Question { Alstom, 6162 }

HI
SIR
PLEASE TELL THE DIFFERENCE OF WELDING TRANSFORMER AND
WELDING RECTIFIER AND WELDING INVERT ER AND WHICH PLACE IS
USED WHICH TYPE

Answer

Welding transformers are industry standards for welding.
they r step down transformers. they take 220,440 v & give
40, 50 volts. basically they are tap type, movable core &
movable coil types.
welding rectifiers convert ac current to dc current by
using bridge rectifiers.
welding inverters are modern technologies.welding
generators r bulky because the volume of the iron core used
is dependent upon the input frequency of current ( 50 HZ).
in inverters the input frequency of current is increased to
several thousands of Hz, as a result a core size is
significantly reduced. moreover using a single inverter
almost all types of weldings can be performed which is not
possible in case of welding transformenrs.

Question { Alstom, 6162 }

HI
SIR
PLEASE TELL THE DIFFERENCE OF WELDING TRANSFORMER AND
WELDING RECTIFIER AND WELDING INVERT ER AND WHICH PLACE IS
USED WHICH TYPE

Answer

in the above answer, i wrongly wrote welding generator
which should be actually welding transformers.

Question { Polycab, 13304 }

what is the purpose of using 3-point starter in dc machines?

Answer

The purpose of using a 3-point dc starter in a dc machine
is to limit the starting current in the dc circuit.The
starter acts as a resistence in series with the dc circuit
to limit the starting current to the circuit at the
begining & thus acts as a initial protection between dc
rectifier and dc circuit.