Electricity & Megnetism

# Association of electrical generators in parallel

If like generators were connected in parallel, they would keep together the same potential difference U

It is common to put several batteries, that is, generators, in toys, TV controls, etc. In all these devices the batteries (generators) are placed in a series association. At no time do we come across an association of generators in parallel, this does not happen because no device works with its associated batteries in parallel, as there is no advantage in this association.

In this type of connection, all the poles of the batteries, that is, of the generators, must be connected to each other and all the negative poles too.

Let’s consider the figure above; let’s assume that all generators are the same, have the same electromotive force ε (emf) and also have the same internal resistance r .

Let’s assume that the intensity of the electric current that runs through the association is i , so we can say that the electric current in each of the generators is

Thus, the associated generators together maintain a potential difference U between the association terminals. For the equivalent generator we have:

For each of the association generators we have:

If we equate both equations, we get:

Performing the identity between the terms before the equality and after the equality, we have:

We can conclude from all this mathematics that in an association of equal generators in parallel, the electromotive force (ε) is the same, therefore, only the internal resistance decreases.