Old Czech Telephone Teardown Is Beautiful Purposeful Art

April 18, 2023 by Lewin Day 16 Comments

The 20th century saw everything from telephones to computers become mainstream. Many of these devices were beautifully designed in the mid-century period, something that’s hard to say about a lot of today’s cheaper technology. [John Graham-Cumming] has shown us one exquisite example, with his teardown of a simple Czech telephone.

The model in question is a DS3600 telephone built by Tesla Stropkov in the early 1980s. Despite this, it’s a design that looks like it hails more from the 1960s based on its smooth curves and rounded features. It’s a rotary dial phone, though a push-button version was also produced.

Inside the phone is a simple single-sided PCB clearly marked out with a tidy silkscreen. The ringer and a few capacitors make up the bulk of the circuitry inside the base, along with the rotary dial. The handset itself plays host to most of the other componentry, including the mystery “WNB 068 hybrid circuit” which [John] couldn’t positively identify.

It’s great to get a look inside vintage hardware and see how things were done in yesteryear. It’s particularly funny to think about how simple telephones used to be in contrast to today.

[Thanks to Saint Aardvark for the tip!]

GaN Charger Teardown Reveals Value Of This New Technology

March 31, 2023 by Lewin Day 39 Comments

Every so often, a new technology comes along that offers a broad range of benefits over what we already have. Just as lithium-ion batteries have made nickel-cadmium cells boring and old hat, gallium nitride semiconductors are making silicon parts look unimpressive by comparison. [Brian Dipert] looked at what this means in a practical sense by tearing down a GaN phone charger.

The charger in question is a 30 watt USB-C charger produced by Voltme. It cost [Brian] just $10, as prices of GaN hardware have come down significantly as economies of scale have kicked in. The charger measures just 1.2×1.3×1.2 inches, and weighs only 1.5 ounces. That compact size is thanks to GaN semiconductors, which are able to run cooler at higher power levels than their silicon forebearers.

Cracking into the charger required levering open the case. The back panel came off with some work, revealing the mains terminals, which deliver AC power to the PCB inside via the case holding them in contact. Interestingly, the entire circuit inside is filled with an adhesive thermal goop, which helps pass heat from the hottest components to the charger’s case. [Brian] is able to guide us through the circuit, and he identified many of the major components. However, some of the markings on chips were beyond his research skills, and he asks any knowing readers to contribute their own information.

It’s interesting to see just what makes the high-powered compact chargers of today tick. Plus, it’s a hallmark of progress that what was once considered a wonder material can now be had in a $10 commodity phone charger from Amazon. How times change!

Three Way LED Bulb Gives Up Its Secrets

March 14, 2023 by Al Williams 18 Comments

You’ve probably seen three-way bulbs. You know, the ones that can go dim or bright with each turn of a switch. [Brian Dipert] wondered how the LED version of these works, and now that he tore one apart, you can find out, too. The old light bulbs were easy to figure out. They had two filaments, one brighter than the other. Switching on the first filament provided some light, and the second gave off more light. The final position lit both filaments at once for an even brighter light.

LED or filament, three-way bulbs have a special base. While a normal Edison-base bulb has the threaded part as the neutral and a center contact for the live wire, a three-way bulb has an extra hot contact ring between the threaded part and the center contact. Obviously, a compatible LED bulb will need this same interface, but will work differently inside.

Inside the LED, [Brian] found two rings of LEDs that took the place of the filaments. He was able to identify all the ICs and devices on the board except one, an MT7712S. If you can read Mandarin, we think this is the datasheet for it.

We weren’t sure what [Brian] would find inside. After all, you could just sense which contacts had voltage and dim the LEDs using PWM. It probably wouldn’t take any less circuitry. LED lighting is everywhere these days, and maybe they don’t all work the same, but you have to admit, using two strings of LEDs is reasonably faithful to the old-fashioned bulbs.

Sometimes LED bulbs are different depending on where you buy them. We were promised LED bulbs would never burn out. Of course, they do, but you can usually scrounge some LEDs from them.

That Cheap USB Charger Could Be Costly

March 10, 2023 by Al Williams 31 Comments

[Big Clive] picked up a keychain battery to charge his phone and found out that it was no bargain. Due to a wiring mistake, the unit was wired backward, delivering -5 V instead of 5 V. The good news is that it gave him an excuse to tear the thing open and see what was inside. You can see the video of the teardown below.

The PCB had the correct terminals marked G and 5 V, it’s just that the red wire for the USB connector was attached to G, and the black wire was connected to 5 V. Somewhat surprisingly, the overall circuit and PCB design was pretty good. It was simply a mistake in manufacturing and, of course, shows a complete lack of quality assurance testing.

The circuit was essentially right out of the data sheet, but it was faithfully reproduced. We should probably test anything like this before plugging it into a device, but we typically don’t. Does our phone protect against reverse polarity? Don’t know, and we don’t want to find out. [Clive] also noted that the battery capacity was overstated as well, but frankly, we’ve come to expect that with cheap gadgets like this.

This isn’t, of course, the first phone charger teardown we’ve seen. This probably isn’t as deadly as the USB killer, but we still wouldn’t want to risk it.

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German Air Force Surplus Teardown

February 23, 2023 by Al Williams 11 Comments

It isn’t clear to us how [mrsylvain59] came into possession of a late-model piece of military gear from the German airforce, but we enjoyed watching the teardown below anyway. According to the documentation, the thing has a huge price tag, although we all know that the military usually pays top dollar for various reasons, so we are guessing the cost of the parts is quite a bit less than the price tag.

We don’t think [mrsylvain59] was sure what the amplifier (verstärker is German for amplifier) does. However, we recognized it as an avionics box from a UH-1 helicopter. We aren’t sure of its exact function, but it is classified under “Automatic Pilot Mechanisms and Airborne Gyro Components.”

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Watch Sony Engineers Tear Down Sony’s VR Hardware

February 19, 2023 by Donald Papp 22 Comments

Teardowns are great because they let us peek not only at a product’s components, but also gain insight into the design decisions and implementations of hardware. For teardowns, we’re used to waiting until enthusiasts and enterprising hackers create them, so it came as a bit of a surprise to see Sony themselves share detailed teardowns of the new PlayStation VR2 hardware. (If you prefer the direct video links, Engineer [Takamasa Araki] shows off the headset, and [Takeshi Igarashi] does the same for the controllers.)

The “adaptive trigger” module responsible for the unique feedback.

One particularly intriguing detail is the custom tool [Araki] uses to hold the headset at various stages of the disassembly, which is visible in the picture above. It looks 3D-printed and carefully designed, and while we’re not sure what it’s made from, it does have a strong resemblance to certain high-temperature SLA resins. Those cure into hard, glassy, off-yellow translucent prints like what we see here.

As for the controller, we get a good look at a deeply interesting assembly Sony calls their “adaptive trigger”. What’s so clever about it? Not only can it cause the user to feel a variable amount of resistance when pulling the trigger, it can even actively push back against one’s finger, and the way it works is simple and effective. It is pretty much the same as what is in the PS5 controller, so to find out all about how it works, check out our PS5 controller teardown coverage.

The headset and controller teardown videos are embedded just below. Did anything in them catch your interest? Know of any other companies doing their own teardowns? Let us know in the comments!

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Anatomy Of A Fake CO2 Sensor

February 18, 2023 by Jenny List 44 Comments

The pandemic brought with it a need to maintain adequate ventilation in enclosed spaces, and thus, there’s been considerable interest in inexpensive C02 monitors. Unfortunately, there are unscrupulous actors out there that have seen this as a chance to make a quick profit.

Recently [bigclivedotcom] got one such low-cost CO2 sensor on his bench for a teardown, and confirms that it’s a fake. But in doing so he reveals a fascinating story of design decisions good and bad, from something which could almost have been a useful product.

Behind the slick color display is a PCB with an unidentified microcontroller, power supply circuitry, a DHT11 environmental sensor, and a further small module which purports to be the CO2 sensor. He quickly demonstrates with a SodaStream that it doesn’t respond to CO2 at all, and through further tests is able to identify it as an alcohol sensor.

Beyond the alcohol sensor he analyses the PSU circuitry. It has a place for a battery protection chip but it’s not fitted, and an error in the regulator circuitry leads to a slow drain of the unprotected cell. Most oddly there’s an entire 5 volt switching regulator circuit that’s fitted but unused, being in place to support a missing infra-red module. Finally the screen is an application-specific LCD part.

It’s clear some effort went in to the design of this unit, and we can’t help wondering whether it could have started life as a design for a higher-spec genuine unit. But as [Clive] says, it’s a party detector, and of little more use than as a project case and battery.

Need more dubious instrumentation? How about a magnetic field tester?

Continue reading “Anatomy Of A Fake CO2 Sensor” →