Homemade Lightwedge Project

[slayda]

You might want to use some watch (button) batteries instead of the AAA's. Smaller size & less weight & should be plenty adequate for LEDs.

[Bob Russell]

Originally Posted by Vaporware

Yes, it was my inspiration to get off my butt. I have pictures of the final design, but my card reader isn't working properly and I can't get them right now.

Hey, maybe if you get the thing all worked out, it will be LightWedge's inspiration to get off their bu++s and make one also!

[NatCh]

Maybe Vaporware can forward a functioning prototype to them with a note that says something like: "C'mon, LightWedge, it ain't rocket science!"

[scotty1024]

Originally Posted by Vaporware

I think obelix is correct in abandoning the 4AAA batteries and working with a mobile phone battery.

Have you checked the Reader's USB and/or dock ports to see if you can source power from either of them?

[Vaporware]

Nah, I'm pretty sure you can't tap the battery from the reader, besides it would be the equivalent of hooking up a big screen TV to a scooter for power. a 3.7v 900mAHr battery like I'm planning on using for the lights is probably bigger than the reader's battery!

My next design will be much more like obelix's light and less like a hacked lightwedge.

[NatCh]

The USB port doesn't give power -- Sony said so, and I've checked it myself.

The SD/MMC card port might, I haven't tried it. In any case, I tend to agree with Vaporware about the moped/plasma TV thing. Nice visual that.

[yvanleterrible]

How about the power port itself?

[NatCh]

Heh, I haven't tried the power port, but those things are usually one-way. I can't check it right now 'cause my DMM is at home, and I'm not.

[TheMadBrewer]

Originally Posted by slayda

You might want to use some watch (button) batteries instead of the AAA's. Smaller size & less weight & should be plenty adequate for LEDs.

I'd vote for AAA's -- I want to use rechargables. When I travel I always carry a fairly small dual voltage charger. I don't want to have to worry about what they call this and that watch battery in foreign country

Actually, if the power pack is separate, one could have options for both.

[scotty1024]

Originally Posted by NatCh

I tend to agree with Vaporware about the moped/plasma TV thing. Nice visual that.

Actually his visual is incorrect. These light designs have at most 2 LEDs, you can run two in series so the current draw is roughly 20ma. 900/20 = 45 hours.

Not exactly a "plasma screen" load on the Reader's battery.

Power sourced from the Reader would be regulated so all you need are 2 LED's, a drop resister to set the ma's and a connector to provide a nice stable light source.

[yvanleterrible]

Scotty! Could we get power from the reader's power port?

[Vaporware]

Originally Posted by scotty1024

Actually his visual is incorrect. These light designs have at most 2 LEDs, you can run two in series so the current draw is roughly 20ma. 900/20 = 45 hours.

Not exactly a "plasma screen" load on the Reader's battery.

Power sourced from the Reader would be regulated so all you need are 2 LED's, a drop resister to set the ma's and a connector to provide a nice stable light source.

I think a consistant 20 mA draw would be a serious battery drain on something that only draws on page refreshes, but then again it's probably less draw than the music player.

Originally Posted by yvanleterrible

Scotty! Could we get power from the reader's power port?

I've been out of town all weekend, so I'll check after work.

[scotty1024]

Originally Posted by Vaporware

I think a consistant 20 mA draw would be a serious battery drain on something that only draws on page refreshes, but then again it's probably less draw than the music player.

It'll only draw 20ma when it is turned on. And from the looks of the pictures posted 20ma might be a teensy bit too much juice.

Originally Posted by yvanleterrible

Scotty! Could we get power from the reader's power port?

If I were a Sony hardware designer I would have made a play to management to make power available on the dock port so we could introduce a thumb board at some point.

The power port should have a low forward voltage diode to protect the device from reverse polarization of the power cable. The diode would have the side effect of preventing power being tapped from the device via that port.

[Vaporware]

Obelix, how the heck did you solder that FAN5607? If you could, could you explain your circuit? I am interested in reproducing your design.

[obelix]

Originally Posted by Vaporware

Obelix, how the heck did you solder that FAN5607? If you could, could you explain your circuit? I am interested in reproducing your design.

1. Glue the chip legs-up to the small piece of the circuit board.
2. With regular soldering iron (RadioShack $10) solder thin wires (extracted from multiple-strand wire) to the legs (be careful, do not touch them for more than 1 sec).
3. Put pieces of plastic tubing on the wires to isolate them.
4. Solder the opposite ends of the wires to capacitors and resistors soldered to the board at the earlier step.

Hint: You can get capacitors (of the type needed for the circuit) from any broken computer electronics. I got mine from damaged hard drive. Just take the biggest capacitors located at the power connector (box-shape, brown color). I did not care much about capaciance, I built 2 units and they both work fine, I think capacitance is not that important.

Sorry, I dont know exact English terms for many things like that, so if you will need more information, please drop me a message to m_ryb AT netzero DOT. com, if needed I can do more pictures.