[Diy_efi] GM TBI electrical details

Thu Dec 16 08:25:16 GMT 2004

--===============47324744643224337==
Content-Type: multipart/alternative;
	boundary="-----------------------------1103185298"

-------------------------------1103185298
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit

The 5 Volt rail is derived internally in the ECU for the logic circuitry  
inside, including the microprocessor.  A regulator chip accepts the  vehicle's 
12v (nominal) supply and "drops" it to 5v which is the maximum that  normal 
logic devices, by long-established convention, tend to use.  

The injector driver transistors would use a signal from the logic circuitry  
swinging from ground to +5volt and translate this to an "on/off" conductive 
path  for the "ground return" from 12volt through the injectors to ground.  This 
 is a simplification, but not much of one.  There are plenty of basic  
electronics textbooks and application notes out there if you scratch around a  bit.  
Enjoy!

Will
G0OPL

-------------------------------1103185298
Content-Type: text/html; charset="US-ASCII"
Content-Transfer-Encoding: quoted-printable

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; charset=3DUS-ASCII">
<META content=3D"MSHTML 6.00.2900.2523" name=3DGENERATOR></HEAD>
<BODY id=3Drole_body style=3D"FONT-SIZE: 10pt; COLOR: #000000; FONT-FAMILY:=20=
Arial"=20
bottomMargin=3D7 leftMargin=3D7 topMargin=3D7 rightMargin=3D7><FONT id=3Drol=
e_document=20
face=3DArial color=3D#000000 size=3D2>
<DIV>The 5 Volt rail is derived internally in the ECU for the logic circuitr=
y=20
inside, including the microprocessor.&nbsp; A regulator chip accepts the=20
vehicle's 12v (nominal) supply and "drops" it to 5v which is the maximum tha=
t=20
normal logic devices, by long-established convention, tend to use.&nbsp; </D=
IV>
<DIV>&nbsp;</DIV>
<DIV>The injector driver transistors would use a signal from the logic circu=
itry=20
swinging from ground to +5volt and translate this to an "on/off" conductive=20=
path=20
for the "ground return" from 12volt through the injectors to ground.&nbsp; T=
his=20
is a simplification, but not much of one.&nbsp; There are plenty of basic=20
electronics textbooks and application notes out there if you scratch around=20=
a=20
bit.&nbsp; Enjoy!</DIV>
<DIV>&nbsp;</DIV>
<DIV>Will</DIV>
<DIV>G0OPL</DIV></FONT></BODY></HTML>

-------------------------------1103185298--

--===============47324744643224337==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

_______________________________________________
diy_efi mailing list
diy_efi at diy-efi.org
http://lists.diy-efi.org/mailman/listinfo/diy_efi

--===============47324744643224337==--