Sin waveform

can any one tell me about this equation ...


v=Vmsin(wt)..

here vm =peak voltages
w=omega 2pif
what is t and v?
and please explain every thing seperately..

V is the DC offset of the signal
t is time, it stars from t=0 seconds and rises
omega=2 x pi x f, where f is the frequency of the signal

you mean t is a time period of the signal

and please tell me a difference between dc offset value and rms value????

Looks this place: http://au.answers.yahoo.com/question/index?qid=20120306073407AAcTp0d

't' is the instantaneous time (in seconds if 'f' is in 'cycles per second' or 'Hertz' [Hz]).

Should be written as v(t) = Vm Sin(wt)

A sinewave is a function of time thus v(t) , remember this is actually a mathematical equation to describe a sine function.

Anyway Vm is the maximum amplitude of the sinewave. Vp-p would be the peak to peak amplitude of the sinewave

W is the radian frequency thus 2*pi * f where f is the frequency in Hertz

t is the variable of the equation - which is to say it is the instanteous value of time.

so therefore v(t) is the instanteous value of the voltage at a given time (t)

If the sinewave were to have a dc offset then the equation would be written as v(t) = Vdc + Vmsin(wt)

Dear sir i want to ask one thing only if t is an instantaneous value or voltage is a function of t means in 0.02 second which is a time period of sin waveform voltage value start from 0 and goes to its peak value and then become zero then again goes in negative peak before become to zero this all process occur so fast that we cant see with our eye??? m i right sir???

Dear sir i want to ask one thing only if t is an instantaneous value or voltage is a function of t means in 0.02 second which is a time period of sin waveform voltage value start from 0 and goes to its peak value and then become zero then again goes in negative peak before become to zero this all process occur so fast that we cant see with our eye??? m i right sir???

First of all, it depends on what you're looking at. If it's a wire impinged upon by the sinewave voltage or a bunch of electronic components similarly impinged (none of which convert the electrical energy to light) then you aren't going to "see" anything no matter what the frequency is.

If you are looking at something like a light whose brightness is being modulated by the sinewave voltage, then if the frequency is below around 70Hz, you are likely to begin to see it (especially in your peripheral vision). And, below around 30 Hz you're even more likely to see it. At 10 Hz and below, it's pretty much a certainty that anyone with vision will see the light's intensity fluctuate up and down.

If it is a scope you're looking at, then only the capture rate of the scope is an issue. Though, what you will be "seeing" there is a history of the sinewave event.

As steve says you are not going to see anything as the time to complete 1 cycle at 60 hertz is 16.67millisecs or at 50 hertz it would be 20 millisec. So at 50 hertz - after 5 millisec the voltage will hit a positive peak, after 10 millisec the voltage would be zero and at 15 millisec the voltage would be at the negative peak and at 20 millisec the voltage is back to zero and the whole thing repeats it self. as steve said as the frequency gets lower so can start to see the strobing effect. If you got the frequency low enough you could actually what is going thru the cycle

thank you so much now can you please tell me one thing what is a difference between Dc offset value and avg value ???
because avg value of full wave rectification is like 2vm/pi and as said Calinoaia Valentin V=Vm sin(wt) ) this V is called DC offset value???

DC offset value is only in reference to the sinewave - when a sinewave has an average value then it is called dc offset. The average value of a sinewave is zero when when it is not then it is said to have a dc offset

Another term for "DC offset" is "DC component". If the sinewave swings just as much above zero volts as it does below zero volts, then it has no DC component (or DC offset). It's purely AC. But, if the magnitude of the sum of the positive portion of the wave is different than the magnitude of the sum of the negative portion (i.e. take the "average" of the waves instantaneous levels over one cycle), then the wave is "AC with a DC component" or "AC with a DC offset".

This occurs when a DC voltage is added to an AC voltage.

BUT, the "average" spoken of , above, is the _algebraic average_. The the _average value_ that you asked about, is different. That is the average of the _absolute value_ of the instantaneous levels over one cycle. For a sinewave it's 0.637 times the _peak value_.

This explains it very well:

http://www.allaboutcircuits.com/vol_2/chpt_1/3.html

A sine wave or sinusoid is a mathematical curve that describes a smooth periodic oscillation. A sine wave is a continuous wave. It is named after the function sine, of which it is the graph. It occurs often in pure and applied mathematics, as well as physics, engineering, signal processing and many other fields.

any update? official site

This comment refers to a credit card site, please treat as spam.

Consider it done -- thanks David -- Max