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Topic: sensing the speed (noise) (Read 808 times) previous topic - next topic

anlemo

Hi everybody,

i'm sensing the speed of a wheel (bike) with a Dynamo (DC motor) and then i send the data to the serial port, the problem that i have is that the Dynamo(DC motor) is sending a lot of noise and because of that i can't get the correct data of speed.

there is a way with hardware and software to supress that noise?

deSilva

#1
Aug 31, 2010, 06:01 am Last Edit: Aug 31, 2010, 06:02 am by mpeuser Reason: 1
Quote
... is a way with hardware and software to supress that noise?

Yes, it is.
Best you start plotting the signal so we can have a look at the different situations, and explain how you tried to determine the velocity from that signal at the moment.

zoomkat

You might try some capacitors like below.

http://www.pololu.com/docs/0J15/9
Google forum search: Use Google Advanced Search and use Http://forum.arduino.cc/index in the "site or domain:" box.

deSilva

#3
Aug 31, 2010, 06:20 am Last Edit: Aug 31, 2010, 06:22 am by mpeuser Reason: 1
But a dynamo should produce AC not DC...

Looks like another " Guess and fail" game  ;)

Groove

Quote
But a dynamo should produce AC not DC

Maybe this is a language thing - in English, a dynamo is specifically a DC generator.
Per Arduino ad Astra

pluggy

Bicycle generators are commonly called dynamos (at least in blighty) despite them almost universally producing AC. Its a misnomer, just like central heating calorifiers are almost universally called 'boilers' despite them most definitely not being boilers.


Driving incandescent lamps it makes little difference if they are AC or DC.
http://pluggy.is-a-geek.com/index.html

anlemo

Problem solved, thanks..

i was a little confuse of the voltage of the dynamo, and it was AC,, so i did a rectifier bridge and a filter, so now works perfectly

deSilva

#7
Aug 31, 2010, 10:08 pm Last Edit: Aug 31, 2010, 10:09 pm by mpeuser Reason: 1
Quote
Maybe this is a language thing - in English, a dynamo is specifically a DC generator

Most foreigners - I think - are not aware of this. In the German language the term Dynamo is nearly exclusively used for the thing at bicycles.

In a more technical slang Dynamo would actually describe an AC generator, in contrast to Gleichstrommaschine which is explicitely DC (=Gleichstrom). In English it is vice versa: 'dynamo' is DC and 'alternator' is AC...

The term 'generator' is - in both languages - used unspecifically.

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