3D Printer Warning: Heating Plastic To High Temps is Not Healthy

via Hackaday

If you’ve ever tried to cut a piece of acrylic with a tool designed to cut wood or metal, you know that the plastic doesn’t cut in the same way that either of the other materials would. It melts at the cutting location, often gumming up the tool but always releasing a terrible smell that will encourage anyone who has tried this to get the proper plastic cutting tools instead of taking shortcuts. Other tools that heat up plastic also have this problem, as Gizmodo reported recently, and it turns out that the plastic particles aren’t just smelly, they’re toxic.

The report released recently focuses on 3D printers which heat plastic of some form or other in order to make it malleable and form to the specifications of the print. Similar to cutting plastic with the wrong tool, this releases vaporized plastic particles into the air which are incredibly small and can cause health issues when inhaled. They are too small to be seen, and can enter the bloodstream through the lungs. The study found 200 different compounds that were emitted by the printers, some of which are known to be harmful, including several carcinogens. The worst of the emissions seem to be released when the prints are first initiated, but they are continuously released throuhgout the print session as well.

Perhaps it’s not surprising that aerosolized plastic is harmful to breathe, but the sheer magnitude of particles detected in this study is worth taking note of. If you don’t already, it might be good to run your 3D printer in the garage or at least in a room that isn’t used as living space. If that’s not possible, you might want to look at other options to keep your work area safe.

Thanks to [Michael] for the tip!

Put Legs on Your Smart Speaker

via Instructables

Google Home, Amazon Alexa, Apple Siri, Microsoft Cortana, Samsung Bixby, today we are virtually surrounded by a crowd of digital assistants. These artificial personalities are deeply impressive from a technical standpoint but they have one glaring issue: despite the best efforts of their creators, t…
By: Toglefritz

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App note: How current and power relates to losses and temperature rise on inductors and transformers

via Dangerous Prototypes

Coilcraft’s app note on temperature rise due to losses on inductors and transformers. Link here (PDF)

Core and winding losses in inductors and transformers cause a temperature rise whenever current flows through a winding. These losses are limited either by the allowed total loss for the application (power budget) or the maximum allowable temperature rise.

For example, many Coilcraft products are designed for an 85°C ambient environment and a 40°C temperature rise implying a maximum part temperature of +125°C. In general, the maximum allowed part temperature is the maximum ambient temperature plus temperature rise. If the losses that result in the maximum allowed part temperature meet the power budget limits, the component is considered acceptable for the application.

Green LED Means GO For Supercon Badge Hacking

via Hackaday

In addition to great speakers and enlightening workshops at Supercon, we have an area set aside for attendees to hack on their conference badges. There is no prerequisite beyond having a badge and a willingness to get hands-on. From hardware beginners to professional embedded system developers, we welcome all skill levels!

The image above is a free-form LED light sculpture by [4C1dBurn], who had just learned to solder and this is how a new skill was put into practice. In the background is the badge hacking arena: 7 tables set up in a row with 6 seats per table. The doors opened at 9AM and almost all the seats were filled by 9:30AM. There’s a constant flow as people leave to attend a talk or workshop, and others arrive to fill the vacancy.

In our hardware hacking overview, we shared an example of an LED array controlled by badge using shift registers. Several badge hackers built on top of this idea. [X] is making a version for surface mount LEDs, and [macegr]’s variant incorporated an USB-to-serial adapter on board to reduce wire clutter. He calls it a “quality of life improvement” and we think it’s brilliant.


Any reduction in wire clutter can only help with the many glorious explosions of wires scattered about. This particular example is a work-in-progress by [carfucar] turning a badge into wireless remote for a large array of WS2812B LED strips.

Heeding our call to action in the hardware hacking overview, there are at least two efforts underway to add wireless communication capability to the badge. [Preston] is making good progress teaching a badge to talk to an AVR-IoT module. [morgan] and [Ben] are building a mesh network using ESP32s. If it gets up and running, they’ve brought a bunch of ESP32s to add more nodes to their network.

For the talks currently on stage, go to the Supercon event page and click “Livestream” in the upper right corner for the official live stream. Badge hacking will continue all through Supercon, parts of which will be visible through unofficial livestream of badge hacking from attendees like [X]’s robot [Sharon].

Geniatech Has Launched the New Pi-Inspired XPI-S905X Single Board Computer

xpi1.jpg

via Open Electronics

Geniatech has now launched the XPI family of single board computers that will allow closely follow Raspberry Pi 3 form factor while offering better performance and features. The company will start with XPI-S905X board powered by an Amlogic S905X quad core Cortex A53 processor @ 1.5 GHz with 4K HDR video playback and output capability. […]

OpenMV Cam H7: the Open Source MicroPython Powered Machine Vision Camera

via Open Electronics

The New OpenMV Cam H7 is an upgrade of the previous OpenMV Cam M7, replacing the STMicro STM32F7 micro-controller by a more powerful STM32H7 MCU clocked at up to 400 MHz and introducing removable camera modules for thermal vision and global shutter support. The OpenMv Cam aims at becoming a super powerful Arduino with a camera […]

Glowing mercury thyratrons: Inside a 1940s Teletype switching power supply

via Dangerous Prototypes

glowing-tubes

Ken Shirriff take a look inside a bulky DC power supply REC-30 rectifier, how it works and contrast it with a MacBook power supply:

We recently started restoring a Teletype Model 19, a Navy communication system introduced in the 1940s.14 This Teletype was powered by a bulky DC power supply called the “REC-30 rectifier”. The power supply uses special mercury-vapor thyratron tubes, which give off an eerie blue glow in operation, as you can see below.
The power supply is interesting, since it is an early switching power supply. (I realize it’s controversial to call this a switching power supply, but I don’t see a good reason to exclude it.) While switching power supplies are ubiquitous now (due to cheap high-voltage transistors), they were unusual in the 1940s. The REC-30 is very large—over 100 pounds—compared to about 10 ounces for a MacBook power supply, demonstrating the amazing improvements in power supplies since the 1940s. In this blog post, I take a look inside the power supply, discuss how it works, and contrast it with a MacBook power supply.

See the full post on Ken Shirriff ‘s blog.