Have LED Bulbs Reached Their Final (and Cheapest) Form?

February 16, 2020 by Donald Papp 129 Comments

[electronupdate] has done a lot of LED light bulb teardowns over the years, witnessing a drive towards ever-cheaper and ever-simpler implementations, and suspects that LED light bulb design has finally reached its ultimate goal. This teardown of a recent dollar store example shows that cost-cutting has managed to shave even more off what was already looking like a market saturated with bottom-dollar design.

The electrical components inside this glowing model of cost-cutting consists of one PCB (previously-seen dollar store LED bulb examples had two), eleven LEDs, one bridge rectifier, two resistors, and a controller IC. A wirewound resistor apparently also serves as a fuse, just in case.

Inside the unmarked controller IC. The design is as cheap as it is clever in its cost-cutting.

That’s not all. [electronupdate] goes beyond a simple teardown and has decapped the controller IC to see what lurks inside, and the result is shown here. This controller is responsible for driving the LEDs from the ~100 Volts DC that the bridge rectifier and large electrolytic cap present to it, and it’s both cheap and clever in its own way.

The top half is a big transistor for chopping the voltage and the bottom half is the simple control logic; operation is fast enough that no flicker is perceived in the LEDs, and no output smoothing cap is needed. The result, of course, is fewer components and lower cost.

Some of you may recall that back in the early days of LED lighting, bulbs that could last 100,000 hours were a hot promise. That didn’t happen for a variety of reasons and the march towards being an everyday consumable where cost was paramount continued. [electronupdate] feels they have probably reached that ultimate goal, at least until something else changes. They work, they’re cheap, and just about everything else has been successfully pried up and tossed out the door.

Solving The Mysteries Of Grounding While Improving A Power Supply

February 4, 2020 by Bryan Cockfield 22 Comments

Grounding problems and unwanted noise in electrical systems can often lead to insanity. It can seem like there’s no method to the madness when an electrical “gremlin” caused by one of these things pops its head out. When looking more closely, however, these issues have a way of becoming more obvious. In a recent video, [Fesz Electronics] shows us how to investigate some of these problems by looking at a small desktop power supply, modelling it in LTSpice, and reducing the noise on the power supply’s output.

While everything in this setup is properly grounded, including the power supply and oscilloscope, the way the grounding systems interact can contribute to the high amount of noise. This was discovered by isolating the power supply from earth ground using electrical tape (not recommended as a long-term solution) and seeing that the noise was reduced. However, the ripple increased substantially, so a more permanent fix was needed. For that, the power supply was modelled in LTSpice. This is where a key discovery was made: since all the parts of the power supply aren’t ideal, noise can be introduced from the actual real-life electrical behavior of some of the parts. In this case, it was non-ideal capacitance in the transformer.

According to the model, this power supply could be improved by adding a larger capacitor across the output leads, and also by increasing their inductance. A large capacitor was soldered in the power supply and an iron ferrule was added, which decreased the noise level from 100 mV to around 20. Still not perfect, but a much needed improvement to the simple power supply. If, on the other hand, you want to make sure you eliminate that transformer’s capacitance completely, you can always go with a transformerless power supply. That carries other risks, though.

Continue reading “Solving The Mysteries Of Grounding While Improving A Power Supply” →

Pavlok Gets A Literally Shocking Teardown

February 2, 2020 by Tom Nardi 36 Comments

Apparently, there is a wrist-mounted device that delivers electric shocks to the wearer when it receives the appropriate command over Bluetooth. No, it’s not part of some kind of house arrest program. If you can believe it, the gadget is actually intended to help break bad habits or wake up exceptionally deep sleepers. We don’t know which of those problems [Becky Stern] has, but we’re glad to see she decided to take hers apart before the 21st century self-flagellation started.

Called the Pavlok and available for $180 USD from various online retailers, the device looks like a chunky fitness tracker. But in place of the screen that would show you how many steps you’ve taken or your current heart rate, there’s a lighting bolt button that you can press when you want to shock yourself. With the smartphone application, you can control the device remotely with a handy desktop widget that allows you to select the intensity of the shock. No, we aren’t making any of this up. Check out the video after the break to see it in action.

When [Becky] tried to take the Pavlok apart, she found that it was nearly impossible to handle it without inadvertently triggering a shock. So until she could get the case open and physically disconnect the battery, all she could do was turn the intensity down in the application and work through the occasional jolts from the device. We can only hope that more devices don’t adopt a similar sense of self-preservation.

Once inside she found mainly the same kind of hardware you’d expect in a standard, non-masochistic, fitness wearable. There’s a nRF52832 Bluetooth SoC, a MMA8451Q accelerometer, a PCF85063A I2C RTC, and a FXAS21002C gyroscope. What you’re somewhat less likely to find inside your FitBit however is the LPR6235 coupled inductor and beefy capacitors which are used to build up a high-voltage charge from the standard 3.7 V LiPo battery.

We’ve been very interested in the recent projects which are creating custom firmwares for commercially available fitness wearables, as it could be an express route to a hacker-friendly smartwatch. While the Pavlok has some compelling hardware, and the programming header [Becky] identified looks interesting, we don’t like the idea of being one misplaced if statement away from riding the lightning.

Continue reading “Pavlok Gets A Literally Shocking Teardown” →

Retrotechtacular: Teasmade

January 30, 2020 by Jenny List 70 Comments

We’re used to our domestic appliances being completely automated in 2020, but not so long ago they were much simpler affairs. Not everything required a human to run it though, an unexpected piece of electromechanical automation could be found in British bedrooms. This is the story of the Goblin Teasmade, an alarm clock with a little bit extra.

Continue reading “Retrotechtacular: Teasmade” →

Carbide3D Router Teardown And Testing

January 27, 2020 by Al Williams 6 Comments

On the face of it, you’d think a small router would be pretty simple. After all, what is it other than a spinning motor? However, that motor has to handle some pretty serious torque depending on what you are routing. [Baki1] had his Carbide3D router die in the middle of a project, so he did what any of us would do. He tore it open.

In addition to showing off its insides, he also tried to figure out what was wrong with it. It looks like a blown triac was the culprit, and we assume that part 2 will be the repair and how that actually worked out.

Continue reading “Carbide3D Router Teardown And Testing” →

Form 3 SLA Printer Teardown, Bunnie Style

January 21, 2020 by Donald Papp 15 Comments

[Bunnie Huang] has shared with all of us his utterly detailed teardown on the Form 3 SLA printer from Formlabs (on the left in the image above) and in it he says one of the first things he noticed when he opened it to look inside was a big empty space where he expected to see mirrors and optics. [Bunnie] had avoided any spoilers about the printer design and how it worked, so he was definitely intrigued.

Not only does the teardown reveal the kind of thoughtful design and construction that [Bunnie] has come to expect of Formlabs, but it reveals that the Form 3 has gone in an entirely new direction with how it works. Instead of a pair of galvanometers steering a laser beam across a build surface (as seen in the Form 1 and Form 2 printers) the new machine is now built around what Formlabs calls an LPU, or Light Processing Unit, which works in conjunction with a new build tank and flexible build surface. In short, the laser and optics are now housed in a skinny, enviromentally-sealed unit that slides left and right within the printer. A single galvo within steers the laser vertically, as the LPU itself moves horizontally. Payoffs from this method include things such as better laser resolution, the fact that the entire optical system is no longer required to sit directly underneath a vat of liquid resin, and that build sizes can be bigger. In addition, any peeling forces that a model is subjected to are lower thanks to the way the LPU works.

Details about exactly how the Form 3 works are available on Formlabs’ site and you can also see it in action from a practical perspective on Adam Savage’s Tested (video link), but the real joy here is the deeply interesting look at the components and assembly through the eyes of someone with [Bunnie]’s engineering experience. He offers insights from the perspective of function, supply, manufacture, and even points out a bit of NASA humor to be found inside the guts of the LPU.

[Bunnie] knows his hardware and he’s certainly no stranger to Formlabs’ work. His earlier Form 2 teardown was equally detailed as was his Form 1 teardown before that. His takeaway is that the Form 3 and how it works represents an evolutionary change from the earlier designs, one he admits he certainly didn’t see coming.

Teardown: BilBot Bluetooth Robot

January 20, 2020 by Tom Nardi 16 Comments

Historically, the subject of our January teardown has been a piece of high-tech holiday lighting from the clearance rack; after all, they can usually be picked up for pocket change once the trucks full of Valentine’s Day merchandise start pulling up around the back of your local Big Box retailer. But this year, we’ve got something a little different.

Today we’re looking at the BilBot Bluetooth robot, which over the holidays was being sold at Five Below for (you guessed it) just $5 USD. These were clearly something the company hoped to sell a lot of, with stacks of the little two-wheeled bots in your choice of white and yellow livery right by the front door. With wireless control from your iOS or Android device, and intriguing features like voice command, I’d be willing to bet they managed to move quite a few of these at such a low price.

For folks like us, it can be hard to wrap our minds around a product like this. It must have a Bluetooth radio, some kind of motor controller, and of course the motors and gears themselves. Yet they can sell it for the price of a budget hamburger and still turn a profit. If you wanted to pick up barebones robotics platform, with just a couple gear motors and some wheels, it would cost more than that. The economies of scale are a hell of a thing.

Which made me wonder, could hackers take advantage of this ultra-cheap robot for our own purposes? It’s pretty much a given that the software for this robot will be terrible, and that whatever control electronics live inside it will be marginal at best. But what if we write those off and just look at the BilBot as a two-wheeled platform to carry our own electronics? It’s certainly worth $5 to find out.

Continue reading “Teardown: BilBot Bluetooth Robot” →