Math Question (Please Help)

Archiver

Hello,

I am working on a project for my car. I am planning to make a tachometer. I got
on to a few sights and got allot of info. I plan to make it using National's "
LM2917 ",an A/D converter, and the BS2p.

My problem is that National has in the typical applications has two tachometers,
and one says that 300Hz = 6000 RPM ( 6 cylinder Engine ). and that the other one
says 400Hz = 6000 RPM ( 8 cylinder engine ), but the one that I need (6
cylinder) is for current driven meter, I need the Voltage driven meter.

My question is, If 6V = 400Hz, then ?V = 300Hz. And how do you come up with it?

Thanks
AC


[noparse][[/noparse]Non-text portions of this message have been removed]

Archiver

Anthony...I cannot comment on the specifics of your question but I would
like to ask if you have ever installed an aftermarket tach on a car
before....... I have, and I learned alot about how they work. I think if
you even went to an auto parts store and read the instructions..( for free )
you might gain some insight to your project. Remember that they are trying
to make one tach that fits the largest variety of vehicles......since they
do that, they will undoubtedly have to give up some info on how its
done...in the form of...... " if you have a 4/8 cylinder, use the blue
wire" "all 6 cyl use the green wire" "3 and 5 cylinders...go away"

hope that helps


Dave

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Original Message

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From: "Anthony Conti" <aconti@s...>
To: <basicstamps@yahoogroups.com>
Sent: Thursday, July 04, 2002 1:11 AM
Subject: [noparse][[/noparse]basicstamps] Math Question (Please Help)


> Hello,
>
> I am working on a project for my car. I am planning to make a tachometer.
I got on to a few sights and got allot of info. I plan to make it using
National's " LM2917 ",an A/D converter, and the BS2p.
>
> My problem is that National has in the typical applications has two
tachometers, and one says that 300Hz = 6000 RPM ( 6 cylinder Engine ). and
that the other one says 400Hz = 6000 RPM ( 8 cylinder engine ), but the one
that I need (6 cylinder) is for current driven meter, I need the Voltage
driven meter.
>
> My question is, If 6V = 400Hz, then ?V = 300Hz. And how do you come up
with it?
>
> Thanks
> AC
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
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