29] good supply.