<all> home dyno kit??

[Chris Conlon]

At 08:24 AM 1/28/99 -0500, Dan Llewellyn2 wrote:

>level ground.  At least were I live, level stretches of road where
>you can get up to speed are rare.  If they incorporated the data
>from a G-field measuring device, like an Analog Digital ADXL05,
>you could calculate horsepower even if the road was not level.

One thing I was gonna mention is the Analog Devices ADXL202, a
second generation, 2 axis +/- 5g accelerometer. It's even easier
to use than the first one, and has either a PWM output (you set
the frequency) and/or a linear analog output, per channel. This
is so easy you can hook the PWM input up to an audio amplifier
and listen to the sound change with acceleration. (Freq is
constant but the timbre changes. Or a simple 555 circuit will
get you variable frequency.)  In the Analog Devices tradition
of annoying package options it's a surface mount, but it's
still better than the damn (TO-10?) round can thing the last
one was mounted in. For just playing around, Digikey sells an
adapter board (Surfboards, by Capital Advanced Technologies,
p/n 9210CA-ND) which you can solder the chip onto and has a row
of pins on the side. SIP-style, about $7. The acclerometers
are surprisingly cheap too, pretty sure they're $30 or less in
ones, samples available.

I've thought about trying to make a better G-Tech sort of thing
with these, but definite accurate HP measurement with suspension
loading plus nonflat ground is still beyond what you can do with
just one, I think. If my math was right anwyay. You can get close,
though, with a couple simplifying assumptions. Now if you had *2*
modules, mounted fore and aft... nah. An exercise for the reader.

   Chris C.