Voltage output for ideal diode (solutions wrong?)

1. Feb 2, 2013

pyroknife

I'm looking at some solutions for a problem I found. This link is http://www.etcs.ipfw.edu/~lin/MET487/2011-SumII/Lectures/Hw3_Sols-MET487-Sum2011.PDF
It's page 4 problem 3.1.

Okay so V_in is given to be 10cos(2∏t), but their graph for V_in makes no sense to me and consequently, V_out seems wrong as well.

Am I missing something here or is their graph for V_in totally off? The magnitudes are right but their period seems a factor of 2 off.

2. Feb 3, 2013

ehild

You are right, the period is wrong.

ehild

3. Feb 3, 2013

pyroknife

Thanks. Any clue what they were doing by finding frequency? I don't see any point in doing that.

4. Feb 3, 2013

ehild

The time dependence of an AC voltage is U=Acos(ωt). The input voltage is U=10cos(2pi t). So what is the angular frequency ω? How is it related to the frequency and to the time period?
The scaling in the picture is wrong.

ehild

5. Feb 3, 2013

pyroknife

Yeah I know that the relationship between angular frequency and frequency is
angularfrequency=2*pi*frequency
and that period=1/frequency.

I just don't understand why they went through the hassle of calculating frequency to draw a simple sinusoidal graph. Frequency was never asked to be calculated, so i didn't see the point in calculating it unless they somehow saw this as an easier way of drawing a simple cosine function.

6. Feb 3, 2013

ehild

They needed to graph time dependence of the output voltage. (But they did it wrong)
ehild