The Expanse is being turned into an RPG | 220v Contactor Relay

And this AC vs DC case when it comes to skin effect, is a reason for why some Data centers use DC distribution, as most server products uses switch mode power supplies and therefor has an internal bridge rectifier.

Yes, agreed, actual power supply design must take into account the allowable possible range of input. My house nominal “240V” supply routinely hits 252V, for example, and is allowed to go as high as +6% (254V).

It works, but the losses are significantly higher, and if you’re drawing much power you’re going to need heavy, expensive low-voltage sides on both transformers. In a pinch, fine, but if you’re going to be buying them it’s better to spring for a single transformer.

The third apartment I ever rented had ungrounded two-prong outlets in the kitchen, and rather than do the old 3-prong-adapter route for the microwave (the good ones with a green wire to the center screw), I said, “let’s replace the outlet,” I switched the breaker, verified that there was no power with a lamp, and started disassembly…. and the screwdriver arced, Most likely the breaker was on the neutral instead of the hot or something stupid like that. I did one of those “cat with octopus on his face” nope nope nopes, and *carefully* reassembled everything and fetched the darn 3-prong adapter.

With the large kossel build a mains heated bed is used. The mini kossel build used a reflective surface under the heated plate, a bit heath robinson, that it is used on the new larger build is good, heat is reflected up into the bed, lt worked well on the Mini Kossel.

The stakes are much higher when you’re connecting your project to the house mains, though, as [Mattias Wandel] recently learned when the solid-state relay controlling his water heater failed, with nearly tragic results. With aplomb that defies the fact that he just discovered that he nearly burned his house down, [Mattias] tours the scene of the crime and delivers a postmortem of the victim, a Fotek SSR-25DA. It appears that he mounted it well and gave it a decent heatsink, but the thing immolated itself just the same. The only remnant of the relay’s PCB left intact was the triac mounted to the rear plate. [Mattias] suspects the PCB traces heated up when he returned from vacation and the water heater it was controlling came on; with a tank full of cold water, both elements were needed and enough current was drawn to melt the solder build-up on the high-voltage traces. With the solder gone, the traces cooked off, and the rest is history. It’s a scary scenario that’s worth looking at if you’ve got any SSRs controlling loads anywhere near their rated limit.

“180 bolts per second”? Now there’s an engineering unit I’ve never encountered in more then 50 years. No, it’s just a 150-180 volt sinusoidal or square wave at various frequencies. In past years, the coil on the bell was mated to an appropriate capacitor to allow ringing a specific phone on a “party line” based on the ring frequency. It was amazing stuff for a time when they simply hadn’t run enough wires for all of the individual “private lines”, so they had to engineer very basic things to fill the need. It was in a sense, the most basic and pure form of understanding the physics (electrical and mechanical) hacking.

All in all, the current draw through this device was below it’s “rated” value. So either it’s a fake/poorly produced or was simply defective.

仲鑫达以“专业、 诚信、创新、合作、共赢”的经营理念、不断开发新产品、为客户提供优质服务、以最大限度追求客户满意、并不断开拓新领域业务。

On top of this, if we halve the current, then we can also use thinner and therefor cheaper wires in our power distribution system.

All electrical devices are designed with safety in mind and are rigorously tested to make sure the design works. All of us have probably plugged in one too many things on the same circuit and tripped a breaker or blown a fuse, and that’s the first consideration you need to know about the Amazon Smart Plug — it has a safe output rating based on the type of load you’re using. Here are the exact technical specifications according to Amazon.

If I find a warm circuit breaker, I take a logical approach. First, is there a good reason for the circuit breaker to be warm? A 240-volt appliance like an air conditioner will definitely warm up a circuit breaker while it’s operating. No problem there. The image below shows a warm circuit AC circuit, but in this case, I do care about the temperature readings. This circuit is only about 8 degrees warmer than anything else in the image. This is not a significant difference, and it makes sense.