Day: July 21, 2017

Hackaday Eclipse Meetups

July 21, 2017 by 46 Comments

Hackaday is all over this eclipse. There are thousands of members of the Hackaday community headed to a narrow swath of the United States on August 21st to revel in an incredibly rare, scientifically predictable life experience: a total eclipse of the sun.

Do not do it in solitude, get together and celebrate! Check out the Hackaday Eclipse Meetups page which shows where meetups are happening. And adding your own is simple. It’s a great day to meet up with other Hackaday readers and celebrate the day that the moon passed perfectly between you and the sun.

You can’t just stare directly at the sun, you need some eclipse glasses. We’re printing up some in black, adorned with the Jolly Wrencher and sending them out to all organized meetups, so get your event page up today and you’re on the list for a little bit of sweet swag. Look for the button on the Eclipse page that says “Host a meetup”.

I’m Too Cool to Watch an Eclipse

If you don’t get what all the hubbub is, you’re missing out. A total eclipse of the sun is an amazing life experience in so many ways. First off, they’re incredibly rare. There hasn’t been a total eclipse visible in the continental United States since 1979. The majority of the North American readership hasn’t even had the chance to see one in their lifetimes.

This eclipse shadow visualization is incredible. See the entire transit and learn how they produced this from available data

But of course it goes beyond the value of mere scarcity. Being able to understand, and predict an eclipse conveys a great deal about the progress of humanity. For millennia, a solar eclipse was a shocking (perhaps horrifying) experience. But through the scientific process of observation, the advances of record keeping, and the work of untold numbers of early astronomers we learned. Solar and Lunar eclipses were events that challenged thinking and became some of the earliest scientific discoveries.

This type of advancement hasn’t stopped. Even this year the application of the newest technology is present. Just one example that will turn your head is the shadow simulation that we saw in January. The moon isn’t a perfect sphere, and the combination of its landscape and that of the Earth means the outer fringes of totality will not be straight lines, but an undulating path. It’s a small detail realized in a profound way by a citizen scientist so that we may all enjoy it. Isn’t being alive now absolutely stunning?

Boil it Down for Me

So no, watching a rock cast a shadow won’t blow your mind. But understanding that the movement of this shadow isn’t random, that we didn’t always understand it, and that there are huge forces at work here will humble your modern brain and leave you awestruck. It’s a rare chance to observe with your own senses the evidence of huge masses governed by gigantic gravitational forces at incomprehensible distances through the simple act of a shadow racing across the landscape.

Be there, and make it a celebration of science, humanity, and your own life experience. Share your eclipse meetup now!

Serious DX: The Deep Space Network

July 21, 2017 by 28 Comments

Humanity has been a spacefaring species for barely sixty years now. In that brief time, we’ve fairly mastered the business of putting objects into orbit around the Earth, and done so with such gusto that a cloud of both useful and useless objects now surrounds us. Communicating with satellites in Earth orbit is almost trivial; your phone is probably listening to at least half a dozen geosynchronous GPS birds right now, and any ham radio operator can chat with the astronauts aboard the ISS with nothing more that a $30 handy-talkie and a homemade antenna.

But once our spacecraft get much beyond geosynchronous orbit, communications get a little dicier. The inverse square law and the limited power budget available to most interplanetary craft exact a toll on how much RF energy can be sent back home. And yet the science of these missions demands a reliable connection with enough bandwidth to both control the spacecraft and to retrieve its precious cargo of data. That requires a powerful radio network with some mighty big ears, but as we’ll see, NASA isn’t the only one listening to what’s happening out in deep space. Continue reading “Serious DX: The Deep Space Network” →

Push Button, Receive Beverage!

July 21, 2017 by 9 Comments

Here’s a rec-room ready hack: an automatic drink dispenser.

[truebassB]’s dispenser operates around a 555 timer, adjusted by a potentiometer. Push a button and a cup pours in a few seconds, or hold the other button to dispense as much as you want.

The dispenser is made from MDF and particle board glued together, with some LEDs and paper prints to spruce it up. Just don’t forget a small spill sink for any miscalculated pours. You needn’t fret over the internals either, as the parts are easily acquired: a pair of momentary switches, a 12V micro air pump, a brass nozzle, food-safe pvc tube,  a custom 555 timing circuit — otherwise readily available online — a toggle switch, a power supply plug plus adapter and a 12V battery.

Continue reading “Push Button, Receive Beverage!” →

DC Motor Whirligig Generates Power

July 21, 2017 by 25 Comments

Everyone knows that if you spin the shaft of a DC motor, it will generate power. [Vapsvus] has found a novel way to do this with no direct mechanical connection to the shaft. He simply taped a loop of string around to the motor can. This effectively turns the motor into a whirligig. Flip the motor to give the string a few twists, then pull on the two loops. The string unwinds and then winds back up, just like the toy we all grew up with.

The interesting thing is that the motor generates usable power when being spun like this. [Vapsvus] connected two LEDs to the motor’s leads to show what’s happening. The white LED glows when current travels from positive to negative, and the red LED glows when current travels from negative to positive.

What’s going on under the hood is all about momentum. As the motor can starts to spin, the heavy iron rotor remains still. Power is generated. Eventually, friction and torque from back EMF cause the rotor to spin as well. By the time the rotor is spinning, the motor can is already reversing direction.This generates even more power with current traveling in reverse.

Sure, this isn’t exactly practical, but we’d love to see how far it could be taken. Add a super capacitor, and we bet it would be more efficient than the magnetic shake lights which were popular a few years back.

Whirligigs are usefully little devices. Not only do they keep children entertained, you can use them as centrifuges.

Continue reading “DC Motor Whirligig Generates Power” →