Comments on: DIY Solar Lamp

By: Along

Along — Fri, 30 Aug 2013 10:11:08 +0000

just wondering, How to calculate the resistor size, if we only use 1 3.7v LED light in the case above? is it 2 ohm? But will the LED can take 500ma?

By: admin

admin — Mon, 24 Sep 2012 12:49:32 +0000

In reply to Clark.

Hi Clark,

We have a USB Out cable that just has positive and negative wires, it stretches to about 2-3 feet. See: https://www.voltaicsystems.com/adapters.shtml#cables

Thanks,
Jeff

By: Clark

Clark — Sat, 22 Sep 2012 21:01:20 +0000

I wanted to use a USB cord from an old USB mouse to rewire a study lamp and then connect 3 LEDs as instructedd above. Wondering if the wires will be able to carry enough current. I will not need the green and white wires and the stranded shielding. Not sure how to prevent short of the green/white/shielding. If I connect my lamp to a USB from a laptop pc, want to make sure I dont blow out the PC. Do you have a USB cord that I could use that only has the +5v and ground wires connected? I need about a 2 1/2 to 3 foot long cable.

By: Clark Pontius

Clark Pontius — Mon, 20 Feb 2012 20:28:13 +0000

Thanks for this type project. Although it may be easier to purchase some ready made stuff, it is imperative that people get back in touch with “tinkering” and this is just the type of project to start with. As for me, I will still have to scrape together enough money for the parts. But now I have instructions! Thanks!

By: Chad Armstrong

Chad Armstrong — Sun, 01 Jan 2012 03:41:24 +0000

An interesting project. I love this little demonstrations on this blog.

However, I found it easier (and likely cheaper for me) to purchase a USB-powered LED light and then plug it into a USB battery pack like the V11 or the iGo Charge Anywhere.