<div>Dear Deepak , </div>
<div>Then you are wrong person trying out your hand on ronja !! use a simple signal generator or fucntion generator to test the LED !!</div>
<div>Which city are you in ? Superflux LED are available in India</div>
<div>PK Yaduvanshi<br><br> </div>
<div><span class="gmail_quote">On 21/03/2008, <b class="gmail_sendername">Deepak Mishra</b> <<a href="mailto:xask.linus@gmail.com">xask.linus@gmail.com</a>> wrote:</span>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">Sorry man , but I do not know how to generate a pulse !<br>What signal source do I use ?<br>I have no practical experience in electronics<br>
<br>Regards,
<div><span class="e" id="q_118d1ea5d92b6ae3_1"><br>Deepak<br><br>
<div><span class="gmail_quote">On 21/03/2008, <b class="gmail_sendername">Arun Krishnan</b> <<a onclick="return top.js.OpenExtLink(window,event,this)" href="mailto:arunk@speedpost.net" target="_blank">arunk@speedpost.net</a>> wrote:</span>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0pt 0pt 0pt 0.8ex; BORDER-LEFT: rgb(204,204,204) 1px solid">Hi Deepak,<br><br>I don't think a 555 can clock to the 10Mhz you'll need to test your LED<br>
at.<br><br>But I'm thinking you can measure the rise and fall time just by a single<br>pulse and a CRO that has enough resolution.<br><br><br>Regards,<br>Arun<br><br><br>----- Original message -----<br>From: "Deepak Mishra" <<a onclick="return top.js.OpenExtLink(window,event,this)" href="mailto:xask.linus@gmail.com" target="_blank">xask.linus@gmail.com</a>><br>
To: "Twibright Ronja" <<a onclick="return top.js.OpenExtLink(window,event,this)" href="mailto:ronja@lists.pointless.net" target="_blank">ronja@lists.pointless.net</a>><br><br>Date: Fri, 21 Mar 2008 20:00:19 +0530<br>
Subject: Re: [Ronja] Testing switching time of an LED<br><br>Thanks ,<br>I had this basic idea in mind that I must apply a fast input square wave<br>signal to the led and check the output using a scope on the photo diode.<br>
<br>But the basic problem is I am such a new bie that I am not sure if i<br>should<br>connect<br>the photo diode directly to the oscilloscope and with resistor in series<br>or<br>what ??<br><br>And how do i generate a square wave signal of the desired frequency ?<br>
I have heard of the 555 timer, do I have to use the breadboard ?<br><br>I good with software, but not so good at hard ware, I hope you get the<br>idea<br>?<br><br>Thanks anyway!<br>Cheers,<br>Deepak<br><br><br>On 21/03/2008, Arun Krishnan <<a onclick="return top.js.OpenExtLink(window,event,this)" href="mailto:arunk@speedpost.net" target="_blank">arunk@speedpost.net</a>> wrote:<br>
><br>> Hi Deepak,<br>><br>> You'll need to hook up the LED to a simple square wave generator and use<br>> a fast photodiode connected to a CRO to measure how fast it is<br>> switching. There are other methods where you could program something<br>
> like a microcontroller to measure it, but the easier way would be to use<br>> a CRO.<br>><br>> Regards,<br>> Arun<br>><br>><br>><br>> ----- Original message -----<br>> From: "Deepak Mishra" <<a onclick="return top.js.OpenExtLink(window,event,this)" href="mailto:xask.linus@gmail.com" target="_blank">xask.linus@gmail.com</a>><br>
> To: "Twibright Ronja" <<a onclick="return top.js.OpenExtLink(window,event,this)" href="mailto:ronja@lists.pointless.net" target="_blank">ronja@lists.pointless.net</a>><br>> Date: Fri, 21 Mar 2008 19:13:44 +0530<br>
> Subject: [Ronja] Testing switching time of an LED<br>><br>> Hi all !,<br>><br>> As always, I am having trouble find the LED HPWT-xxxx-xxxx.<br>> So I am going to test some LED manufactured in my country (India) easily<br>
> available at low costs.<br>><br>> I mainly want to test the rise/fall time of the LED and its not in the<br>> datasheet.<br>><br>> I am an electronics newbie, so could somebody point me to an electronic<br>
> circuit and a way to measure<br>> the rise and fall times of the LED ?<br>><br>> Cheers,<br>> Deepak<br>><br>><br>> --<br>> Twibright Ronja mailing list <a onclick="return top.js.OpenExtLink(window,event,this)" href="http://ronja.twibright.com/" target="_blank">http://ronja.twibright.com</a><br>
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