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enter image description hereI've studied the basic principle of the dc generator which is with the single loop example.

Right here it's the example for the motor but the generator works the other way around. I'm aware of how it works anyway.

My problem is I fail to see the loops in the following diagrams and the actual generators.From the pictures I've seen I only see coils going from a slot to the commutators. The image on the right is the actual image and the one on the left is used for ease. enter image description here

Let's take coil A for example. It goes from slot 1 to the commutator and from commutator to slot 3. So is coil A actually 2 coils? Where is the loop of coil A? I've been searching for quite some time but I can't find an explanation. Is the coil going behind the picture and coming of slot 3 to make a loop? Maybe I don't understand how the coils are placed.

Again, my problem is the transition from the basic example to the actual generator. You can clearly see here coils wrapped around and not loops. Is each one connected to the wrapped coil across? enter image description here

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Ignore Fig 4.7, it's only a kind of schematic, showing teh electrical connections not the physical reality of the coil.

Looking at Fig 4.9 and taking coil A as you asked, it appears as a tiny circle in slot 1, and another tiny circle in slot 3. So it is going into he page in slot 1, and coming out of the page in slot 3 (or vice versa). The other two circles in those slots represent coil C.

EDIT : see comment for how Fig 4.9 actually works. And rather than try to keep up with the evolving question, I'll point out that when you analyse the windings in the photo you'll find the coils are arranged in sets of 3 (every third coil is connected together) - you'll need to learn a bit about 3 phase AC electricity before you understand this one.

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  • \$\begingroup\$ So coil C does the opposite. The loop of coil A is in the page and the loop of coil C is out the page.And each loop covers half the space between the magnets and not the whole space as shown in the picture with one loop. Is that how it is? \$\endgroup\$
    – John Katsantas
    Feb 21, 2017 at 10:19
  • \$\begingroup\$ Right. But notice that both ends of A are connected to brush X at the moment, and both ends of C are connected to brush Y, so neither is generating force. You chose the wrong coil to start with! Now trace B and D. Note that B runs from b via x to y to c, while D runs from d via y to x to a, so D is opposed to B. But as it is wound the opposite way round, (one clockwise, one anti) they both produce force in the same direction. \$\endgroup\$
    – user_1818839
    Feb 21, 2017 at 10:30

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