Feeling The Heat Of High-Frequency Trading

It’s high summer here in North America, and for a lot of us, this one has been a scorcher. Media reports have been filled with coverage of heat wave after heat wave, with temperature records falling like dominoes.

But as they say, it’s not the heat, it’s the humidity, and that was painfully true in the first week of July as a slug of tropical air settled into the northeast United States. With dewpoints well into the 70s (25°C plus) and air temperatures pushing the century-mark (38°C), people suffered and systems from transportation to the electrical grid strained under the load. But as punishing as such soupy conditions are for people, there are other effects that are less well known but of critical importance to financial markets, where increased humidity can lead to billion-dollar losses for markets. Welcome to the weird world of high-frequency trading.

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Mouse Trap Game Used As An Actual Mouse Trap

Just when you thought you had explored all the weird stuff on YouTube, along comes [Shawn Woods] with his channel dedicated to testing different types of mouse traps. His weekly videos demonstrate the construction and ultimate effectiveness of everything from primitive traps that can be made in the field from sticks and rocks to 3D printed creations sent in from viewers. But his latest video might just be the weirdest one yet, as he found a way to use the classic “Mousetrap” board game to capture an actual rodent.

Well, sort of. For one, [Shawn] admits the “trap” is completely impractical and is just for fun. Which should be pretty obvious considering the thing is enclosed in a box the size of a small refrigerator. Second, the lucky rodent that gets to test drive this Milton Bradley-powered gadget is actually the family’s pet chinchilla which is obviously rather calm and we dare say accustomed to these sort of shenanigans.

The key to the whole contraption comes via two traditional mousetraps, one on either end of the game’s more fanciful rendition of the same device. The first trap is used to pull the crank which gets the board game going when the mouse steps on the pad (a piece of wood with padding prevents the bar from actually hitting the animal). The game goes through its nostalgic routine featuring metal balls rolling down tracks and figurines on jumping boards, eventually triggering the second real mouse trap. In this case, the trap pulls a rope which closes a door at the opening of the box.

Assuming your target rodent is very patient and not startled by the cacophony of plastic machinery, the whole thing works perfectly. To use the parlance of his channel, this is what’s known as a “Live Catch” trap as it doesn’t hurt the mouse and lets you easily remove them after the fact. Which is the least you could do after humiliating it like this.

While likely the most unique, it surely isn’t the only mouse trap we’ve ever covered here at Hackaday. This clever soda bottle trap can be built cheaply and easily, but if you want something expensive and complex you can always use a Raspberry Pi.

[Thanks to Pete for the tip.]

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Rolling Out A Slick Rotary Phase Converter

Home machinists can often find great deals on used industrial equipment, and many a South Bend lathe or Bridgeport milling machine has followed someone home. Then comes the moment to plug it in, and the new owner discovers that the three-phase plug needed to power the new beast is nowhere to be found in the shop. Thus commences the weeping and the gnashing of teeth.

Luckily, [Handmade Extreme] is ahead of the curve in terms of shop power, and built a rotary phase converter to power his machines. Industry generally runs on three-phase AC systems, mainly because three-phase electric motors are so much more efficient and compact than the equivalent single-phase motor. But residential electrical service is either split-phase or, in the UK where [Handmade Extreme] is based, single phase. A rotary phase converter is an electromechanical device that can generate the missing phases – in essence a three-phase motor that can run on one winding and generate the missing phases across the other windings. It needs some supporting control circuitry to do so, such as timers and contactors to switch the winding connections once the motor starts, plus capacitors for motor starting and for balancing the voltage across the phases. The control gear is DIN-rail mounted and neatly wired to a smart-looking control panel. Everything is housed in a sturdy enclosure that’s big enough to serve as a mobile tool cart. It’s a really nice job – watch the whole build in the video below.

If you’re interested in power distribution, we’ve got a primer that covers the basics. And if you’re in the market for machine tools, [Quinn]’s machine tool buyer’s guide will let you decide if a three-phase machine is worth the extra effort.

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