Vanagon EuroVan
Previous messageNext messagePrevious in topicNext in topicPrevious by same authorNext by same authorPrevious page (April 2010, week 3)Back to main VANAGON pageJoin or leave VANAGON (or change settings)ReplyPost a new messageSearchProportional fontNon-proportional font
Date:         Sun, 18 Apr 2010 19:13:01 -0700
Reply-To:     Mike Rocket J Squirrel <camping.elliott@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Mike Rocket J Squirrel <camping.elliott@GMAIL.COM>
Subject:      Re: The alternator issue
Comments: To: David Beierl <dbeierl@ATTGLOBAL.NET>
In-Reply-To:  <4bcb868a.292ce50a.39f5.ffffaea6@mx.google.com>
Content-Type: text/html; charset=ISO-8859-1

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type"> </head> <body bgcolor="#ffffff" text="#000000"> David Beierl wrote: <blockquote cite="mid:4bcb868a.292ce50a.39f5.ffffaea6@mx.google.com" type="cite">At 11:39 AM 4/18/2010, Janne Ruohom&auml;ki wrote: <br> <blockquote type="cite">Isn't this something what the diodes installed in parallel with the <br> relay coil are for, in transistor controlled circuits ? <br> </blockquote> <br> Hi Yanne -- yes, that's what the diode is for.&nbsp; It's reverse biased against the coil drive voltage, so it doesn't short out the coil; but when the circuit opens the collapsing magnetic field in the coil drives its input terminal negative trying to keep the current flowing.&nbsp; The diode is then forward biased and discharges most of the stored energy in the coil. <br> <br> A capacitor would lower the voltage of the spike, but store the coil energy which would then pass back and forth, stored as an electrical field in the cap and as a magnetic field in the coil as it gradually used up the energy.&nbsp; This is how the old Kettering (points-type) ignition system works, and why the points burn up rapidly if the capacitor fails open or is missing. <br> <br> Yours, <br> David <br> </blockquote> <font size="-1">David. The whole thing (above). Well-written. Probably too technical for most -- they will blank well before the second paragraph -- but tight and accurate. There's a lot to unwind in those sentences. </font><br> <br> <pre class="moz-signature" cols="72">-- Mike "Rocket J Squirrel" Elliott 84 Westfalia: Mellow Yellow ("The Electrical Banana") 74 Westrailia: (Ladybug Trailer company, San Juan Capistrano, Calif.) Bend, OR KG6RCR

</pre> </body> </html>


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.