A welding set requires a low voltage but very high current
PHYSICS · Multi-part · CBSE · Physics · Alternating Current · Alternating Current
Problem
A welding set requires a low voltage but very high current. A single-phase transformer connected to a 230 V, 50 Hz supply is to deliver 100 A at 15 V to the welding electrodes.
(i) Calculate the ratio of the number of primary turns to the number of secondary turns that the transformer must have, assuming it is ideal.
(ii) If the primary has 460 turns, find the exact number of secondary turns that should be wound.
(iii) The combined resistance of the windings causes the secondary terminal voltage to drop by 5 % of its no-load value when the full-load current of 100 A flows. Determine the secondary terminal voltage at full-load.
(iv) Compute the percentage voltage regulation of the transformer on this load.