Power Management, Chapter 8: Power Management ICs | 25 Amp Circuit Breaker

Electric blankets have lots of testing to ensure they’re safely insulated from the user. They also don’t get nearly as hot. They also use too much power to economically run from a low voltage PSU.

I had three electrocutions with mains voltage in about one hour. It was a dark and stormy night, when I decided to try again building my own half-bridge SMPS which had tendency to explode whenever I plugged it in. It was made of two boards: one contained EMI filters, bridge, fuse and HV electrolytic capacitors, other had high-side controller, transistors, transformer and everything else. When another transistor decided that it would rather choose new Pope instead of working, I got a bit angry. I grabbed something to drink in kitchen, returned and grabbed the board in order to smash it against the wall. I forgot to unplug it first. Ouch. Half a hour later, it was still dark and stormy night, I attempted to fix an ATX supply. When I was grabbing something from behind of supply, I touched the board with my forearm. Supply was plugged, of course. Ouch. Half a hour later, yes, it was a dark and annoying night, I was still working on the ATX supply. I unplugged the supply and was inspecting the traces, my nose and lower lip brushed solder pads of those two big caps that were charged to ~320V. I went to bed with my face hurting…

The remote has a few buttons and LED for status. The LED reacts differently depending on the pool’s current mode, so connecting there not only gives you control but also allows you to provide some limited status. It isn’t going to let you monitor pump currents or anything exotic, but it is a simple place to gain access. Using the Arduino pulse input function makes it easy to sense if the LED is on, off, or blinking. Another sensor reads the water temperature. The controller makes it available, but it isn’t simple to read, so the project just reads the raw sensor voltage from the existing thermistor and computes the temperature.

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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 guess you missed my writing ignorant people doing stupid things People using a metal utensil to clear a jammed toaster isn’t unheard of but still there are no barriers to that. Perhaps there are bread toaster that use an enclosed heating element like many toaster ovens use, but my fairly new UL labeled toaster uses the same style of heating element hat been used for decades. That what you quoted was directed the the DIY individual more likely to come across something like this, not average John or Jane Doe.

It’s the other way around. Muscles and nerves respond to di/dt and not constant current. You can let go of DC but not AC because the continuous pulsing is how the nerves signal the muscle to contract.

While the Sony A33 and A55′s viewfinder display led to a bit of a learning curve for tracking fast action, its buffer-clearing speed is an ongoing issue. The A55 can capture shots with amazing speed, but once its buffer is filled, things slow down dramatically. The A33, for its part, has a smaller buffer, but it takes less time to clear. The most irritating point with the A55 was that it seemed to take forever before it would let me look at what I’d just shot. This is certainly more of an issue for a relatively inexperienced user than a pro sports photographer, but I often found myself wanting to check out what I’d just shot before the next action sequence started so I could note and correct for any problems in my shooting style. If I’d filled the buffer, though, it took upwards of 15-18 seconds before I could even view the first image on the LCD — and a good while longer before the buffer was completely empty and the camera was back to its maximum burst-length capacity. Shoot RAW+JPEG and it takes 32 seconds to clear a maximum of 18 images, while the A33 only captures 7 images and takes 12 seconds to clear. Advantage A33.

Seriously, it looks rather sparse inside, does it not? Perhaps some of you more electrically inclined/engineering types can chime in and let us know if $750 seems reasonable now that we know what’s inside?

This hack is ridiculous and a hazard. The NEC bans the use of MWBC’s that don’t use a common circuit breaker tie-bar. The tie-bar causes both halves of the 240VAC circuit to turn off incase of an overcurrent condition.

If you read carefully the related articles you will find that this module is mainly designed to switch lights aka lighbulbs. A 8A Triac is more than suitable to switch any standard household lamp. Please check the bigger one in your house. How big it is? 100W? 200W? 300W? Average value in probably in 99% of the cases between 40 to 100W. Anybody can to the math.

Alpha mount. The Sony A33 accepts Alpha-mount lenses from Sony, and is backward-compatible with older Minolta or Konica Minolta A-mount lenses, allowing use of a huge range of both current and historic glass. Compared to single-lens direct view cameras — even Sony’s own NEX series — this will likely make the Sony A33 a much more attractive proposition for existing Alpha or A-mount photographers. While Alpha-mount lenses can be used on NEX cameras through a mount adapter, they lose their in-body SteadyShot capabilities, whereas the Sony A33 retains this capability with the same lenses. (In an earlier version of this review, we also called attention to the inability to autofocus using Alpha-mount lenses on NEX-series bodies, but this looks to be negated by a forthcoming update for the LA-EA1 mount adapter that will enable Alpha-mount AF on NEX bodies. We’ve not yet tested this update, and hence can’t comment on how NEX and SLT-series cameras will compare in this area.) Sony rates the SteadyShot sensor shift mechanism in the Alpha A33 for between 2.5 and four stops of correction.