More people watched the Logan Paul vs. KSI fight on Twitch than on YouTube | Lrd12 Overload Relay

A fun read is the Boeing’s space station power system document that describes the DC power system on the ISS: http://www.boeing.com/assets/pdf/defense-space/space/spacestation/systems/docs/ISS%20Electric%20Power%20System.pdf

Yup, switched off but still plugged in, that way the case is still earthed. Assuming a sensible 3-pin plug, or whatever the hell they do in places with just 2.

Good safety design will deliberately include a point (usually mains input) at which the creepage clearance is lower than any other place on the circuit board. This almost guarantees a *predictable* result from an extreme over voltage event.

I think most people recommend having the PSU switched off at the wall. That way it should be pretty much safe, but there is still the other issue you mention.

I was tasked with doing this last week at work and spent considerable time researching the best/safest way to do it with consumer equipment. As far as I can see the best solution is to use one of the many 433MHz RF controlled power adapters (Watts Clever sell them for as little as $10 each) and use the same record/playback trick used to record TV remote IR signals and play them back with an Arduino. Unfortunately the project requirements changed and I didn’t get to actually implement it but I see no reason why it wouldn’t have worked. Apart from being very cheap (~20 per unit) it keeps the mains voltage completely isolated from everything else, which is particularly important from a liability perspective when you have to deliver the units to an external client.

Grip comfort/security is greatly aided by the deeply sculpted thumbrest on the camera’s back. Combined with the textured rubber used over the whole right half of the body, it provides a very secure gripping point for my thumb, and does a lot to make up for the small size of the front grip. The rubber coating also contributes to a feel of solid build quality, by damping the body vibrations that often make small and light cameras feel tinny or cheap.

Solar water heaters are nice. Sadly, when one gets far north, the sun isn’t a common sight during the cold parts of the year.

Actually most power panels I have worked on alternate phases as you go down the opposite rows, not one phase on each side, 240 breakers take up 2 breaker spaces on one side of the panel using alternate legs.

And this AC vs DC case when it comes to skin effect, is a reason for why some Data centers use DC distribution, as most server products uses switch mode power supplies and therefor has an internal bridge rectifier.

First rule of LO-TO: if you didn’t LO-TO it yourself it’s not! I will never EVER trust anyone to do a LOTO for me. If I’m to stick my hands into something dangerous the key to that lock on the switch is going to be in MY pocket!

My grandmother had a set of glass topped buffet serving tables where the glass top had a foil element sandwiched between the glass layers. They plugged right into the wall. No components other than the heating element, line cord, and a neon bulb to remind you it was plugged in. The element terminated with a couple of fused in copper rods threaded to take nuts. Got too hot to comfortably touch, but warm enough to keep your food hot. It should be within the capabilities of a glass/ceramics hobbiest with a kiln to sandwich a foil element between two pieces of glass and fuse the sandwich together.

Sonos also made another big promise last October: Google Assistant. The company has positioned the Sonos One as a smart speaker that will be assistant-agnostic and support multiple consumer favorites. It shipped with Alexa, AirPlay 2 will cover Siri (albeit from your iOS device and not the speaker itself), but Sonos hasn’t provided much of a status update on where the Google project is.