The end of Instagram as we know it is here | 220v Contactor Relay

15A is more like 1,500 times what’s required to kill you, depending on what part of your anatomy it finds to traverse.

One of the best demonstrations I’ve ever seen, was at the Dayton hamvention. DP&L (Dayton Power & Light) set up several short poles with standard 7200 to 220 center tap transformers. By back feeding the secondaries with 220 from the breaker box, they could energize the 7200 lines and began demonstration what happens when you encounter these wires with numerous items. Antenna masts, kite strings, and even a hot dog were used to show the immense power available, and the audience was always suitably impressed.

I was tasked with doing this last week at work and spent considerable time researching the best/safest way to do it with consumer equipment. As far as I can see the best solution is to use one of the many 433MHz RF controlled power adapters (Watts Clever sell them for as little as $10 each) and use the same record/playback trick used to record TV remote IR signals and play them back with an Arduino. Unfortunately the project requirements changed and I didn’t get to actually implement it but I see no reason why it wouldn’t have worked. Apart from being very cheap (~20 per unit) it keeps the mains voltage completely isolated from everything else, which is particularly important from a liability perspective when you have to deliver the units to an external client.

All this stuff makes me think it might be time to get a Faraday cage installed around my heart. Or maybe a big shunt from shoulder to shoulder.

We first saw this feature in Sony’s DSC-TX1 and DSC-WX1 in mid-2009. Since then, it’s been mimicked by other manufacturers, but none seem to do it as well as Sony. In Handheld Twilight mode, the camera captures up to 6 shots in rapid succession, micro-aligns them with each other, and then adds them all together. The net result is that you can hand-hold ridiculously long exposures and still get sharp results, with very low image noise to boot. Combine this with Sony’s SteadyShot image stabilization and sharp handheld photos at half-second exposure times are feasible.

There are lots of AC coils out there – in my parts bins I have AC driven relays, and AC solenoid valves. How do they work?

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.

I have pulled this hack in a pinch with specific pieces of test equipment, etc. (usually large power supplies) in non-residential settings but instead of having a snazzy box I would use one extension cord and my trusty Fluke and sort it out. In that application, the circuits were almost always dedicated (or near-dedicated), but in a residential setting, there are still many circuits that are rarely loaded much if at all, and I see this as working perfectly fine for those times.

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.

It would require a molded socket attached to an edge with a standard IEC polarized C7 connector. No exposed conductors anywhere. Could embed a green light for powered up and a red one for hot into the socket molding.

hmm, not sure why my comment went in the wrong place. looked like it was in the [ GuruBuckaroo] comment, when I pecked it in. The “unusual sensation” quip was spot on & funny!

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.