Hackaday At MakeDC

makedc

Last Wednesday, our Hackaday travels took us to the Washington, DC area for a visit to NOVA Labs near Dulles and a yet-to-be opened Metro stop. Also on our itinerary was a visit to MakeDC, an informal get together for people around the nation’s capitol to show off their latest projects and builds.

The highlight of the evening was a pair of talks from [Julian] and [Taylor] on a project they did for work: a social cooler, or a locked box holding cool drinks that will only open when enough people send a text to a certain number. We’ve got [Julian]‘s talk on video, but despite our fancy new camera gear for this sorta thing, [Taylor]‘s demo of what an Electric Imp can do was lost to the digital wastes.

Aside from [Julian]‘s talk on APIs and [Taylor]‘s talk on the Electric Imp, there were a few impromptu presentations from the attendees. One of the most thorough was the duo from Shiny & Jackal Cosplay, crafters of EVA foam and LEDs. Truth be told, Hackaday doesn’t see many of these ‘softer’, cosplay and prop making builds in the tip line, and that’s a shame; the amount of skill that goes into these costumes is at least as equal as a woodsmith that can build fine furniture using only hand tools.

Perhaps a little premature, but TechShop is opening a new location in Arlington, VA at the end of the month. The GM [Addam Hall] was there scoping out the hacks and letting the attendees know there’s going to be a huge, awesome shop that’s down town in Crystal City. Close enough to public transportation, anyway, because anyone who drives in DC is certifiable.

The last item of note isn’t a build yet, but it’s shaping up to be pretty cool. It’s BRWRY – pronounced, ‘brewery’ – and will be a semi-automated beer making machine. Robots and beer, what can’t you love?

We’d like to thank [Zach], [Julian], [Taylor], and all the other guys from iStrategyLabs for putting together a nice evening of hanging out, drinking beer, eating pizza, and talking about what you’ve built. We had a great time, and we’re looking forward to the next one, as well as any other similar get together in other cities.

Searching For Makers In Washington DC

makeDC

Despite there being an inordinate amount of techies and tech companies in the Washington, DC/Northern Virginia area, there aren’t really that many hacker/makerspaces, or really anywhere else for tinkering, building, and generally futzing around with a soldering iron. [Zach] thought it was time for a change and is now organizing the second Make DC an informal get together to show off your latest projects and builds. Here’s the best part: Hackaday is coming, and we’re bringing some sweet swag.

Right now [Matt] has two talks lined up focused on bringing APIs into the physical world. There’s space for plenty more speakers, so if you have something to show off be sure to sign up.

The event is scheduled for Wednesday, March 19, 6:30 PM, half a block away from the Dupont Circle Metro station. Be there. You’ll get a sticker at least.

Experimenting with bridge rectifers for AC to DC power conversion

The folks over at Toymaker Television have put together another episode. This time they’re looking at bridge rectifiers and how they’re used in AC to DC converters.

This is a simple concept which is worth taking the time to study for those unfamiliar with it. Since Alternating Current is made up of cycles of positive and negative signals it must be converted before use in Direct Current circuits; a process called rectification. This is done using a series of 1-way gates (diodes) in a layout called a bridge rectifier. That’s the diamond shape seen in the diagram above.

This episode, which is embedded after the break, takes a good long look at the concept. One of the things we like best about the presentation is that the hosts of the show talk about actual electron flow. This is always a quagmire with those new to electronics, as schematics portray flow from positive to negative, but electron theory suggests that actual electron flow is the exact opposite. [Read more...]

Power supplies and transformers; a learning experience

[Ladyada] is working on a tutorial series covering power supplies. If you’ve ever built an electronic project you’ve used some type of power supply but we think that most people have no idea how you get from mains power to the DC voltages that most small projects use. So if you want to learn, get started with the first installment which covers AC/DC converters based on a transformer like the one seen above.

These transformers are inside the heavy and hot wall-wart plugs that come with many electronics. We used one along with a breadboard power supply when building the pumpkin LED matrix. They use a pair of coils to step down the voltage to a much smaller level. From there it’s a matter of rectifying the AC into DC power, which she talks about in an easy to follow discussion.

We understand this type of converter quite well but we’re a bit foggy on switch-mode AC/DC converters that don’t use a transformer. They’re much better because you don’t have to build a regulator into the target project like you do with wall-warts. Can’t wait until she gets to that part of the series!

Hacker Housing – Rally to Restore Sanity

HacDC, Washington DC’s own hackerspace has been kind enough to open their doors (and floors) to fellow hackers planning on visiting DC this weekend for the upcoming Rally to Restore Sanity. They are taking registrations now, and space is limited, so act fast. They have a suggested donation of $20 a night, which will get you floor space and breakfast each morning, as well as the warm feeling of supporting a community based Hackerspace. Details can be found on their registration page, and please make sure you read the rules before registering. Thanks again to HacDC for supporting the Hacker community!

In other news, Hack a Day will be at the Rally, so keep an eye out for the writers wearing the Hack a Day shirts, as well as the HackaDay Twitter. If you get seen with one of us, you might just make it to the fan gallery. We will also be handing out some HackaDay Swag if you catch us soon enough on Saturday.

Dead motor? Think again

While hobby brush motors are pretty cheap now adays, there’s always that feeling of why replace when you can rebuild and reuse. As such [John Carr] presents how to change the brush position in motors to revive a dead motor. So long as the motor dies from natural causes commutator wear, the idea is the brushes can be moved along the axes and fixed to a new portion of commutator that’s not worn at all. [John] also goes through the details of some tricky reassembly, but we think to make this complete a guide on brush replacement and commutator replacement might be in order hint hint.

Adjustable breadboard supply

breadboardpowersupply

adafruit industries’ latest product is an adjustable breadboard power supply kit. We’ve seen breadboard supplies before, but like most of adafruit’s kits, this is the best design you’re going to encounter. It uses an MIC2941 voltage regulator instead of the more commonplace LM317. It has a very low dropout which means your output voltage can be much closer to the input voltage. Their example is using 3AAA or a Li-Ion battery for an output of 3.3V. Input can be through a barrel jack or terminal blocks. There is a selection switch for 3.3, 5, and adjustable voltage. Using the adjustment pot you can select an output voltage anywhere from 1.3V to within .5V of the 20V maximum input. The adjusted output voltage will remain the same even if you increase the input voltage. Like all of their kits, you can find schematics, assembly and usage instructions, on their project site.

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