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We recently had a chat among the Hackaday writers about how we could approach this subject. The easy way out is to be all Elf-and-Safety and join the radioactive anthrax crowd. But the conclusion we came to was that this site is a resource for hackers and makers. Some of you are going to lift the lid on boxes containing significant voltages no matter what, so we thought we’d help you do it safely rather than just listen for the distant screams.

220 volt +/- 10% isn’t really a good design standard. As it doesn’t live up to the requirements within the EU to start with.

Electricity is complicated and dangerous. If you don’t know what you’re doing, you could start a fire or get electrocuted—sometimes fatally. Pretty much anything beyond plugging something into the wall should be left to a professional. The cost of my visit is nothing compared to the price of your safety. Here are 12 more home improvement projects you should never DIY.

My son replaced a C-Max with the regular hybrid version of a Niro recently. I would not use “reliable” and C-Max in the same sentence as it needed a new transmission at 77K miles (fortunately covered under a hybrid warranty), had a leaking engine (not covered under warranty), a Sync system that failed twice (covered under a special warranty extension that was about to expire), and numerous other problems mostly electrical in nature. We’ll see about the long-term reliability of the Kia but fuel economy has been in the high 40s (versus 35 for the C-Max) and all-around the Niro just feels like a much nicer car for less money. Personally I will definitely take a look at the plug-in version when I am next looking for a new car and it would be in the color of the one reviewed here so I hope it doesn’t get discontinued as Kia seems to like to do fairly often.

One quirk of the design of the Sony A33 (and shared by the A55) unfortunately conspires to make this high-speed burst shooting somewhat harder to use than would otherwise be the case. For both the ultra-speedy Continuous Priority AE mode, and the six frames per second Continuous Advance Hi mode, the live view isn’t shown on the viewfinder or LCD panel. Instead, the A33 shows the previously captured image. This makes it harder to follow fast-moving action, since rather than seeing what’s you’re trying to frame, you’re effectively seeing a static slideshow of what happened around a tenth of a second earlier. This problem, incidentally, is also found on all of the SLD’s we’ve reviewed. The Continuous Advance Lo mode, which shoots at around 2.5 frames per second on the A33, does return to the live view between shots, but only briefly — so it can still be a little hard to follow.

Since GM was having troubles with said DOPES regarding the 2011 VOLT, they quickly redesigned the current and all future units to have an AWG #14 connector cord, while keeping the AWG #16 connector cord to the car – why? – so that the oversized connector cord would extract heat from any overheating defective receptacle.

The basic concept of your point is looney. Voltage doesn’t cause heat, The only thing heat dependent for a given installation is the current – of which 120 volt charging is usually less than 240.

I can’t remember the exact numbers, but before the change, UK mains voltage was acceptable between something like 210V and 270V, depending on grid load. EU mains had a similar range. All they did, was tighten up the range. So now it’s nominally 230V, with 240V being within acceptable range. Which is good because the voltage stayed exactly the same. They just trimmed the range at the top end to be within the EU standards.

I think Brian’s point was that if the bond between the earth ground and the neutral return of the incoming premises power isn’t good enough, then the short to earth might *not* trip the breaker. Of course, it would likely start a fire instead (the resistance may not be zero, but it will be low enough to sink a great deal of power in most cases and a 15A breaker will tolerate a couple THOUSAND watts), but I think that if you can’t trust that the building is to code, then all bets are off.

The one negative that most stands out in my mind for the Sony A33 actually has the least to do with its abilities as a camera. The first thing that comes to mind when thinking about shooting with it isn’t whether I’ll be able to bring back the shots I want with it, but rather whether the battery will last long enough to do so. We have no doubt that the Sony A33 will meet the fairly generous shot-life numbers quoted under the CIPA specs (340 shots with the LCD, 270 with the EVF), but in actual practice, with the camera rattling off hundreds of shots in amazingly short order, what most struck me was just how fast I seemed to run out of battery life. It’s quite easy to run through a full battery in just a couple of hours of active shooting, and two batteries should be considered a minimum for a day of serious shooting.

It’s probably worth at this point explaining for a minute how earthing works with respect to mains power. You will have a local earth connection at your house, and your utility company will connect the neutral line to an earth at the substation to ensure that line voltages are not induced at a higher voltage with respect to their surroundings than the voltage they are supposed to carry. There may be 110V or 230V between the live and the neutral depending where you live, but without that earth connection both of those conductors could end up at thousands of volts higher than their surroundings, for example in a thunderstorm. The earth connection provides a fixed relationship between line voltage and the surroundings, such as the utility poles, trees, your house, and you.

You don’t need a big contactor to switch 1A at 120v, you can get little “ice cube” relays that switch up to 10A at 120V and they have a plug-in base so easy to change out when they inevitably fail. Most of them, in new perfect condition, make barely any sound. Nothing compared to the noise of fans and stepper motors. The only issue I can see is running AC mains voltage through wiring that is going in parallel with low voltage. Would need to use thick jacketed, shielded cable to prevent too much EMI. Maybe it’d be better suited using a separate transformer just for the heated bed, rectified/regulated but still a higher voltage for better efficiency. Speaking just from my experience as an electrician and hobbyist level electronics/3d printing experience.