Date:         Tue, 29 Jul 2003 10:21:17 -0400
Reply-To:     SStones <sstones@IDIRECT.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         SStones <sstones@IDIRECT.COM>
Subject:      Re: Alternative signal lights
Comments: To: Gnarlodious <gnarlodious@MAC.COM>
In-Reply-To:  <BB4B60EF.1BE30%gnarlodious@mac.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 11:23 PM 7/28/03 -0600, you wrote:
>Has anyone experimented with LED turn signal bulbs, the "twist & lock" 2
>filament type? Is such a thing made? Seems like a good idea . . .


In order for the turn signals to blink at the expected rate, the overall
resistance through both secondary circuits past the flasher relay has to be
approximately the resistance of the incandescent bulbs. That is why when a
filament burns out in a rear turn signal the flasher flashes so quickly.
The resistance in that half of the circuit goes up to near infinity, the
capacitor charges overly quickly and the flasher takes almost no time to blink.
The Low Amperage LED "bulbs" would cause the same problem as they're much
higher in resistance than a normal bulb (They'd have to have resistors
inside for the LEDs to be in a 12-14VDC circuit).
They would make great additional indicators, ie. for trailers or
side-marker blinkers because in parallel they wouldn't greatly reduce the
resistance of the overall circuit, but I think the blink rate would be way
too fast to use them instead of bulbs.