Thanks ,<br>I had this basic idea in mind that I must apply a fast input square wave 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 should connect <br>
the photo diode directly to the oscilloscope and with resistor in series or 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 idea ?<br><br>Thanks anyway!<br>Cheers,<br>Deepak<br><br><br><div><span class="gmail_quote">On 21/03/2008, <b class="gmail_sendername">Arun Krishnan</b> <<a href="mailto:arunk@speedpost.net">arunk@speedpost.net</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
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 href="mailto:xask.linus@gmail.com">xask.linus@gmail.com</a>><br>
To: "Twibright Ronja" <<a href="mailto:ronja@lists.pointless.net">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 href="http://ronja.twibright.com">http://ronja.twibright.com</a><br>
<a href="mailto:Ronja@lists.pointless.net">Ronja@lists.pointless.net</a><br> <a href="http://pointless.net/mailman/listinfo/ronja">http://pointless.net/mailman/listinfo/ronja</a><br> </blockquote></div><br>