- Two bobbins that have opposite magnetic polarities and both coils are wound in the same direction. Both beginnings of each coil are connected to ground and the finish of both coils are positive.
- Two bobbins that have the same magnetic polarity and both coils are wound in an opposite direction. Both beginnings of each coil are connected to ground and the finish of both coils are positive.
WRITTEN ON JUNE 12, 2015, BY