Galaxy Users Accuse Samsung Of Throttling Performance And Benchmark Rigging

March 10, 2022 by 24 Comments

A lot of Samsung Galaxy users think that Samsung has been throttling smartphone performance, so much so that they don’t live up to their published specifications. At issue is the game optimizing service (GOS) which is intended to throttle the CPU while playing games to prevent overheating. S22 owners have recently discovered that it’s not only games that are throttled, but there’s a list of over 10,000 apps which are subject to GOS control, and there is no way to disable it.

What they’re really upset over is the fact that popular benchmarking apps are not subject to GOS throttling — something that’s hard to see as anything but a blatant attempt to game the system. In fact, this past weekend the folks at Geekbench banned four generations of Samsung Galaxy phones (S10, S20, S21, S22) for benchmark manipulation.

Admittedly, thermal management is critical on today’s incredibly powerful handheld devices, and the concept of throttling is an accepted solution in the industry. But people are upset at the opaqueness and lack of control of GOS, not to mention cherry picking apps in order to excel at benchmarks. Furthermore Samsung has removed their vapor chamber cooling system from recent models. This makes GOS even more important and looks like a cost-savings measure that may have backfired. Currently there’s a petition with the government claiming false advertising, and users are actively pursuing a lawsuit against Samsung.

Reflow Hotplate Teardown Uncovers The Bare Minimum

March 10, 2022 by 13 Comments

[EEforEveryone] is trying to find a good hot plate for reflow soldering. After trying one cheap unit, he got another one. He was a bit underwhelmed. The grounding was suspect and the bed wasn’t totally flat. He tore it apart and was surprised that there was very little inside. While the construction wasn’t perfect, it was better than the previous unit. You can see a video of the teardown and review below.

Before powering it up, the first order of business was to rewire the ground system. After that, it was time to try it. However, by confusing Fahrenheit and Centigrade, he set the temperature much higher than necessary which creating a little smoke. Fixing the temperature helped, but there was still a bit of a smoky smell that eventually subsided.

The verdict? The hot plate worked well enough, but you probably do want to check the ground wiring before using it. That’s often a good idea where cheap equipment is concerned, anyway. But the real takeaway is that it looks like you could homebrew something equivalent without much trouble. The controller is an off-the-shelf module. A switch and a plug aren’t hard to figure out. The heating element could be a silicone heater or PCB heater meant for a 3D printer.

Of course, there are other options. You could use a wok. Or why not a waffle iron? You can also make a custom PCB.

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The Fliegerfaust Roars Back To Life After 77 Years

March 9, 2022 by 36 Comments

As their prospects for victory in the Second World War became increasingly grim, the Germans developed a wide array of outlandish “Wonder Weapons” that they hoped would help turn the tide of the war. While these Wunderwaffe obviously weren’t enough to secure victory against the Allies, many of them represented the absolute state-of-the-art in weapons development, and in several cases ended up being important technological milestones. Others faded away into obscurity, sometimes with little more then anecdotal evidence to prove they ever even existed.

One of these forgotten inventions is the Fliegerfaust, a portable multi-barrel rocket rocket launcher designed for use against low-flying attack planes. Although thousands were ordered to defend Berlin in 1945, fewer than 100 were ever produced, and there’s some debate about how many actually survived the war. But that didn’t stop [Jonathan Wild] of Wild Arms Research & Development from building a functional replica of the weapon based on contemporary documentation and blueprints.

Building the launcher was relatively straightforward, as it’s little more than nine tubes bundled together with a handle and a simplistic electric igniter. The trick is in the 20 mm (0.78 inch) rockets themselves, which are spin stabilized by the exhaust gasses exiting the four angled holes on the rear. With no fins or active guidance the path of each rocket is somewhat unpredictable, but this was known to be true of the original as well.

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WebGPU… Better Than WebGL?

March 9, 2022 by 19 Comments

As the browser becomes more like an operating system, we are seeing more deep features being built into them. For example, you can now do a form of assembly language for the browser. Sophisticated graphics have been around using WebGL since around 2011, but some people find it hard to use. [Surma] was one of those people and tried a new method that is just surfacing to do the same thing: WebGPU.

[Surma] liked it better and shares a lot of information in the post and — oddly — the post doesn’t use WebGPU for graphics very much. Instead, the post focuses on using GPU cores for fast computation, something else you can do with WebGPU. If your goal is to draw on the screen, though, you need to know the basics and the post links to a site with examples of doing this.

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VFD Character Display Turned Into Audio VU Meter

March 9, 2022 by 8 Comments

Humans love visualising music, whether it’s in the form of an inscrutable equation drawing squiggles in Winamp, or a simple VU meter pulsing with the beat. This build from [mircemk] is of the latter variety, repurposing a VFD display to do the job.

The project is built around a VFM202MDA vacuum fluorescent display, which provides that lovely green-blue glow we all know and love, driven by a PT6314 driver chip. This has the benefit that it can be readily driven by a microcontroller in much the same way as the familiar HD44780 character LCD driver chip. With some minor tweaks, the character set can be modified to allow the display to become a surprisingly-responsive VU meter.

An Arduino Nano runs the show, with an envelope follower circuit feeding a signal for the left and right channels into the analog inputs of the microcontroller. The Arduino then measures the voltage on those inputs and feeds the necessary commands to the PT6314 driver to update the display.

The resulting VU meter has 38 bars per channel, and is highly responsive. The fast flickering of the meter bars in response to the music make it compelling to watch, and the era-appropriate enclosure the project is built in adds plenty to the aesthetic.

We’ve seen other VU meter builds before too, like this one that uses a little physics knowledge to create a more realistic analog-like needle meter. Video after the break.
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Building A Pendulum Clock Out Of Lego

March 9, 2022 by 10 Comments

Pendulum clocks aren’t used quite as often these days as their cumbersome mechanics and timekeeping abilities have long been outshone by electronic alternatives. However, they’re still fun and they do work, so [PuzzLEGO] set about building a working example with Lego.

The rear view reveals the escapement built from Lego Technic parts.

The core of the clock is the escapement, a linkage which the pendulum can only turn in one direction. As the pendulum swings once per second, it lets the escapement gear turn one notch forward at a time, turning the gears of the clock which drive the hands. It’s powered with a falling weight in the form of a drink bottle full of water, which turns the gears of the clock via a chain.

The clock can only run for approximately an hour, so it’s set up with a second and minute hand instead of the more usual minute and hour hand. However, with the pendulum tuned to the appropriate length and the weight fitted, it pleasantly ticks and tocks the seconds away.

We’ve seen other great builds from [PuzzLEGO] before, too, like this inventive Rubik’s Cube build. Video after the break.

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Class A Amplifiers, Virtually

March 9, 2022 by 21 Comments

If you didn’t know better, you might think the phrase “class A amplifier” was a marketing term to help sell amplifiers. But it is, of course, actually a technical description of an amplifier that doesn’t distort the input waveform because it doesn’t depend on multiple elements to handle different areas of the input waveform. Want to know more? [FesZ] has a new video covering the basics of class A amplifiers including some great simulations. You can see the video below.

A class A amplifier uses a transistor that is always biased on. It never saturates or switches off. This is good for linearity, but not always the best for efficiency so there are other classes of amplifiers, too. However, for many applications, class A is the most common configuration.

There are a number of trade-offs involved with each type of amplifier and [FesZ] covers them in detail. But the real interesting part is the simulations in Spice. Sure, you can build the circuits and look at everything with a meter or scope, but using Spice is much handier.

There is a second video upcoming. We hope he covers other amplifier types too, as you really do want to understand the differences when you need to design something. If you want more Spice stuff, check out some of our previous posts. If for some reason, you don’t like LTSpice, there’s always Micro-Cap 12.

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