Top Ten Reasons Not To Buy A Fake MacBook Charger. Number Eight Will Shock You.

Yesterday, Apple showed the world how courageous they are by abandoning their entire PC market. It’s not time for a eulogy quite yet, but needless to say, Apple hardware was great, and the charger was even better. It had Magsafe, and didn’t start fires. What more could you ask for?

When it comes to fake MacBook chargers, you can ask for a lot more. [Ken Shirriff] has torn apart a number of these chargers, and his investigations allowed for an obvious pun in this post. The fake ones will make sparks thanks to the cost-saving design, and shouldn’t be used by anyone.

A genuine Apple MacBook charger is a phenomenal piece of engineering, but the fake one is not. In fact, it’s almost the simplest possible AC to DC converter. The mains power comes in, it’s chopped up into pulses, and these pulses are turned into a high-current, low-voltage output in a flyback transformer. This output is converted into DC with a few diodes, filtered, and wired into a MagSafe adapter.

The genuine MacBook charger is much more complicated. Like the cheap copy, it’s a switching power supply, but has a few features that make it much better. The genuine charger does power factor correction, uses quality caps, has real isolation on the PCB, and uses a microcontroller that’s almost as powerful (and a direct architectural descendant) as the CPU in the original Macintosh. It’s this microcontroller that kept you safe that one time you decided to lick a Magsafe connector not allowing the full 20 Volts to go through until the connector has connected. Until then, the Magsafe connector only outputs 0.6 Volts. The fake charger doesn’t do this, and when you poke the connector with a paper clip, sparks fly.

This isn’t [Ken]’s first teardown of genuine and not Apple products. He’s done iPad chargers, iPhone chargers, and other small, square, white switching power supplies. The takeaway from these teardowns is that cheap chargers are a false economy, and you probably should pony up the cash for the real version.

USB Soldering Iron is Surprisingly Capable

We know what you’re thinking. There’s no way an 8 watt USB-powered soldering iron could be worth the $5 it commands on eBay. That’s what [BigClive] thought too, so he bought one, put the iron through a test and teardown, and changed his mind. Can he convince you too?

Right up front, [BigClive] finds that the iron is probably not suitable for some jobs. Aside its obvious unsuitability for connections that take a lot of heat, there’s the problem of leakage current when used with a wall-wart USB power supply. The business end of the iron ends up getting enough AC leak through the capacitors of the power supply to potentially damage MOSFETs and the like. Then again, if you’re handy to an AC outlet, wouldn’t you just use a Hakko? Seems like the iron is best powered by a USB battery pack, and [BigClive] was able to solder some surprisingly beefy connections that way. The teardown and analysis reveal a circuit that looks like it came right out of a [Forrest M. Mims III] book. We won’t spoil the surprise for you – just watch the video below.

While not truly cordless like this USB-rechargeable iron, we’d say that for the price, this is a pretty capable iron for certain use cases. Has anyone else tried one of these? Chime in on the comments and let us know what you think.

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Tearing Down an IP Camera

So you bring home a shiny new gadget. You plug it into your network, turn it on, and it does… well, whatever it wants. Hopefully, it does what you expect and no more, but there is no guarantee: it could be sending your network traffic to the NSA, MI5 or just the highest bidder. [Jelmer] decided to find out what a new IP camera did, and how easy it was to find out by taking a good poke around inside.

In his write-up of this teardown, he describes how he used Wireshark to see who the camera was talking to over the Interwebs, and how he was able to get root access to the device itself (spoilers: the root password was 1234546). He did this by using the serial interface of the Ralink RT3050 that is the brains of the camera to get in, which provided a nice console when he asked politely. A bit of poking around found the password file, which was all too easily decrypted with John the ripper.

This is basic stuff, but if you’ve never opened up an embedded Linux device and gotten root on it, you absolutely should. And now you’ve got a nicely written lesson in how to do it. Go poke around inside the things you own!

555 Teardown and Analysis

If you are even remotely interested in electronics, chances are the number ‘555’ is immediately recognizable. It is, after all, one of the most popular IC’s ever built, with billions of units sold to date. Designed way back in 1970 by Hans Camenzind, it is still widely available and frequently used for various applications. [Ken Shirriff] does a teardown and analysis of a 555 and gives us a look at the internal structure of this oldie.

A metal can package allowed him to just chop off the top and get access to the die, which was way safer and easier than to etch out the black epoxy of a DIP package. He starts by giving us a quick run down on how the chip works, showing us the two comparators, the output flip-flop and the capacitor discharge circuitry that make up most of the chip. He then puts the die under a metallurgical microscope, and starts identifying the various sections of the chip. Combining pictures of individual elements with cross-sectional diagrams, he identifies the construction of the transistors and resistors, the use of a current mirror to replace bulky resistors, and the differential pair that makes up the comparators.

He wraps it up by providing an interactive map of the die and the schematic, where you can click on various parts and the corresponding component is highlighted along with an explanation of what it does. There’s some interesting trivia about how a redesigned, improved version – the ZSCT1555 – couldn’t survive the popularity and success of the 555. He wraps it up with a useful list of notes and references. While de-capping blog posts are interesting on their own, [Ken] does a great job by giving us a detailed look at the internals.

Thanks [Vikas] for sending in this tip.

What Can We Learn From a Cheap Induction Cooktop?

Sometimes tearing down a cheap appliance is more interesting that tearing down an expensive one. A lot of the best engineering happens when cost is an issue. You may not solve the problem well, but you can solve it well enough for a discount shelf.

[openschemes] purchased a 1.8kW induction hot plate at a low price off Amazon. The reasons for the discount soon became apparent. The worst of which was a fully intolerable amount of high frequency switching noise. Wanting to know how it worked, he took it apart.

After he had it apart on his desk, he deciphered the circuit, and wrote about it clearly. As usual with extremely cheap electronics, some clever hacks were employed. The single micro-controller was used for monitoring, and generated a PWM signal that was instantly converted to DC through some filters. All the switching was done the old fashioned way, which explained why the hotplate seemed so brainless to [openschemes] when he first turned it on.

Lastly, he did some work on manually controlling the cooktop for whatever reason. The good news? He managed to figure out how to control it. Unfortunately he also destroyed his unit in the process, via a misapplication of 1200 volts. A fitting end, and we learned a lot!

Thanks [David Balfour] for the tip!

The USB Type-C Cable That Will Break Your Computer

USB has been on our desktops and laptops since about 1997 or so, and since then it has been the mainstay of computer peripherals. No other connector is as useful for connecting mice, keyboards, webcams, microcontroller development boards, and everything else; it’s even the standard power connector for phones. The latest advance to come out of the USB Implementers Forum is the USB Type-C connector, a device with gigabits of bandwidth and can handle enough current to power a laptop. It’s the future, even if Apple’s one-port wonder isn’t.

Ground is red, V is Black. Photo: Benson Leung
Ground is red, V is black. Photo: Benson Leung

The cable of the future is, by default, new. This means manufacturers are still figuring out the port, and how to wire it up. You would think remembering ‘red = power, black = ground’ is easy, but some manufacturers get it so terribly wrong.

[Benson Leung] is a Google engineer who works on the Chromebook Pixel products, a huge proponent of the USB Type-C connector, and a very prolific reviewer of USB Type-C connectors on Amazon. The latest cable he tested destroyed his test equipment, including a $1500 Chromebook Pixel 2. How did a cable manage to do this? The manufacturer switched black and red.

The cable in question was a SurjTech 3M cable that has thankfully been taken down from Amazon. Swapping GND and Vbus weren’t the only problem – the SuperSpeed wires were missing, meaning this was effectively only a USB 2 cable with a Type-C connector. The resistor required by USB spec was the wrong value, and was configured as a pull-down instead of a pull-up.

This isn’t an issue of a cable not meeting a design spec. Ethernet cables, specifically Cat6 cables, have been shown to work but fail to meet the specs for Cat6 cables. That’s shady manufacturing, but it won’t break a computer. This is a new low in the world of computer cables, but at least the cable has disappeared from Amazon.

This is My 3D Printed Brain!

This hack is a strange mixture of awesome and ghoulish. [Andrew Sink] created a 3D printed version of his brain. He received a CD from an MRI session that contained the data obtained by the scan. Not knowing what to do with it he created a model of his brain.


Out of a number of images, some missing various parts of his head, he selected the one that was most complete. This image he brought into OisriX, a Mac program for handling DICOM files. He worked on the image for an hour dissecting away his own eyes, skull, and skin. An STL file containing his brain was brought over to NetFabb to see how it looked. There was still more dissection needed so [Andrew] turned to Blender. More bits and pieces of his skull’s anatomy were dissected to pare it down to just the brain. But there were some lesions at the base of the brain that needed to be filled. With the help of [Cindy Raggio] these were filled in to complete the 3D image.

The usual steps sent it to the 3D printer to be produced at 0.2 mm resolution. It only took 49 hours to print at full-size. This brain was printed for fun, but we’ve seen other 3D printed brain hacks which were used to save lives. How many people do you know that have a spare brain sitting around?