No high school diploma? You’ve got options! | 19mm Momentary Push Button

Yes, unfortunately, in my house the car isn’t in the basement. I work cheaper than most electricians, but nowadays they hardly do anything for $300. My Neighbor across the street paid for a 1/3 hp 110 volt outlet for his pool mandated by the town to be installed by a licensed electrician in this town, and it cost him $1400 for a simple direct buried UF 14-2 cable and a faceless ground fault on a dedicated 15 ampere circuit. That was more than the pool and filter. It would have been $1500 but he saved $100 by digging the trench himself..

Usually called a Residual Current Device (RCD) or Earth Leakage Circuit Breaker (ELCB). Usually set on 30mA, but they take a small time to trip, which is dependent on how much current is leaking into the poor unfortunate 3D printerer. Much better than nothing, but not 100% guaranteed to save your life. I’d sooner leave mains voltage alone for things I’m tinkering with. I only mess with the mains for simple jobs, and then I’m very cautious.

A steamy day on the flat roof of a building will let you feel how many inches the 480 can sting your fingers from also.

Australia is similar, except 3ph is uncommon in a house. There’s 3 phase at the kerb and each house is connected to one phase.

This seems to me that your experiment failed due to thermal failure cased by insufficient cooling and not the part itself..You stated yourself that the part failed due to thermal expansion (insufficient cooling). But it’s still a valid experiment with valid results. And you show that it’s up to the designer (or designers) to design the entire product, which includes sufficient cooling. This is one area where home designs fail – a lot.

Unfortunately, by in large, the comments for this article were unnecessarily negative, and downright factually inaccurate.

There is no mention of what powers the module here, and I suspect it is a regular 5V, isolated SMPS. @RobHeffo suggests transformerless power supply, but that is not a good idea, for the current drawn by the ESP the capacitor will be too big. There are alternatives, like this guy, LNK306 : http://www.mouser.com/ds/2/328/lnk302_304-306-179954.pdf . It is not isolated, but the thing is probably the best cost option for such a device.

There is a huge difference between heater and electric motor when it comes to inrush current. But anyway haven’t seen 600A contactor for switching on 60A motor.

In the old days, we were always careful to remind readers to purchase a second battery along with their camera, but in recent years, battery life has become much less of a concern than it once was. Not so with the Sony A33, though: Unless you intend it only for light snap-shooting, consider the purchase of a second battery mandatory.

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.

It is not enough to have the proper tools, you also have to use them in a safe way. The basic five rules go like this: 1. Disconnect from mains. 2. Secure against reconnection. 3. Verify that the system is really dead. 4. Perform earthing and short circuiting. 5. Provide protection from nearby live parts.

Upgrade the triac and redesign the PCB to be able to safely take a whole 2400W (Australian 240v 10A mains rating) of mains load.