Vanagon EuroVan
Previous messageNext messagePrevious in topicNext in topicPrevious by same authorNext by same authorPrevious page (August 2017, week 1)Back to main VANAGON pageJoin or leave VANAGON (or change settings)ReplyPost a new messageSearchProportional fontNon-proportional font
Date:         Wed, 2 Aug 2017 15:48:23 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: Time Delay LED Lighting Circuit
Comments: To: Neil N <musomuso@gmail.com>
Comments: cc: Alistair Bell <albell@shaw.ca>
In-Reply-To:  <CAB2Rwfie0Yn=VWqPtwadk83_W7cirQfVWSiYfiLHa-6sfWd2bg@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"

Osram DE3423 LED festoon lamp is one watt. If you want ten seconds of fading light at average half brightness that would require something like five watt seconds of storage in your capacitor. Say six or seven because of the threshold voltage of the LED. WS = C x V^2 / 2, so C = WS / (V^2 / 2). So C = 7 ws / (12V^2 / 2) = 7 / 72 = ~0.1 farad or 100,000 uF.

Here's one that would serve. It's nominal 40 mm diameter and 80 mm length, and it costs ten bucks US in onesies. https://www.digikey.com/product-detail/en/united-chemi-con/ESMH160VSN104MA80T/565-2624-ND/757837

Yrs, d

On Wed, Aug 2, 2017 at 1:32 PM, Neil N <musomuso@gmail.com> wrote:

> Thats great! So about 5 seconds eh? I'd think that for a festoon the > cap(s) would have to be much bigger. But maybe 3 of those small LED's > would be plenty? >


Back to: Top of message | Previous page | Main VANAGON page

Please note - During the past 17 years of operation, several gigabytes of Vanagon mail messages have been archived. Searching the entire collection will take up to five minutes to complete. Please be patient!


Return to the archives @ gerry.vanagon.com


The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.

Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.