DC Generator: Equations & Graphs

[LovePhys]

Hello everyone,

I found on this website http://spiff.rit.edu/classes/phys213/lectures/lenz/lenz_long.html a very good explanation for AC generators. Particularly I am considering these two images:

And

I found those equations and graphs are quite interesting and wish to make a "change" so that they are valid for DC generators.

My thinking is that: For the sine graph, I have to flip the negative part to make it positive. It will look something like this:

Also, the equations for magnetic flux, the current and also the voltage basically stay the same but should be taken as the absolute value.

Can anyone please correct me if I wrong?

Many thanks,
LovePhys

 

[truesearch]

You are on the right track. The main difference between an AC and a DC generator is the means of making connections to the coil.
In an AC machine 'Slip rings' are used to preserve the AC voltage and current. In a DC machine a 'commutator' is used to make the voltage and current in one direction, just as you have drawn in your last diagram.

 

[LovePhys]

Thank you very much truesearch!