Boost Peak Power Tracking Battery Charger

May 5, 2014 by 25 Comments

[Rusdy] is building a solar charger for his electric bike, and quickly realized the lithium cells in his bike wouldn’t work well with the most common charge controllers out there. Solar cells have an IV curve, of course, and this changes with the amount of sunlight, requiring some conversion circuitry. Most of the charge controllers out there operate in buck mode, but the commercial boost mode converters [Rusdy] needed for his 36V battery are pricey as all get out. What was [Rusdy] to do? Build his own Boost MPPT solar charger, of course.

The circuit used for the charge circuit is fairly similar to a boost converter, with a little bit of logic required to get the maximum power out of the solar cells. [Rusdy] had an Arduino lying around, so that took care of the logic, and by sampling the voltage and current with the analog pins, he can turn a MOSFET on and off to get the most out of his solar cells.

The finished product works perfectly with an efficiency greater than 87%. Charging current and the final trickle charge is adjustable through software, allowing [Rusdy] to get the most out of his solar panels and electric bike. The board itself is just a prototype and could use a layout revision, but we’ve got to hand it to him for cloning a >$300 charge controller with an Arduino and a few scraps in a part drawer.

 

2014 Imagine RIT: An Innovation And Creativity Festival In Rochester, NY

May 5, 2014 by 14 Comments

Metal Imagine RIT Sign

Every year, the Rochester Institute of Technology hosts Imagine RIT, an innovation and creativity festival “that showcases the innovative and creative spirit of RIT students, faculty and staff.” The festival is free to the public and really brings the community together to celebrate technology, science, art, innovation, and creativity! We had the chance to attend this weekend and we had a blast looking at all of the engineering projects on display.

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Building A CO2 Laser In A Hardware Store

May 5, 2014 by 67 Comments

Over on the Projects site, [ThunderSqueak] is pushing the bounds of what anyone would call reasonable and is building a CO2 laser from parts that can be found in any home improvement store.

Despite being able to cut wood, paper, and a bunch of other everyday materials, a carbon dioxide laser is actually surprisingly simple. All you need to do is fill a tube with CO2, put some mirrors and lenses on each end, and run an electric current through the gas. In practice, though, there’s a lot of extra bits and bobs required for a working laser.

[ThunderSqueak] will need some sort of cooling for his laser, and for that he’s constructed a watercooling jacket out of 2″ PVC. In the end caps, a pair of brass pipe fittings are JB Welded in place, allowing a place for the mirror assembly and lenses.

The mirror mounts are the key component of this build, but the construction method is surprisingly simple. [ThunderSqueak] is using a few brass barbed hose fittings, with washers stuck on one end. The washers are drilled to accept a trio of bolts that will allow the mirrors to be perfectly parallel; anything less and the CO2 won’t lase.

The build isn’t complete yet, but having already built a few lasers, there’s little doubt [ThunderSqueak] will be able to pull this one off as well.

 

Bomb Clock Scares You Awake!

May 5, 2014 by 25 Comments

Bomb Clock Scares You Awake

What better way to wake up than by fearing your impending explosion if you don’t hit the correct snooze combination! This is the DEVESTATOR (Translated), [Jacek’s] latest fun project, straight from Poland.

As an avid paintball and airsoft fan, [Jacek] wanted to build a unique clock — so he decided to make his own classic dynamite stick bomb… clock. He’s using a ATmega8 microcontroller at the heart of the project with both a DS1307 RTC and a DS1820 temperature sensor, because just for kicks, the clock also monitors ambient temperature!

To add to the realism of the project he also designed the PCB from scratch using Eagle CAD, which allowed him to make  the whole thing look even more threatening. To actually make the PCB he used the laminate thermal transfer method. The four buttons on the PCB allow you to scroll through the date, time, temperature, and set alarm times.

Oh and the “dynamite”? Paper towel rolls covered in red tape.

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Huge RGB Ring Light Clock

May 5, 2014 by 16 Comments

After several months of work, [Greg] has completed one of the most polished LED clocks we’ve ever seen. It’s based on the WS2812 RGB LEDs, with an interesting PCB that allowed [Greg] to make a huge board without spending a lot of money.

The board is made of five interlocking segments, held together with the connections for power and data. Four of these boards contain only LEDs, but the fifth controller board is loaded up with an MSP430 microcontroller, a few capsense pads for a 1-D touch controller, and programming headers.

Finishing up the soldering, [Greg] had a beautiful LED ring light capable of being programmed as a clock, but no enclosure. A normal plastic case simply wouldn’t do, so [Greg] decided to try something he’d never done before: casting the PCB inside a block of resin.

A circular mold was made out of a piece of MDF and a router, and after some problems with clear resin that just wouldn’t cure, his ring light was embedded in a hard, transparent enclosure.  Conveniently stuck in the mold, of course. The MDF had absorbed a little bit of the resin, forcing [Greg] to mill the resin ring free from the wood, with a lot of finish sanding to make the clock pretty.

It’s a clock that demonstrates [Greg]’s copious manufacturing skills, and also his ability to troubleshoot the problems that arose. While he probably won’t be casting things inside an MDF mold anymore, with the right tools [Greg] could easily scale this up for some small-scale manufacturing.

 

TERMES: Termite Inspired Robots

May 4, 2014 by 10 Comments

termite inspired robots

Termites, if you think about it, are actually quite amazing. They are capable of building massive complex structures without direct leadership. The Wyss Institute at Harvard is attempting to create robots that can act in a similar way.

Typically if you have a robotic assembly line, if one robot goes down, the whole line shuts down. If it’s an assembly line of people, and one person calls in sick — they still manage, because people are adaptable. What the Wyss Institute is researching is  how to create robots that can work together, or by themselves, with one goal in mind — in this case, building a 3D structure.

In the following demonstration videos they show off their construction-bots assembling a building using basic building blocks. Each robot is completely independent — unaware of the other robots working the same task. It wouldn’t matter if you had one, or even 10 robots — the end result would be the same.

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Rechargeable Work Lamp Brightens Your Night

May 4, 2014 by 8 Comments

Portable power station has DC, AC and Light on board.

Most of us tinkerers will at some point find ourselves needing electrical power in a remote area. Cordless tools are an option, but what if you need more than that? [Garage Monkey San] set out to solve this problem by creating a portable power station that has on-board AC outlets, 12v and 5vdc outputs and an integrated spot light.

This project is housed in a plastic ammo case that’s large enough to contain all of the necessary parts and has a convenient carrying handle. The 12vdc sealed lead acid battery power source is kept topped off by a car battery float charger. Light is provided by an LED off road fog lamp mounted to the top of the case that has a small appetite for power, ensuring long battery life. An easy addition at this point was a 12v car accessory outlet which only adds to the versatility of the project.

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