Converting period to Miles Per Hour

[Acetronics2]

Hi, Roy

1 wheel turn = 78.4 inches ... 5 bolts per turn

15.68 inches per pulse

1 mile is 63360 inches ... = 4040.816 pulses ( or 1 034 449 / 256 ... )

Done.

BTW ... does PBP Silver edition support the 46K22 ???

Alain

[Amoque]

Adding to Alain's expert analysis of distance.

RATE * TIME = DISTANCE, so... If 1 rotation takes 1 second then:

78.4 inches per second * 60 seconds = 4704 inches per minute. Multiply by 60 minutes to find distance per hour = 282,240 inches per hour or (dividing by 63,360 inches in one mile) = 4.45 MPH.

-OR-

[INCHES PER SECOND] * 3600 / 63360 = MPH

The above works only if the inches in one second are known. So, we must also know how to calculate the [INCHES PER SECOND]... Take the example of .4 seconds per rotation:

To calculate the [INCHES PER SECOND] multiply the reciprocal (1/X) of rotation period by the wheel diameter (78.4) to find:
1 / .4 = 2.5 rotations per second. 2.5 rotations (2.5 * 78.4) = 196 inches = [INCHES PER SECOND]. Now, complete the formula above (11.136 MPH) . Not remarkably this is 2.5 times the 4.45 MPH figure calculated for 1 rotation per second - allowing for rounding.


DISCLAIMER: The accuracy of these figures is only as correct as the time base from which they are figured. IE: timer overflow vs atomic clock.

[Acetronics2]

Hi, Amoque

Here we meet the precision problem with reciprocal calculations ....

sooo ... I would suggest, depending on the pulse count or the pulse duration, to choose the value that gives the minimum error to the result.

I.E. ... @ low speed, let's consider pulse duration ( big number gives better resolution ) and @ High speed let's consider the pulse count.

But ... as our "friend" didn't tell what he wants to measure ( snail or car racing ??? ) ...

Alain

[Amoque]

Hope is not lost, Alain. He may be back as he left his answer here - only leaving his wallet would motivate him to return more promptly. We need only wait for him to notice then... nab him and we shall have answer!

It may be we may cajole him into revealing where the [leftover] pumpkin pie is hidden as well!

[Acetronics2]

http://sfodesigns.com/aboutsfodesigns.html

that could match the question ... and create some ...

Alain

[SFOdesigns]

http://sfodesigns.com/aboutsfodesigns.html

that could match the question ... and create some ...

Alain

Hi,

as always, I'm either giving too much information, or not enough....

This is the rear wheel of a motorcycle. The bolts, 5 in all, mount the rear pulley (belt drive) to the wheel. The circumference I provided is an actual measurement with the rider mounted. I realize that tire pressure, load, and temperature all have an effect on circumference, but i'm not that worried.

The speed can reach 100 mph in actual riding.

Thanks,

Roy

[Acetronics2]

Hi,

as always, I'm either giving too much information, or not enough....

This is the rear wheel of a motorcycle. The bolts, 5 in all, mount the rear pulley (belt drive) to the wheel. The circumference I provided is an actual measurement with the rider mounted. I realize that tire pressure, load, and temperature all have an effect on circumference, but i'm not that worried.

The speed can reach 100 mph in actual riding.

Thanks,

Roy

mhhhhh ...

belt driven ??? ...

or it's one of these awful Harleys ... or it's a real vintage lovely one ! ( a steam powered one ??? )

100mph ... a bit over 40k pulses an hour

11, ... Hertz @ Maximum ... then, the pulse duration method is to use.
i'd use some soft dividers switching for the basetime choice vs speed.

the 46K22's Timer 0 looks fine for that purpose ...

But do not ask too much to a Kawa H1 owner ( yesss ... the 3 smoking cylinders !!! ) to do for a ... Harley ...

Alain