How many tappings are allocated for each equalizer ring_____________?
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Answer: A. number of pole pairs
Explanation
Equalizer rings connect equipotential points on the armature winding to balance circulating currents between parallel paths. The physical spacing between these connected points must span exactly one pole pair distance around the armature. Therefore, the number of tappings allocated for each equalizer ring corresponds directly to the number of pole pairs. Large lap-wound DC machines suffer from unbalanced magnetic fluxes under different poles due to minor mechanical asymmetries. Equalizer rings provide low-resistance bypass paths for circulating currents, preventing severe sparking at the carbon brushes. Pole pairs are calculated by dividing the total number of main magnetic poles on the machine stator by two.
Option B is incorrect because tappings are spaced at pole pair intervals rather than connecting every single pole consecutively. Option C is wrong since parallel paths dictate current capacity rather than determining the geometric spacing of equalizer tappings. Option D is incorrect because commutator segments vastly outnumber the pole pairs and serve a different electrical purpose.
- Subject
- Engineering
- Category
- Electrical Engineering
- Topic
- —
- Difficulty
- medium
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