Lambda sensors - Where, Why and how Much ?

[Len Sabatine]

At 11:48 AM 6/8/00 -0700, you wrote:
>On Thu, 8 Jun 2000 08:35:29 -0700 (PDT), Squash <realsquash at yahoo.com>
>wrote:
> >--- Len Sabatine <sabatine at epix.net> wrote:
> >> > > -- One of those wires goes to the Ho2s [ Heater ] One of the ground
> >> > wires is redundent.
> >>
> >>          Len
> >Then why did they put 2 ground wires in?
>
>Good EE practice. The heater lines carry beau coup current, multiple
>amps, you don't want any possible contact problems causing the reference
>for your O2 sensor to levitate. Hence, use a separate "signal gnd" for
>the smallish O2 sensor signal. You'll see this practice of separate
>sensor reference gnds showing up moreNmore in automotive, as the signal
>levels come down, and the noise margins become more an issue.
>
>The hysteresis in the older one-wire O2 sensor circuits had to be set
>much larger, AND some designs I've seen, the actual signal threshold
>floats around, centered between the min & max O2 swings, just because
>the gnd reference for those earlier sensors was potentially so poor and
>floaty. Hey, it's now better design thru better wiring!
>
>Gar
>        AMEN !!!!

  Len


>----------------------------------------------------------------------------
>To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
>in the body of a message (not the subject) to majordomo at lists.diy-efi.org

----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org