R-core is unique type of core designed and developed by
Japanese engineers. These cores are manufactured in the conventional
rectangular shape but the slitting is done by a special process,
ensuring high stacking factor. The special heat treatment, continuous
strip and no gap ensure higher efficiency to the transformers.
The cores are manufactured using M4 & M2H grade
material of 0.23 / 0.27 mm thickness and available in various standard
R-core Transformers are manufactured using the unique
rectangular core with round cross section known as R-core. The special
feature of this transformer is that the core is gap less and
continuous. The winding is done on special round bobbins on two
parallel legs of the core. In comparison with EI Transformers of same
capacity, the R-core transformer is COMPACT (nearly 40% smaller) and
has a LOW TEMPERATURE ELEVATION.
Further the LEAKAGE FLUX of the transformer IS VERY LOW
(about 1/10th of conventional transformers), which permits the
equipment manufacturer to place the transformer close to critical
electronic components. The balanced winding & low leakage flux
ensures LOW NOISE of the transformers. This gives a cutting edge to the
transformer for use in test equipment, audio & video amplifiers
& other noise sensitive equipment.
The other unique feature is the use of Bobbins in two
parts. The primary winding and secondary winding are done on separate
bobbins thus ensuring complete isolation between the two windings. This
allows meeting of any safety standards requirement.
The R-core Transformers have found wide application in
CRT display units, Audio equipments, Satellite receivers, Printers,
Photo-copier machines, weighing scales and many more.
special characteristic of the R-core transformer is the ability of the
two coils to mutually cancel each other's magnetic flux by means of
balanced, symmetrical winding of the coils. With this winding method
the leakage flux can be kept to a minimum amount. The key point is the
exact balance of the two coils.
2. The R-core transformer has absolutely no gap in its
magnetic paths. On the other hand, the EI-type has a magnetic gap in 6
locations, and the CI or the cut core type has 2 to 4 magnetic gaps. A
great deal of leakage flux escapes from these magnetic gaps.
3. The R-core transformer makes a maximum use of the
superior material properties of the Z-H grain-oriented silicon steel.
As a result, the core's magnetic resistance is very low, and the cross
section of the magnetic path is uniform. The exciting current of the
R-core transformer is lower than the EI-type ensuring that the leakage
flux is minimal and a higher percentage of the entire magnetic flux of
the R-core transformer is being put to much more effective use.
View R-Core dimensions
and important parameter comparisons
with different types of transformers.