"Off Grid" DC Solar Electric Garage Lighting... Hard Wired and Fully Integrated

Instructables was kind enough to send me this neat little solar kit as a prize for being runner up in last year's "Off the Grid Contest".

The kit comes with a solar panel, an intelligent battery pack, a universal USB cell phone battery charger,  a wall adapter charger and a 12 volt LED light bulb with power cord.

The battery pack can be charged from either the solar panel or the wall charger from a set of terminals in the back. It has a built in charge controller as well as an alarm that will notify you of an error. On the front of the unit are two 12 volt "cigarette lighter" outlets and two 5 volt USB ports that you can use to draw power. On the front there is also a battery level indicator as well as a charge status indicator.

In these photos you can see the solar panel on a little wooden frame that I built for it. When I first got it I planned on using it for camping trips and emergencies so I made up this portable stand. Now I will make up an aluminum mount and mount it on the roof of my garage with the power cable routed through the roof deck, attic and over to the battery pack. For now I put the panel on the ground beside the shed whenever it's sunny.

The light bulb that came with the kit was particularly interesting. Even though its a 12VDC bulb it has an E26 screw base similar to the ones found on your conventional household 120VAC bulbs. The cord that was included had a bulb screw socket on one end and a "cigarette lighter" style plug on the other end to plug into the battery pack. As strange as the light bulb was it meant that I could install it in a conventional household light fixture as long as it was wired up for 12VDC and not 120VAC. I found more of the same bulbs on eBay and then gathered up some electrical boxes, 18/2 Romex wire, tools and got going.      

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how to transform your old electric oven into a modern digital thermostat controlled one (aka: the meringues solution!)

If you ever tried to cook meringues you knot that it's almost impossible if your oven can't keep a constant temperature over the time. Modern electric ovens have a digital integrated thermostat so to achieve that goal with no efforts, but if you like meringues and you have an old oven you could probably feel in troubles.. old thermostats only have a graduated scale, and the only way to maintain the exact temperature is to put a thermometer into the oven, then set the knob consequentially.
A better solution is to buy a digital temperature controller with a thermocouple, and connect it so it will regulate the oven in place of you. You need few tools for this project.
To avoid to cut the power cable of the oven you need to use a female socket, and connect it to the thermo controller with some wires. So you need a pair of screwdrivers and a wire stripper.

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330 volt "Shocking" Electric Deck of Cards! - (Electric Shock Kissing Prank)

Sorry, I could not read the content fromt this page.

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Electric Wurlitzharmonica

This week I attended Music Hack Day at the Drexel Excite Center.  There were many incredible projects there to investigate, as well as some seriously funky live music and some cool folks, all coming together for a 24-hour musical hackathon. The creative atmosphere was pretty inspiring, and out of this was born a weird new hybrid musical instrument -- the Electric Wurlitzharmonica, or the Wur-monica, for short.

With the Wur-monica, I have found a novel way to amplify a harmonica.  The Wur-monica does not have a microphone or pickup of any kind inside. Instead, the Wur-monica relies on the electromagnetic properties of the instrument itself as a signal source. In fact, the Wur-monica is based on the same elegant principle as my beloved Wurlitzer 200A electric piano (hence the name). 

How it works:
The original Wurlitzer Electric Pianos of the 1960s were gorgeous machines with a really interesting way of generating sound: instead of strings, the piano had large reeds struck by hammers (see picture). The reeds produced a signal using an ingenious electrostatic principle: the reeds were charged up to hundreds of volts, so that they formed a capacitor with the adjacent ground plate.  When the reeds vibrated, this capacitance changed, pushing electrons back and forth to magically produce ethereal honks, buzzes, crunches, and chimes. If you think about it, a condenser microphone also works in much the same way (except with parallel plates instead of vibrating reeds).  In a sense, each Wurlitzer piano reed is its own condenser microphone.

The Wur-monica works using the same principle as the Wurlitzer piano. Each brass reed inside the Wur-monica is mounted on a brass plate, but does not touch it.  This creates a very small capacitance between the reeds and the plate.  When a reed vibrates, this capacitance changes, creating a signal that can be amplified.  Again, no mics, pickups, or piezos are needed -- wires are connected directly to the reeds, so that the reeds themselves produce their own electrical signal.

The main advantage of this technique is that it should be immune to acoustic feedback, like a microphone would get.  But I'm also hoping to maybe capture a little of that crunchy, magical, soulful Wurlitzer sound in a pocket-sized instrument.

This project is only a proof of concept, so I didn't spend much time refining the circuitry, the method for mounting the reeds, or the intonation, for that matter. In fact, I only bothered to mount seven of the reeds, and one of them is still kind of wonky and shorts out the circuit if I blow too hard (you can hear it shorting in the video). Still, after only a few hours of hacking, I was pretty pleased with how the prototype looks and sounds. 

Please check it out and leave me some feedback!  And if you like classic devices updated with new electronics, check out my USB Typewriter instructable, too. And please vote for this project in the Pocket Sized Contest!  Thanks!

First Test:

Final Test (just before getting dizzy and passing out):

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