--- In Electronics_101@..., "Scott Thompson"
<electronguy@e...> wrote:
Just got a chance to browse the schematic.
Looks pretty comprehensive and will require further study, but
your input power connector is wired so that it shorts out the
battery.
Thanks for sharing,
Scotty
Doh! I put the battery+ to ground instead of the supply... Good
spotting ;)
I've actually done a lot of thinking about this circuit and I've
come to the conclusion that I have no idea how to effectively catch
the average peak vibration and non-average peak spikes.
I was thinking of putting a precision rectifier in the sensor box,
adding gain in the monitor box then splitting the signal into two.
Once would go straight to the ADC for measuring the highest spikes
while the other would go to a capacitor for electrical averaging of
the peaks. That way I can do the fast sampling for spikes without
the overhead of peak value discovery and averaging (20 samples per
wave thing) and just a single sample to find the average peak.
Sounds good in theory out now I have to figure out how to do it 8).
Probably use an OPA2340 to split the (rectified) signal into two and
add gain, then experiment from there.
Oh and, I did some experimenting with PWM signals through a long
cable. Without a resistor added, the signal was distorted. I added a
1K resistor and the signal came out a lot cleaner. Think I'm getting
a grasp of this cable capacitance problem. Its not so much added
noise from the enviroment as it is the cable capacitance distorting
the signal thats already there. Square waves turn into rounded
corner waves and the amplitude bounces around. Less current means
less capacitance effect, cleaner signal.
