Freqout & pwm

Archiver

I was looking up some frequency stuff in my BS1 manual, and I noticed that (for
the BS2 only) freqout generates a sine wave using a pwm algorithm. My question?
Where, on the internet, can I find information on algorithms? I have not gotton
that far in my education and and seeing that word more and more in electronics.
Any help is always appreciated.


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Archiver

>I was looking up some frequency stuff in my BS1 manual, and I
>noticed that (for the BS2 only) freqout generates a sine wave using
>a pwm algorithm. My question? Where, on the internet, can I find
>information on algorithms? I have not gotton that far in my
>education and and seeing that word more and more in electronics. Any
>help is always appreciated.

Hi astro,

An algorithm is simply the programming steps required to achieve a
desired result. A recipe. A way to "skin the cat". Often there is
more than one way.

One objective of PWM is to have an output turned ON part of the time
and OFF part of the time, in such a way that the average is some
desired percentage of the time. There are several ways to do it.
Say you want an average value of 50% over a time period of one
second. One way is to leave the output ON for 1/2 second and OFF for
1/2 second. Alternatively, turn the output ON and OFF one hundred
thousand times in that same second. (that is close to the way the
stamp does it.) Or something in between. You don't even have to
have the ON and OFF spaced evenly across the one second. You could
turn the output ON and OFF 100,000 times in the second, but bunch
them up so that the average value looks like a sine wave with a
frequency of, say, 400 hertz. (That is how the stamp does Freqout).

http://www.emesystems.com/BS2PWM.htm <--- more on PWM algorithm.


-- regards,
Tracy Allen
electronically monitored ecosystems
mailto:tracy@e...
http://www.emesystems.com/BS2PWM.htm <--- more on PWM algorithm.