Bitcoin Futures Deliver Wild Ride as Debut Brings Rally, Halts | 25 Amp Circuit Breaker

This is very dangerous. Safety regulations are all about keeping mains voltage away from people, inside casings that are earthed or double-insulated. This has the voltage just lying there. Possibly covered with a bit of silk-screened paint. It’s not guaranteed to kill someone, but for the extra money I’d sooner have a non-deadly heater for a 3D printer.

Remember that, across the same resistance, power goes up with the square of voltage; 120v RMS can deliver 100x the wattage of a 12v supply, and 240v delivers 400x.

The theory side of PCB creepage clearnesses is useless because it assumes that there is one constant voltage that the circuit will run at when in reality it’s an over voltage event that usually causes failure, but here are the basics anyway.

Considering the existence of deep subzero freezers, it would still perform better than a resistive element. Or have it draw the heat from the indoors and run some crypto miners to make up for it.

Agreed…. I used to have a small plastic box in our workshop. It had two copper contacts on opposite surfaces, and a 9V battery, relay and tilt switch inside, and a Caution High Voltage sticker on it,

Personally, I would always design for the full rated power load of the outlet. Sure you will be aware of the limitations of the switch but not everyone reads the specs and you don’t want to blow up your switch when someone inadvertently plugs in a vacuum cleaner.

An emergency isolation switch. Santeri Viinamäki [CC BY 3.0], via Wikimedia CommonsYou will be familiar with emergency isolation switches if you have worked with large machine tools. A big red switch designed to be easy to hit to turn all the power off. You may want to hit it if something gets out of hand, or someone else may want to hit it for you to turn off the power that is electrocuting you. Either way it provides a very quick way to manually make any mains sources on your bench as safe as possible in the event of an incident. Remember the bit we mentioned earlier in about sitting on the end of the line twitching until the power is turned off? This is the big red switch that makes it very easy for someone to do that for you.

Over and over again, I have heard HVACR technicians and electricians quote rules of thumb regarding wiring sizing, and I have witnessed and participated in many heated debates on the topic.

The issue with the DC heated beds seems slow temperature rise. Some bigger builds and beds need a quicker heatbed heater. (In my opinion not needed for PLA) Only for ABS.

It’s also worth noting that some of the quibbles, such as wind noise and the slightly fidgety ride, are still being worked on. What appears to be a good car could yet get even better.

Once you’ve  established these ground rules you can then tailor your approach based on a realistic expectation of the risk involved. This process might seem rather long-winded, but in practice it should only require a moment’s thought. It’s infinitely better to take that moment to think than get an unexpected and possibly lethal high-voltage electric shock.

I don’t use my infrared camera as a quantitative tool; I use it as a qualitative tool. Yeah, I know, more blowhard words. Put simply, I’m not too concerned with the exact temperatures that are displayed on my infrared camera. As a home inspector, what I’m concerned with and what I dig into are the meanings behind unexpected temperature differences, aka anomalies.