frustrating diodes....

[eriatarka]

I have attached a worksheet I am trying to get through and seem to be having a very, very difficult time.

If anyone could walk me through this I would really appreciate it!

Thank you in advance.

 

[mneary]

Why are the graphs all +1 to -1 when the transformers are 28Vrms, 58Vpk, and 22Vrms? You don't have room to draw the answers to the problems. Why does the third problem show the transformer as 22Vrms in the schematic and the text says 13Vrms? Are the voltages for the whole windings end to end or are they per winding (example 1 is it 28-0-28 or 14-0-14)?

Your instructor needs to be in your class.

 

[Hero999]

I assumed all the graphs were normalised to 1V peak but that should be noted.

The 13V, totally contradicts the diagram. I would answer the question for both 13V and 22V and make a polite note of the error on the sheet.

 

[kevporter@hotmail.com]

The +1 and -1 in the graph do not represent a voltage they are there as a indicator of constant, this shows that the transformer is centre tapped. The main calculations are to do with the RMS to Peak and Peak to Peak voltages.

Volts peak = volts RMS times 1.414
Volts RMS = volts peak times 0.7071

For sine waves
To calculate the RMS value of a sine wave, multiply the peak value by 0.707. The peak value is, of course, one half the peak-to-peak value. To go the other way, reverse the order of operations. That is, if you're starting with an RMS value, divide by 0.707 and then multiply by two to get the p-p value. Another way to convert from RMS to p-p is to multiply the RMS value by two square roots of two: RMS x 2 x SQR(2).


Or more simply, to convert from RMS to peak to peak voltage:

(RMS x 1.414) x 2=P-P

For example:

120vac x 1.414= 170vac
169.68vac x 2 = 339.36vac P-P




Here is a description of the circuit here : The conventional full-wave rectifier

I agree with the point about circuit number 3, where the diagram indicates 22V rms and the question states Esecondary =13V rms.

Do the calculation for the one set of circumstances but indicate which value you used to calculate the results.

It's been over thirty years since I did these calculations at college, so forgive me if my answer is slightly vague.

Regards
Kev