Laminated transformers, the most common type of transformer, are made
by stacking punched strips of iron or nickel that serve as the core of
the transformer. Laminated transformers are less expensive than both
the R-Core and toroidal construction transformers and can be designed
meet all types of agency approvals (UL, CSA, VDE).
The laminated construction is often used in isolation transformers,
step-up and step-down transformers, autotransformers, power supplies,
and measurement instruments, industrial controls, power transducers,
amplifiers, voice and music reproduction equipment, telephone
networks, and lighting controls.
The gauge (4 mil to 25 mil) and grade (M-55 to M-6) of the laminations
are used to control core loss and exciting current.
Silicon laminations, both grain oriented and
non-oriented steel, as
well as 50% to 80% nickel laminations are used to meet different
Primary and Secondary windings can be constructed as
side by side windings on a 3-flange bobbin, or wound on two separate
to control leakage inductance and winding capacitance.
For high-voltage applications or high breakdown voltage
layer wound laminated transformers are cheaper than toroids and most
Custom Magnetics typically produces laminated
transformers between 1
mW and 2,000 W. The normal frequency range is 25 Hz to 400 Hz for
power applications and 20 Hz to 20,000 Hz for audio applications.
Laminated transformers are available in several shapes including: Long
E, EE, EI, UI, L, and J. Typical sizes range from 1/4" cube to 8"
cube. Many types of standard mounting styles are available.
Laminated transformers can be designed with fly leads, solder lugs, or
printed circuit board pins.