Sega pushes the Mega Drive Mini global release to 2019 | 19mm Momentary Push Button

> and some apartments are fed with 208V 3-phase, which provide three phases of 120V to neutral, or 208V phase-to-phase.

Second was with an old (illegal) CB amp that I was converting to HF, and I touched an unshielded feed inductor of some sort, the aftermath from the RF burn was worse than that time I grabbed the wrong end of an iron with my fingers.

You probably knew that, so I apologize if I’m going over familiar ground, but for others, it’s worth mentioning.

Five vs Ten amps is a big difference in heating in the power factor correction circuit of his power supply. If you find a data sheet for similar power supplies, they are always 1-3% more efficient on 220Vac and run cooler because of it.

Thanks for the pointer, it looks promising! The RF-controlled remote switch appliances that can be found for a few dollars are self-contained, I would think that a Wifi-based one could also be? Having a separate wire coming out of the box seems like an extra hazard to me. If you keep the thing self-contained with only mains-in/mains-out, I would think it is safer in the end, and removes the internal complexity of optocouplers.

Mains powered heated glass plates are common place in catering, same deal as a car back window, the heating wires are on the other side from the “working surface” these things can tolerate touching and even fluid spills, why reinvent the wheel, the solution is already commercially avaliable.

https://en.wikipedia.org/wiki/Extra-low_voltage >Extra-low voltage (ELV), in electricity supply, is one of several means to protect against electrical shock. The International Electrotechnical Commission and its member organizations define an ELV circuit as one in which the electrical potential of any conductor against earth (ground) is not more than either 25 volts RMS (35 volts peak) for alternating current[inconsistent], or ripple-free 60 volts for direct current under dry conditions.

Knocking over a candle would be an accident. Keeping barrels of petrol in your living room would be negligence. Doing your own mains wiring without the proper qualifications, I dunno which side that falls on. Real accidents can’t be foreseen, but you have to take reasonable precautions.

Take a look at the Lennox air conditioning condensing unit tag on Page 19. Notice that the MCA is 28.6 amps and the maximum fuse or circuit breaker is 50 amps. This means it is allowable to install this unit on a circuit breaker rated at 50 amps and a conductor rated at 28.6 amps, according to the NEC’s NFPA 70.

Think for a minute, what are you going to find inside that box? You need to consider what voltages it takes as a power supply, what it does with those voltages, where any hazardous voltages might lie inside it, and whether or not they are likely to be accessible once the cover is off. It’s important to realise that simply because an item isn’t mains-powered does not mean you no longer have to consider this, for example if you’ve ever opened a camera with a built-in flash you may have encountered a capacitor with several hundred volts remaining on it. Where is the high voltage going to be?

Of course in many parts of the world that’s not possible like it is here in the US where better than 60% of homes have access to NG

MLVs come in various chip form sizes, and are capable of dissipating significant surge energy for their size. Thus, they suit both data-line and power-supply transient-suppression applications.