Repurposing Server PSU For Your Charging Needs

July 17, 2012 by Mike Szczys 21 Comments

That grey box at the top of the photo is a modular power supply unit for a rack-mounted server system. [Sebastian] decided to repurpose it as a charging source for his RC batteries. He chose this HP DPS-600PB because of its power rating, efficiency, and you can get them at a reasonable price.

This is an active power factor corrected (APFC) PSU, which he says draws 40% less current than the non-APFC variety. Since he sometimes charges batteries in the field from a generator this is a big plus. But a bit of modification is necessary before it can be used as a source.

Since this is a rack device it has a set of connectors on the back. For power there are spade connectors which mate with a fin on the rack. He soldered positive and negative leads between the spades to interface with the battery chargers. The PSU won’t fire up if it’s not in the rack, so some jumper wires also need to be added connecting three of the interface pins.

With his modding all worked out he went on to use two PSUs for a 24V source, housing them to a nice carrying case while at it.

BattMan II: The Charger Your Batteries Deserve

June 17, 2012 by Caleb Kraft 13 Comments

When your radio controlled device batteries are drained, you’ve got no better option than to call on BattMan II. This device is packed full of features for cycling and charging various types of batteries. It is computer controlled via your parallel port (yeah, remember those?) and has companion software that allows you all kinds of control and data.

The writeup is rather extensive and includes schematics so you could build your own. There’s also a step by step breakdown of how each section functions as well as an explanation of each different charging method. Great work [Stefan]

if you just want a peak at the lengthy feature list, keep reading.

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Nook Touch Becomes A Desktop Computer

June 14, 2012 by Mike Szczys 6 Comments

It looks like [Renate] has been pounding out hack after hack on her Nook touch. It stands on its own now thanks to a tripod bracket hack which is the most recent work she’s done. But there are bunch of other modifications, all of which are linked after the break.

We believe that this is meant for displaying lyrics as she sings and plays along. To that end there’s a foot pedal attachment that lets her control the device. It connects to the Nook via a USB hub that allows her to interface multiple devices at once. This in itself is also a hack, as host mode isn’t an out-of-the-box feature for the device. In order to avoid having to disconnect everything in order to top off the battery, she also manged to get the thing to charge from the USB hub. In fact, with all this in one package she’s basically got herself a desktop computer.

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Automatic Capacitor Charger Lets You Have Fun With Sparks

May 22, 2012 by Mike Szczys 14 Comments

[GranTotem] is delighted by the sparks put out when a capacitor is rapidly discharged. But he’s not impressed at the relatively slow process of connecting them to a power supply for a recharge. So he built this auto-charging station for his capacitors that provides a shockingly good time almost continuously. Check out the video to see what we mean.

We always like to see the guts of the project, and that’s why we chose this image for the feature. But when everything is properly seated in the project box [GranTotem] has managed to achieve a really clean look. There are two barrel jack connectors on the end, one for 16V and the other for 20V inputs. The lid of the enclosure hosts an on/off switch, adjustment knob, and two banana connector terminals. Once switched on, a relay connects and disconnects the capacitor from the power supply at regular intervals which are adjusted by the knob. Just connect a couple of probes to those banana terminals and let the sparks reign down.

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Geeks Living Off The Grid Are Hard On Batteries

May 19, 2012 by Caleb Kraft 37 Comments

Many of you will remember [Mikey Sklar] from the multitude of times he’s been on hackaday. What you may not have noticed is that he is an ubergeek, living off the grid.

He has Solar PV battery bank, three electric vehicles, a shipping container loaded with battery powered tools and a small army of iRobot Roomba’s for cleaning. Getting the maximum lifetime out of a battery by removing sulfation is essential to keep expenses down.

Keeping expenses down is nearly a full time job when trying to live the homestead lifestyle. Our current culture makes it extremely difficult to survive completely on self made/grown things and bartering. They seem to be doing pretty well though. One way he can reduce his costs while still getting to enjoy some modern gadgets is to get longer life out of his batteries. He does this by using a capacitive battery charger and desolfator that he designed and affectionately calls “Da Pimp”. He also brings in a little bit of income by selling kits!

A capacitive charger behaves like a constant current power supply dynamically adjusting the voltage to get over the batteries internal resistance. Plus there is a pulse from the AC/DC conversion. This allows for old batteries to last longer and for dumpster dived to be used as replacements. Capacitive chargers are small, silent and super efficent (up to 60% more so than cheap transformer based chargers).

Of course, [Mikey] is a supporter of sharing information so you can also go to his site and download the schematics,bill of materials, gerber files, and files for the housing, to build one yourself.

Scavenging From Consumer Electronics To Make A Flame-powered Phone Charger

May 18, 2012 by Mike Szczys 32 Comments

[Gigafide] just finished building this flame-powered phone charger. The concept is not new. He grabbed a Peltier cooler and used the temperature differential between a flame and a heat sink to produce electricity used by the charger. If you search around here enough you’ll find plenty of candle-powered devices, and a few hacks that use a Peltier device in a bit more interesting way. But we really like his high-production value video, straightforward explanation of the concepts, and ability to source the components in consumer devices. We don’t think you’ll be disappointed by his video found after the break.

The Peltier device comes out of a USB drink chiller. It is supported by a metal stand made from electrical box covers and threaded rod. Underneath he’s using a gel fuel can used by the food industry, and above he’s got CPU heat sink and fan. This setup puts out around 1.5V but he’ll need a boost converter to charge a phone with that. A single AA battery charger meant to power your phone in a pinch is perfect for this application.

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Prototyping A Solar Charger For Your Truck

May 16, 2012 by Mike Szczys 13 Comments

[Bryan] got his hands on a solar panel and decided to take it on the road rather than throwing it on the roof of the house. On sunny days it will top off the car battery, letting him use his stereo in the middle of nowhere without needing to keep the engine running. Instead of buying a ready-made solution he chose to design and build his own charging circuitry.

The charger uses an Arduino, which draws its own power from the panel via a regulator. It senses the voltage level of the battery and the available juice from the panel, connecting or disconnecting it from the electrical system as necessary. The system includes a set of LED indicators, which he installed in the dashboard near the cigarette lighter. This also gave him an excuse to install a voltmeter which uses a 2.5 digit seven segment display to read out the battery voltage. You can see a brief overview after the break.

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