DIY Portable Charger/generator

September 8, 2011 by Mike Nathan 26 Comments

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[Glenn] from The Back Shed has built a lot of windmills and stationary generators over the years, but recently decided to try his hand at building something a bit more portable.

The charger is based of a relatively simple design, employing a 5.2 HP Kubota 4 stroke motor and a 12v car alternator to provide power. While you might be inclined to point out that his charger does exactly what an alternator and motor are built to do, there was a bit more to it than simply slapping the two parts together.

A laser cut adapter plate holds the motor and alternator together, but once [Glenn] wrapped things up and gave the motor a spin, he realized that he was driving the alternator backwards. This would eventually cause the alternator to overheat since the cooling fan was running the wrong way. He removed the fan and reversed the fins with a hammer so that he could get the cooling he needed without having to reinstall the alternator in the opposite orientation.

The whole kit was mounted on a hand truck for portability, and [Glenn] says that the charger/generator only needs to run about 5 minutes before a dead battery has enough juice to crank an engine.

[via HackedGadgets]

Power Tool Battery Charger Repair

July 21, 2011 by Mike Nathan 14 Comments

drill_battery_charger_repair

[Webby] inherited a cordless drill from his dad and when he finally got around to using it, found that the charger was dead in the water. He disassembled it and narrowed the issue down to the charger’s primary transformer, but didn’t know where to go from there. A friend suggested that the coil’s thermal fuse might have blown, and upon further investigation, [Webby] discovered that his friend was right.

He removed the dead fuse and soldered in a piece of wire just for testing – not surprisingly the charger sprang to life. He picked up a new thermal fuse to replace the old one, but he wasn’t quite satisfied with the fix just yet. If the fuse burned out once already, there’s little to stop it from happening again, so he decided that installing a small cooling fan would be a good idea. He mounted the fan on the outside of the case after cutting some vent holes, leeching power from the charger itself.

While simply adding a fan to the charger might not be everyone’s idea of a perfect solution, it has worked out quite well for [Webby] in the past, so if it isn’t broken…

[via HackedGadgets]

Alternative Phone Charging Devices

June 30, 2011 by Jeremy Cook 32 Comments

We’ve all heard of solar cells that charge your devices, or the odd flashlight that charges when you shake it, but this style charger should be new to almost everyone. This “pan charger” is reportedly capable of charging a cell phone or other mobile device using a USB connection in 3 to 5 hours. It also has a built-in radio and lantern. This should be a great tool for surviving a zombie apocalypse or if you simply live in a region without readily available power.

A second charger, currently being used in Africa, is an adaptation of a small generator hooked up to a bicycle. As this form of transportation is quite common in developing nations, this simple idea definitely shows promise. Check out the video of the bike cell phone charger after the break. Continue reading “Alternative Phone Charging Devices” →

Portable Bench Supply Carries Around 10 Amp-hours Of Juice

March 29, 2011 by Mike Szczys 14 Comments

[Punish3r] wanted to have power for prototyping on the go. What he came up with is this little thing above. Inside you’ll find common components that let the unit provide 10 amp hours of current with a 12V 500mA output.

The storage capacity is provided by a dozen Lithium batteries. These 3.7V cheapies are wired in parallel behind a protection board. For charging and discharging, a Sparkfun LiPo charger board was used, taking care of all the work necessary to top off the batteries using a wall-wort. The final piece in the puzzle is a boost converter that provides the regulated 12v connected to the red and black banana plug receivers on the bottom of the case.

This is very much a plug-and-play design… just make sure you hook the parts up correctly and you’re up and running. We would love to see a roll-your-own boost converter circuit that include a switch or dial that lets you select common PSU voltage levels. If you’re going to the trouble to make your own board you might as well incorporate the charging circuit at the same time.

[Thanks Paul]

Cellphone Charger Has A USB Port Forced Upon It

March 16, 2011 by Mike Szczys 21 Comments

We still can’t figure out why a standard charging scheme hasn’t been developed for handheld devices (other than greed). Certainly we understand that many devices have different electrical needs as far as voltage and current are concerned, but we still long for the ability to use one charger for many different doodads. [Rupin] is trying to narrow down the number of dedicated chargers he uses by adding a USB charging port to his Nokia cellphone charger. Since the USB standard calls for regulated 5V a hack like this can often be done just by patching into the power output coming off of the voltage regulator in the plug housing of the device. [Rupin’s] charger had 5V printed on the case, but when he probed the output he found well over 8 volts. He added a 7805 linear regulator to get the stable output he needed, then cut a hole in the case to house the connector.

Since [Rupin] wants to use this as an iPod charger he couldn’t just let the two data lines float. Apple uses a specific charger verification scheme which requires some voltage dividers to get the device to start charging.

Toy Helicopter Charging Fix

February 20, 2011 by Mike Szczys 16 Comments

[Onefivefour] was surprised that his E-flite Blade MCX radio controlled helicopter came with a charger that used AA batteries to recharge the lithium batteries in the flying unit. Yeah, that’s a bit crazy. He set out to modify the base unit to work with AC power. There are four batteries inside this base unit, one of them powers the charge detector circuit and the others are used to juice-up the chopper’s rechargeable cells. He took a 5V regulated charger from a Motorola cellphone and modified it to interface with the contacts for the three AA cells. Like the Magic Trackpad hack, he did this without altering the holder by cutting a couple of pencils to length and attaching the positive and negative contacts from the AC charger to them. Check out the video after the break for a walk though, noting how he still has the option to go back to battery power if he so chooses.

Continue reading “Toy Helicopter Charging Fix” →

Breathing Motion Powered USB Charger

December 5, 2010 by Mike Szczys 32 Comments

When your batteries run low you can use your body to recharge them. This contraption generates power from chest expansion while breathing. [Jmengel] used some gears from old optical drives to boost the RPM generated by a belt around your torso that he calls a thorax expansion coupler. When you breath in, that belt pulls on a plate that spins the gears, ultimately rotating a small motor. The AC current generated by that motor is run through a rectifier and a boost converter, then fed to a charging circuit.

Does it work? Not really, as this only outputs around 50 mW. But we like the twinge of Dune nostalgia we get looking at it. Wouldn’t this be a perfect addition to a stillsuit?