This robot uses AI to find Waldo, thereby ruining Where’s Waldo | Lrd12 Overload Relay

You likely encountered a shared neutral between more than one circuit. You have to switch off the breakers for all the circuits that share the neutral.

The net result is that, while the Sony Alpha A33 is a fair bit thicker front-to-back than single-lens direct-view (SLD) cameras, which can do away with the bulky mirror box entirely, it’s still an exceptionally small camera by SLR standards. If the handgrip depth is ignored, the Sony A33 is actually just a little smaller than the smallest digital SLR to date, the Olympus E-420. Unlike the smallest SLD cameras, the A33 still includes a built-in electronic viewfinder — and for those SLDs that can accept an optional electronic viewfinder, much of their size advantage over Sony’s SLT-series models is erased once it’s installed. Sony’s A33 thus occupies a comfortable middle ground, sacrificing little of the versatility of a traditional SLR, yet bringing a worthwhile advantage in portability.

You need to factor in the kWh you used within the week (along with the cost per kWh). This will give people a better idea of actual cost to power this vehicle 253 miles.

I don’t know about anywhere else, but in North America, power enters the home via two 120V hot and one neutral. The two 120V hot legs are out of phase with each other, and when combined, you get 240V. So, from the breaker panel, you can pull 120V or 240V, depending on the type of breaker you insert at a given position. Some large appliances (water heaters, central AC units, electric stoves, large power tools) are 240V in North America, but most everything else is designed for a single leg 120V feed. Then just to make things even more complicated, large industrial businesses often have three phase 480V for the really big equipment.

I was in sixth or seventh grade, playing with a transformer with a 540 V secondary, when I accidentally grabbed one cllp lead too many. The current was flowing from one hand to the other, and I could not let go. Eventually–I’m sure the subjective time was much greater than the actual time–I was able to use my legs to knock myself off of the lab stool onto the concrete floor. Hitting the floor felt so good!

You don’t need a 3D printer to use a heated print bed for 3D printing? I’d think that having the rest of the 3D printer would more or less be required to use a heated bed to facilitate printing.

The earth ground connection won’t prevent you from being shocked unless it’s a GFI outlet. The soil resistivity in most places in the US doesn’t cause enough current to flow to earth ground to trip a normal breaker. Bonded ground systems are better, but if the bond from neutral to earth ground is far away from the short it might still not trip a normal breaker.

This is very dangerous. Safety regulations are all about keeping mains voltage away from people, inside casings that are earthed or double-insulated. This has the voltage just lying there. Possibly covered with a bit of silk-screened paint. It’s not guaranteed to kill someone, but for the extra money I’d sooner have a non-deadly heater for a 3D printer.

LOL– I stepped into doo-doo deep enough to over top chest waders, I’m over six feet tall, so that’s deep doo-doo. First I was surprise to learn that the heated beds weren’t heated by line voltage, IMO that’s a no brainer. Appliances across the word use line voltage to produce heat with no shock hazard present when use properly. Getting back to the deep doo-doo. Hackaday does present instruction posts. Line voltage is useful resource that is avoided because of irrational fear. I’m calling irrational because the fear is due to ignorance. I suggest Hackaday create instructional post on how to use line voltage in a way that’s safe to life and doesn’t cause property damage when something goes wrong. Peer reviewed studies and guidelines information is preferred.

There’s one more multi-shot feature on the Sony A33 that’s worth mentioning; namely Auto HDR (High Dynamic Range). HDR photography increases the range of brightness values represented in a scene by combining two or more shots taken at different exposures, combining highlight detail from some and shadow detail from others. In the past, this has involved locking the camera down on a tripod, shooting several images at different exposures, and then working on a computer to combine them. Lately, though, the capability to do this directly in-camera has been appearing from a number of manufacturers, with varying levels of success. The auto HDR feature on the Sony A33 works pretty well, since the camera does the same micro-alignment trick it uses for its other multi-shot features. Options for HDR include an Auto setting, where the camera determines how much of the effect to apply, and manual settings ranging from 1 to 6(!) EV of exposure range.

Also power the unit directly from the mains ( http://ww1.microchip.com/downloads/en/appnotes/00954a.pdf ) with the ability to power the unit directly with DC when (re)programming the ESP8266

I can see the benefit of inspection, I guess (that none of your wires popped off or something?). My comment on the relays was not that they were unsuitable, but that using the 240v coil as a 240v detector may or may not be entirely reliable because of holding vs. draw-in currents, box getting dropped, etc. although that’s edge-case engineering to an excessive degree and it really is perfectly fine.