Why does current stop flowing in a DC motor while the brushes reach the gap between the commutator? The gap between the two commutators is very small and the brushes should remain in contact with both commutators?!

Open in App

Solution

Dear student
When commutator brushes are touching (bridging) both commutator plates, resulting in a short-circuit. This short uselessly consumes power without producing any motion. In a low-current battery-powered demonstration this short-circuiting is generally not considered harmful. However, if a two-pole motor were designed to do actual work with several hundred watts of power output, this shorting could result in severe commutator overheating, brush damage, and potential welding of the brushes

Regards

Suggest Corrections

Similar questions

Q. What are brushes in an electric motor
Difference between split ring and slip ring
What is commutator

In the figure given below, a coil is placed between two permanent magnets and it is rotated with the help of an axle, on which two rings R1 and R2 are internally attached. B1 and B2 represents metallic brushes. G represents galvanometer.

The current flowing through the circuit reverses direction periodically, such a current is called alternating current. The current can be made direct by ___.

Q. A commutator with a diameter of 50 cm rotates at 600 rpm. For a brush width of 2 cm, the time of commutation is,

Q. A commutator having a diameter of 60 cm rotating at 400 rpm. If the time of commutation of commutator is 1.5 msec, the value of brush width will be ____ cm.

Q. Question 4
The essential difference between an AC generator and a DC generator is that:
(a) AC generator supplies direct current.
(b) DC generator has a commutator.
(c) DC generator supplies alternating current.
(d) AC generator has slip rings while the DC generator has a commutator.

Join BYJU'S Learning Program