Can i get a 3v that can light a led w... Science Toys | Science Blog | Log Out | Topics | Search
My Toys | Energy | Moderators | Register | Edit Profile

Scitoys Message Board » I am having trouble building one of the toys » Can i get a 3v that can light a led without any battery ? « Previous Next »

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

moustafa ibrahim moustafa (Mosnfady)
New member
Username: Mosnfady

Post Number: 1
Registered: 5-2007
Posted on Saturday, May 12, 2007 - 5:05 am:   Edit PostDelete PostView Post/Check IPPrint Post   Move Post (Moderator/Admin Only)Ban Poster IP (Moderator/Admin only)

hello every body,
i have read the chapter of Building a simple crystal radio)...i want to use thise circuit ( not as a radio receiver) but to obtain a suitable voltage that can light ( for led nearly 3 volt ) without any battary..... can i do that... are there any element must be added....( is it has a suitable amper).
or can i obtain thise voltage from any other source like water (from a sea or ...)
thanks,
Top of pagePrevious messageNext messageBottom of page Link to this message

Simon Quellen Field (Sfield)
Senior Member
Username: Sfield

Post Number: 1699
Registered: 12-2004
Posted on Sunday, May 13, 2007 - 6:57 pm:   Edit PostDelete PostView Post/Check IPPrint Post   Move Post (Moderator/Admin Only)Ban Poster IP (Moderator/Admin only)

High efficiency LEDs can emit light from very small currents.
Red LEDs don't need much in the way of voltage (as the color
moves more to the blue end of the specturm, the voltage required
goes up).

With a sufficiently long antenna and a good ground, you can get
a red LED to light up brightly.

photo of LED lit by crystal radio
Top of pagePrevious messageNext messageBottom of page Link to this message

moustafa ibrahim moustafa (Mosnfady)
New member
Username: Mosnfady

Post Number: 2
Registered: 5-2007
Posted on Monday, May 14, 2007 - 3:10 am:   Edit PostDelete PostView Post/Check IPPrint Post   Move Post (Moderator/Admin Only)Ban Poster IP (Moderator/Admin only)

thanks, simon for answer,
but how can i improve or amplify the current to make a good light- and what about the specifications of the antenna - are u have any document in this subject (lighting with no battery )
thanks again simon
Top of pagePrevious messageNext messageBottom of page Link to this message

Marcus Shaw (Schorhr)
Intermediate Member
Username: Schorhr

Post Number: 40
Registered: 9-2006
Posted on Saturday, May 26, 2007 - 6:21 pm:   Edit PostDelete PostView Post/Check IPPrint Post   Move Post (Moderator/Admin Only)Ban Poster IP (Moderator/Admin only)

Here are some circuits I found that make a led blink using no battery- one uses radiowaves (but also no details on antenna) and one uses the LED itself:
LEDs are not as good as solar cells, but will convert light into electricity.
LED drives itself from Mikrocontroller.net BBS
http://www.mikrocontroller.net/attachment/13446/kmcmled.gif

http://forum.electronicwerkstatt.de/phpBB/uploads/05564_1105033014_Image3smaller_file.jpg

(Probably wont load due to hotlinking block, go to the
german electroniwerkstatt-Forum and look at end of toppicpage, or click the other link after loading the forums page.
http://forum.electronicwerkstatt.de/phpBB/viewtopic.php?topic=28199&forum=34&start=0&pid2=146541&zeige=#id146541
Top of pagePrevious messageNext messageBottom of page Link to this message

scott (Ichyc)
Senior Member
Username: Ichyc

Post Number: 163
Registered: 6-2006
Posted on Monday, June 25, 2007 - 5:56 pm:   Edit PostDelete PostView Post/Check IPPrint Post   Move Post (Moderator/Admin Only)Ban Poster IP (Moderator/Admin only)

is there a way to make a cristal radio thatwill receve many channels at once basicly every one in range not to listen to, because it would not sound to good lol, but to receve as much power from electromagnetic radiation as possible?
Top of pagePrevious messageNext messageBottom of page Link to this message

Simon Quellen Field (Sfield)
Senior Member
Username: Sfield

Post Number: 1725
Registered: 12-2004
Posted on Thursday, July 12, 2007 - 2:30 pm:   Edit PostDelete PostView Post/Check IPPrint Post   Move Post (Moderator/Admin Only)Ban Poster IP (Moderator/Admin only)

Sure.
Just eliminate the tuning circuit.
Top of pagePrevious messageNext messageBottom of page Link to this message

moustafa ibrahim moustafa (Mosnfady)
New member
Username: Mosnfady

Post Number: 3
Registered: 5-2007
Posted on Wednesday, November 21, 2007 - 9:34 am:   Edit PostDelete PostView Post/Check IPPrint Post   Move Post (Moderator/Admin Only)Ban Poster IP (Moderator/Admin only)

ok, how can i increase the power of thise circuit

Add Your Message Here
Post:
Username: Posting Information:
This is a private posting area. Only registered users and moderators may post messages here.
Password:
Options: Enable HTML code in message
Automatically activate URLs in message
Action:
For those who have trouble spelling, the Google Toolbar (included in the Google Pack) can check and correct the spelling in your posts on this message board and others.

Renewable Energy

Topics | Last Day | Last Week | Tree View | Search | Help/Instructions | Program Credits Administration