Is my appliance compatible with the Amazon Smart Plug? | 19mm Momentary Push Button

A few people made some useful design suggestions. I like the Power Integrations LNK switch suggestion for power. I’d also recommend looking at the SR086, which does the same thing — but it’s inductorless! That’s the chip I’m using for my ESP8266-based WiFi dimmer.

It should be mentioned that any of us that have been working in commercial/industrial settings should be familiar and certified under NFPA70E. This includes, but is not limited to, how to work as safe as possible with hazardous energy sources, what the proper protection is for various levels and what is considered “safe” (working distance, approach distance, protection level, etc).

▲ 同时本公司还专业从事老机组制氢系统的自动化改造维修保养和大修工作，在为国内外众多厂家的服务过程中，积累了极其丰富的安装、调试和运行的经验，为用户提供了系统的管理、运行及商务等各方面优质、及时、周到、热忱的服务。

There is a ton of great information online about almost every air conditioner available. You can find troubleshooting tips on manufacturer websites as well as message boards and blogs.

For all my complaining about the difficulty of tracking sports subjects and the dead-screen issue, though, the difference between these SLTs and other consumer-level DSLRs is little short of astonishing. It may not be a direct substitute for a Canon 1D Mark IV or Nikon D3s, but if you have a budget of under $1,000 and shoot any fast action at all, the Sony A55 and A33 are hands-down slam-dunk purchase decisions. At this point, there’s nothing else in the large-sensor segment of the digital camera market that remotely approaches their high-speed capture capabilities.

The only powertrain available to test was the new, higher-powered 2.0-litre hybrid, designed to offer eco-conscious buyers who like a bit more performance an alternative to the resolutely fuel- and CO2-focused 1.8-litre. Mated to a six-speed auto, there are two standout features: chiefly, that the link between the accelerator position, revs and actual performance are better matched than ever before, with the CVT-esque disconnect between them now greatly – if not entirely – reduced, and secondly that, so long as you are happy to let the gearbox run as an auto, rather than play with the mostly superfluous wheel-mounted paddleshifters and try to act out your inner F1 driver fantasy, there is strong, smooth performance on offer.

If you run a separate earth wire that is hard grounded at the sub and hard grounded at your house and nowhere in between. In this situation if you get a lightning strike at or near your house then the ground potential rises. This flows through the earth wire to the sub ground and can be a massive current, enough to make the network fail dramatically. This rise in ground potential can also be caused by other things such as a faulty insulator on an MV or HV tower (pylon) or pole. Even if insulators are good then you can still get this ground potential rise. You can easily measure it with a length of wire and two earth spikes, put one near a tower and the other a distance away and you can see a significant voltage. If you also have a separate wire called neutral running form the sub then the potential between that wire and the earth wire is unknown so you have a risk of lethal voltage between neutral and earth, a situation that is not expected and potentially extremely dangerous.

As you said yourself, low current. There is good reason to worry about mains power. The most common breaker is 15A, and that is about 15 times what is needed to kill you. It won’t trip right away either, unless it is so old and weak that it needs replacement anyhow.

Ok let’s assume you have a coated PCB that that doesn’t promote condensation, now unless you’re immersing your PCB in Argon, the flash over voltage is a function of the air it’s in. Unfortunately this calculation has many variables such as impurities in the air like smog (which cause condensation), altitude (which dictates how much moisture the air can carry), distance between traces (of course) and several others.

Most people posting seem to have three stories, I only have two. Hard to believe I learn faster than you all; I must have just forgotten the other times.

The best tip for buying a portable home generator: Don’t wait until the lights go out. Whether you live in a place at the mercy of snowstorms, hurricanes, heat waves or an outdated electric grid, a power outage can range from an annoyance to life-threatening.

As someone who started playing with electronics in the days of B+ in the 350VDC range with double that across the main xformer’s secondary, I was utterly appalled at the idea of tying myself to a hard ground when working with some of the newer (for the time) solid-state stuff that was coming out. We had a respect for high voltage then that is often missing these days, this article is an excellent reminder that this is still needed.