Post by thread:IR LED

part 0 1832 bytes <META content=text/html;charset=gb2312 http-equiv=Content-Type> <META content='"MSHTML 4.72.3110.7"' name=GENERATOR> </HEAD> <BODY bgColor=#ffffff> <DIV><FONT color=#000000><FONT face="Book Antiqua">Hi there,</FONT></FONT><FONT face="Book Antiqua"></FONT></DIV> <DIV><FONT color=#000000><FONT face="Book Antiqua"></FONT></FONT><FONT face="Book Antiqua"></FONT> </DIV> <DIV><FONT color=#000000><FONT face="Book Antiqua">  Is there a kind of IR LED can also emit visible light like LED ?</FONT></FONT><FONT face="Book Antiqua"></FONT></DIV> <DIV><FONT color=#000000><FONT face="Book Antiqua">  How do I know that it's working or not after assembly to a PCB board  without measuring the polarity ? </FONT></FONT><FONT face="Book Antiqua"></FONT></DIV> <DIV><FONT color=#000000><FONT face="Book Antiqua"></FONT></FONT><FONT face="Book Antiqua"></FONT> </DIV> <DIV><FONT color=#000000><FONT face="Book Antiqua">Best Rgds,</FONT></FONT><FONT face="Book Antiqua"></FONT></DIV> <DIV><FONT color=#000000><FONT face="Book Antiqua"></FONT></FONT><FONT face="Book Antiqua"></FONT> </DIV> <DIV><FONT color=#000000><FONT face="Book Antiqua">Willie W. HO</FONT></FONT></DIV></BODY></HTML> </x-html>

WILLIE W. HO wrote: > > Hi there, > > Is there a kind of IR LED can also emit visible light like LED ? > How do I know that it's working or not after assembly to a PCB board withou t measuring the polarity ? {Quote hidden}> > Best Rgds, > > Willie W. HO > > --------------------------------------------------------------- > > Name: FILE.HTM > Part 1.2 Type: Hypertext Markup Language (text/html) > Encoding: base64 The way I test a ir remote is to use a transister radio. I tune it mid range on the FM band to a place where there is no station, Turn the volume up so I can hear the white noise. Then I key the remote. You can hear the ir interference on the radio. Ralph

> WILLIE W. HO wrote: > > Hi there, > > Is there a kind of IR LED can also emit visible light like LED ? > How do I know that it's working or not after assembly to a PCB > board without measuring the polarity ? > If you know someone with a video cam-corder, borrow it. Turn on the IR LED, and point the cam-corder at it. Look into the viewfinder of the camcorder. For some reason, color cam-corders show IR LED's blue. BBut in any case, even a black and white camera will see an infra red LED. Russell Hedges

Van: WILLIE W. HO <spam_OUTmtlTakeThisOuTpub.zhongshan.gd.cn> Aan: .....PICLISTKILLspam@spam@MITVMA.MIT.EDU Onderwerp: IR LED Datum: woensdag 24 maart 1999 3:29 > Hi there, > > Is there a kind of IR LED can also emit visible light like LED ? > How do I know that it's working or not after assembly to a PCB board without > measuring the polarity ? Look at it with a Video or CCD-camera. You should be able to see it flicker ... A (visible-light-emmitting) LED in _series_ could be another option. Greetz, Rudy Wieser

On Wed, 24 Mar 1999 00:32:26 -0800 Russell Hedges <russellhKILLspamhome.com> writes: >For some reason, color cam-corders show IR LED's blue. BBut in any >case, >even a black and white camera will see an infra red LED. Most color cameras have an anti-IR filter that blocks most of the IR. Usually it will still see a LED if pointed directly at it. Black and white cameras, not having any filter, are quite sensitive to near-IR from a LED. Also, night-vision equipment is usually sensitive to IR. You could buy or make a test IR detector with a photodiode or phototransistor connected to a visible LED, meter, or scope. There are also little cards made of special paper that glows orange when exposed to IR. Radio Shack used to sell them. ___________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com/getjuno.html or call Juno at (800) 654-JUNO [654-5866]