A TENS device for transcutaneous electrical nerve stimulation wraps around the upper calf much like a wristwatch wraps around the wrist. Here are some of its operational secrets. A medical device called a Quell performs what’s called transcutaneous electrical nerve stimulation on the lower leg. This technique is said to relieve diabetic pain. None of […]
As part of a continuing series where we take perfectly good LED bulbs and turn them into junk, Design World Executive Editor Lee Teschler and Associate Editor Michelle DiFrangia analyze the circuitry and design techniques used in a 60-W equivalent bulb from HOME Ever Inc., a Chinese manufacturer. There are big differences in this bulb […]
GFCIs detect hazardous current paths to ground and ground-to-neutral faults. They are relatively simple but have circuit details that can be tricky to figure out. In this short video, we go through the main functions of the main GFCI controller chip and the sensors that let it detect fault currents of various natures.
GFCIs detect hazardous current paths to ground and ground-to-neutral faults. A teardown reveals they are relatively simple but have circuit details that can be tricky to figure out. Bathrooms, kitchens, and other rooms with access to water are required to employ ac outlets with ground-fault circuit protection. GFCIs disconnect the output if they sense a […]
Here is what the architecture of modern-day dual-speed Ethernet/Wi-Fi router looks like these days. TP-Link’s Archer C7 dual-speed wireless router delivers 1,300 Mbps over the 5 GHz band and 450 Mbps over the 2.4 GHz band. That should be enough bandwidth for HD streaming, online gaming and other bandwidth-intensive tasks. The idea behind using two […]
The Amazon Echo Dot is essentially the top portion of the Amazon Echo, but without the speaker underneath it. Eliminating the big speaker drops the price of the from $180 for the Echo to $50 for the Echo Dot. The Echo Dot does have its own speaker, but the speaker is comparable to what you […]
Our teardown of R2-D2 shows what’s inside this little droid with a big personality. One of the hot new toys released in advance of the new Star Wars movie is R2-D2 by Sphero, the same toymaker that developed the BB8 for the 2015 Star Wars sequel called The Force Awakens. As with the BB8, R2 […]
Apple recently came out with the Series 3 version of its watch. We can get an idea of how the Series 3 goes together from a teardown analysis of Apple’s earlier Sport model. The Sport model we analyzed has an aluminum case but the watch is also available in stainless steel. It measures about 39 […]
Ketra unapologetically charges $100 for its A20 LED bulb, and the bulb needs a controller to work. Here’s what you find inside the bulb that makes it worth the premium price. A tunable A20-style LED light bulb from Ketra, in Austin, Tex., may be the world’s most expensive classic LED bulb. It lists at about […]
We took a look inside an LED bulb from high-end lighting supplier Ketra to understand its super-neat abilities to change color temperature and dim down to zero light via wireless control or conventional light dimmer. We found a lot of interesting stuff inside the bulb.