Comments for alex hessler

Comment on Solar Powered Lantern by Bill

Bill — Fri, 02 Dec 2011 01:43:44 +0000

Alex, I am using a solar panel from a yard light, it puts out about 5 volts. Thanks again for your help. Bill

Comment on Solar Powered Lantern by Alex

Alex — Fri, 02 Dec 2011 01:28:14 +0000

I had exactly this problem when I was using flexible (amorphous) solar panels instead of crystalline panels. Are you using amorphous panels? They have great performance, but don’t let any current flow through them when they’re not lit. The PNP transistor needs a small amount of current going to its base for it to open. This current is provided by the battery, through the solar panel, when the voltage on the panel is low. Amorphous cells don’t appear to allow this current flow. At least that was my diagnosis at the time. I’m sure an electrical engineer could give a more accurate analysis.

Comment on Solar Powered Lantern by Bill

Bill — Thu, 01 Dec 2011 22:58:17 +0000

I finally got the circuit working, however I still have a problem. When I touch the led leads to the double a battery leads it is nice and bright, but when the circuit turns on the light it is very dim, could it be the resistor is too big? I get the same voltage at the led leads that I get at the batteries but a dim led output. Any ides’s. Thanks Bill

Comment on Solar Powered Lantern by Alex

Alex — Sat, 26 Nov 2011 20:18:47 +0000

In this design, the led should turn on when no light is on the solar panel. It sounds like your lantern is doing the opposite, so the led turns on when the solar panel is lit. Is that the behavior you’re seeing? If so it’s possible that you’re using a NPN instead of a PNP transistor. I’ve also found that the type of solar panel makes a difference. For example, the thin flexible solar panels do not work with this design because they do not allow any current to pass through them then they’re not lit.

Comment on Solar Powered Lantern by Bill

Bill — Sat, 26 Nov 2011 15:54:28 +0000

I built a solar powered lamp out of an old kerosene lamp, I use two aa rechargeable batts and a yellow flicker led. My problem is the light works fine all day long, when ever I put something over the solar cell the light works fine, however at night the light does not come on. When I shine a light on the panel the light comes on and stays on all night. I have tried a lot of fixes but nothing works, any idea’s. Thanks Bill

Comment on Solar Powered Lantern by rkrao

rkrao — Fri, 18 Nov 2011 12:24:39 +0000

very nice instructions to make a solar lamp;thanks for giving the parts list;i wish to try making one.

Comment on Solar Powered Lantern by Brian

Brian — Wed, 19 Oct 2011 00:40:08 +0000

Wow, very well done. I’m inspired to try the same thing….

Comment on Solar Powered Lantern by Sgtnobleusa

Sgtnobleusa — Sat, 27 Aug 2011 18:45:12 +0000

Very nice instructional. I thought the tape around the led lights is a great idea to simulate a lit wick. Thanks

Comment on Solar Powered Lantern by anon

anon — Fri, 26 Aug 2011 02:50:41 +0000

Very nice. Thanks.

Comment on Mater Private Eye by vaishali

vaishali — Sun, 12 Jun 2011 17:58:09 +0000

hey alex ur work is just superb…….its ma dream to be in pixar n m working for dat.