<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body><div><div style="font-family: Calibri,sans-serif; font-size: 11pt;">Yes, it was a revelation to me when I discovered the cold resistance of a flasher bulb was maybe an ohm, yet the power on 12V was, say, 21Watts. It didn't take much deduction to work out its resistance at 2000 deg C must rise to around 6 or 7 ohms.<br><br>Dave.<br>UK VW Type 3 and 4 Club.</div></div><div dir="ltr"><hr><span style="font-family: Calibri,sans-serif; font-size: 11pt; font-weight: bold;">From: </span><span style="font-family: Calibri,sans-serif; font-size: 11pt;"><a href="mailto:jadney@vwtype3.org">Jim Adney</a></span><br><span style="font-family: Calibri,sans-serif; font-size: 11pt; font-weight: bold;">Sent: </span><span style="font-family: Calibri,sans-serif; font-size: 11pt;">04/11/2017 21:43</span><br><span style="font-family: Calibri,sans-serif; font-size: 11pt; font-weight: bold;">To: </span><span style="font-family: Calibri,sans-serif; font-size: 11pt;"><a href="mailto:type3@vwtype3.org">type3@vwtype3.org</a></span><br><span style="font-family: Calibri,sans-serif; font-size: 11pt; font-weight: bold;">Subject: </span><span style="font-family: Calibri,sans-serif; font-size: 11pt;">Re: [T3] Lights</span><br><br></div>On 4 Nov 2017 at 17:21, Dave Hall wrote:<br><br>> Thanks, Jim. I wondered how the bulb failure system worked. Further<br>> research is indicated.<br><br>Yeah, this was always a mystery to me, part of which was that there is a <br>second relay in our TS flashers that I couldn't explain. it didn't occur to me <br>until a few years later, when I was looking at SCR phase control switches <br>that I saw that they make special versions "for tungsten loads." I didn't <br>understand what that meant, until I remembered that light bulbs have huge <br>inrush currents, so the SCRs have to be rated for that. And that inrush <br>current would trigger the 2nd relay in our flashers.<br><br>I rebuilt a TS relay for someone on this list a few years ago, and I could <br>never get it to work right on the bench, because I was just loading it with a <br>resistor. I never heard how it worked on the car. If that person is reading this, <br>let me know how that worked. If there was/is a problem, I think I can improve <br>on it now. <br><br>If it worked, that would be good news, too.<br><br>-- <br>*******************************<br>Jim Adney, jadney@vwtype3.org<br>Madison, Wisconsin, USA<br>*******************************<br><br>_______________________________________________<br>VWType3.Org mailing list - type3@vwtype3.org<br>To unsubscribe or change subscription options, visit:<br>http://lists.vwtype3.org/listinfo.cgi/type3-vwtype3.org<br>If you need more help, contact: gregm@vwtype3.org<br></body></html>