[Diy_efi] tach input circuit

[Bevan Weiss]

Surely R7 should be high voltage surface mount as well?
Going by the same logic as R5 and R6...
And why the protection diode on the output signal??
Also, why is the MOSFET tied high via the diode.  That would mean that the
output is always held low... when the MOSFET is on, the cathode of the diode
is connected to ground via the MOSFET.  When the MOSFET is off, the cathode
of the diode is still connected to ground via the MOSFET just at a much
higher impedance...

What's the output actually for??
Is it supposed to be tied high externally in which case, why's the diode D2
there?

----- Original Message -----
From: <BVicknair at bjservices.com>
To: <diy_efi at diy-efi.org>
Sent: Wednesday, March 05, 2003 8:52 AM
Subject: [Diy_efi] tach input circuit


>
> Here is a board I did that works well on clean digital (1-7v) or nasty
coil
> tach signal. Note R5 and R6 are high voltage surface mount.
> The software can now do scaled/rpm pwm for variable aux valve control on
> dual fuel design.
> bv
>
> attached in rpm.pdf
>
> (See attached file: rpm.pdf)
>


----------------------------------------------------------------------------
----


> _______________________________________________
> Diy_efi mailing list
> Diy_efi at diy-efi.org
> http://www.diy-efi.org/mailman/listinfo/diy_efi
>

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