RE: 14.4 volts on the headlamps

["Cordeiro, Alan" <Alan.Cordeiro@mts.com>]

Hey DeWitt,

You DELETED the theory part that I sent you in my private E-mail,
but just posted the last para. to the whole list.

Like I said, lamp loads on lower voltage consume less current, but not
significantly ( as in proportion to the voltage reduction ) since a lower 
voltage gives a cooler filament, which has lower resistance, so
the net result is a smaller reduction in current.

And as I said, the Fan load is proportional the SQUARE of the speed, 
therefore a small speed reduction gives a GREATER current reduction,
( e.g. a 10% voltage reduction would give a 20% current reduction)
but on the freeway, or on cooler days, the fan hardly every runs anyhow.

Alan


	-----Original Message-----
	From:	DeWitt Harrison [SMTP:de@aztek-eng.com]
	Sent:	Friday, December 18, 1998 12:57 PM
	To:	Cordeiro, Alan
	Cc:	quattro@coimbra.ans.net
	Subject:	RE: 14.4 volts on the headlamps

	So, Alan, what is your theory?

	At 10:51 AM 12/18/98 -0600, you wrote:
	>DeWitt,
	>[ ... ]
	>The alternator size depends on the maximum output current, as
	>long as the voltages are about the same ( 13 volts vs. 14 volts)
	>[ ... ]
	>-----Original Message-----
	>From:	DeWitt Harrison [SMTP:de@aztek-eng.com]
	>On Thu, 17 Dec 1998 16:55:41 -0600, Alan Cordeiro wrote:
	>>>Yeah I know, one of my main beefs with older BOSCH alternators 
	>>>used in Audis...... they seen fat dumb and happy at 13.7 or
so....
	>>
	>>Now go figger out why BOSCH alternators used in Chrysler
	>>vehicles regularly give 14.2 or 14.3 volts.........
	>
	>My theory: Supplying 13.x volts instead of 14.x volts represents
	>a significant power savings and permitts the use of a relatively
	>small (cheap?) alternator for a given complement of electrical
	>equipment. [ ... ]