Portable 120V to 240V Converter; or How to Fast Charge at Your In-Law’s House | 220v Contactor Relay

When I was a kid I built a Tesla coil using a 12kV neon sign transformer which my mom got for me (this was the 1960s, before Americans turned into wimps). At some point I had the transformer sitting on my workbench and plugged in, with nothing connected to the output. The corona discharge made a hissing sound, but I had music on and couldn’t hear it. Perhaps eight inches away was my table radio, which had a metal chassis. I reached between the two to get something, and my arm shortened the air path enough for an arc to form. I had a couple of nifty burn marks (entry and exit) for a few weeks.

Jerry is Mobile Nation’s resident nerd and proud of it. There’s nothing he can’t take apart, but many things he can’t reassemble. You’ll find him across the Mobile Nations network and you can hit him up on Twitter if you want to say hey.

I’m renovating my basement, and putting in a 240V line to my garage. Just for something to do, as I don’t have an EV.

inserts probes into amperge socket sets to VAC and measures 120v wall socket meter goes bang and lets blue smoke out

The triac can handle 8 amp continuously and upwards to 60 amps in surges. But the 8 amp is if heatsinked enough. If you insist on a 15 amp capability replace the triac with a 25-30 amp model instead. But will *still* need heatsinking. I triac usually drops upwards to 1 volt, so pushing 15 amps in a triac regardless of size will generate up to 15 watts, and that will generate a *lot* of head in a hurry.

[Ron] does a nice job of explaining some basic concepts like using opto-isolators. However, the real value to the video is the easy way to interface to the existing controller. A little configuration into Home Automation rounds out the project.

In some cases, contractors have stated that certain municipalities are requiring that conductors be sized based on the breaker size instead of the MCA. This is not uncommon, but it is usually a matter of a respectful conversation about the above NEC articles. The “authority having jurisdiction” or AHJ is responsible for interpreting the code, and they can make any standard they see fit. While certain local legislation may supersede the NEC with additional regulations, the NEC is a nationally recognized standard throughout the U.S. It is rare that a building department will ignore entire articles of the NEC when it is brought to their attention in a respectful manner.

You don’t need a 3D printer to use a heated print bed for 3D printing? I’d think that having the rest of the 3D printer would more or less be required to use a heated bed to facilitate printing.

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.

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.

Translucent mirror (redux). As noted previously, adopting a translucent mirror design has allowed Sony important benefits in terms of autofocus, burst shooting, and body size, and conceivably the removal of one more mechanical component could improve camera reliability, as well. There’s no such thing as a free lunch, though, and the translucent mirror design does have some clear disadvantages as compared to existing SLR and SLD designs. Perhaps most significantly, light entering the lens is shared between the autofocus and image sensors at a fixed ratio. In the Sony A33, about 70% of the light makes it to the imaging sensor, while 30% is reflected to the autofocus module. With a traditional SLR, all the incoming light arrives at the image sensor once the mirror is raised, and the same is true of an SLD camera whenever its shutter is open. With less light arriving at the sensor for an equivalent aperture, a translucent mirror camera must either lower its shutter speed, raise its sensitivity (and along with this, the levels of noise, or the amount processing to mitigate it), or some combination of both. An increase in sensor gain to compensate for the loss may explain why we see slightly higher noise levels from the A33 versus the A560, which share the same sensor.

The second upgrade to the Sony A33′s LCD is the TruBlack technology we first saw on other recent Sony cameras. This is a combination of anti-reflective coatings and a darker mask around the LCD pixels, to keep shadow areas darker. It does seem to be an improvement over LCDs lacking it, but to my eyes, the difference isn’t dramatic.