NetNews Usenet Archive 1992 #16/NN_1992_16.iso/spool/rec/autos/tech/10178

Text File | 1992-07-27 | 1.6 KB | 32 lines

Newsgroups: rec.autos.tech
Path: sparky!uunet!darwin.sura.net!mlb.semi.harris.com!billy.mlb.semi.harris.com!jws
From: [e-mail] (James W. Swonger)
Subject: Re: Fuel Pump Relay
References: <[e-mail]>
Date: Mon, 27 Jul 1992 12:49:26 GMT
Nntp-Posting-Host: billy.mlb.semi.harris.com
Organization: Harris Semiconductor, Melbourne FL
Sender: [e-mail]
Message-ID: <[e-mail]>
Lines: 19

 Cars with electronic fuel injection (EFI) use an electric fuel pump to
run gasoline at high pressure to the injectors. Some carbureted cars also
use electric pumps. These pumps use a fair amount of current. The electrical
loads in new cars are too high to run directly off the small ignition
switch, so makers have gone to using relays for the heavy-demand loads and
use the ignition circuit for the control signal to the relays instead of
direct power.

 A relay is an electro-mechanically activated switch. Instead of manually
moving a lever or rocker to open and close the contacts, you apply a small
amount of current to the relay coil. The coil pulls on the contactor arm
magnetically and the arm moves from one set of contacts to the other. The
arm and contacts are able to pass much more current than the coil requires.
Because of this you can control a lot of current with a little.
--
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#Irresponsible rantings of the author alone. Any resemblance to persons  #
#living or dead then yer bummin. May cause drowsiness. Alcohol may inten-#
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