J.C. Whitney AFR meter
Randall
ryoung at navcomtech.com
Thu Jan 27 22:56:15 GMT 2000
Rex Weatherford wrote :
>
> I was looking at the schematic for Dave's meter and had a few
> questions.
>
> What is the LM3914?
It's an integrated circuit made by National Semiconductor, designed to
create a bar graph display with a minimum of external components.
National's data sheet is at http://www.national.com/pf/LM/LM3914.html . The
part should be available from most full-line electronics supply houses
(which leaves out Radio Shaft).
>
> It says I can buy a meter like this from JC whitney for $20? Is that
> true?
Not quite. Current price is $36. See
http://www.jcwhitney.com/product.jhtml?CATID=4571 .
>
> How are these used... I know that my ECM looks for values
> between .100v
> and 1.1v. And that my EGO sensor has to warm up before this means
> anything. Correct?
Basically. The LM3914 uses 1.2v as the reference (full scale), I assume the
Whitney meter does the same. I believe the EGO sensor output is basically
meaningless above about 0.9v.
Randall
----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org
More information about the Diy_efi
mailing list