THE MOTORIST CASE OF DYNAMO.

Northern Advocate, 17 September 1927, Page 15

THE MOTORIST

CASE OF DYNAMO.

SOME USEFUL HINTS,

From the mechanical point of view there is very little that can go wrong with the dynamo, for the armature, running on ball bearings, only requires an occasional drop of oil and the windings seldom gives trouble. But the commutator brushes need regular attention in order to ensure the maximum utilisation of current. As the brushes wear down the spring adjusters which keep them in contact with the commutator drum require to be regulated, aud, furthermore, the brushes should be removed from their holders

from time to time in order that the condition of the commutator may be inspected.

In course of time the surface of the commutator becomes blackened with a mixture of carbon particles and grease, this forming a conductor between the segments •which causes loss of electoral efficiency and the output of the dynamo drops. ' In this ease the remedy is quite simple, and merely consists in shaping a small piece of wood to slip easily in the place of one of the brushes, then covering it with a strip of fine glass paper. Emery cloth should never be used. As the engine is rotated the glass paper will remove all for-

eigu matter from the commutator, and thus allow the brushes to resume their duties in collecting all the current generated in the armature windings. The blackening of the commutator is generally clue to imperfect contact of one or more of the brushes, so while the. brushes are removed this point should receive due attention. Loose or worn driving belts are often responsible for loss in dynamo outputs, as also.arc short circuits; but the latter usually require the services of an expert electrician, for the average lorry-driver is hopelessly outclassed when it comes to diagnosing electrical faults.