Transformer efficiency is the ratio of the output power to the input power. Output power is always lower than the input power due to energy losses. Besides measures put in place to reduce energy losses; including use of laminations, soft iron core and copper wires. Commercially used transformers are still about ninety percent efficient, the main cause being the reverse magnetic flux. Magnetic flux is the number of magnetic field lines that pass through a surface. In practice, when the secondary coil is connected to the load it sets up magnetic flux which is in opposition to the input magnetic flux. This forces the primary coil to use more power to counter the reverse magnetic flux. Thus the efficiency of a normal transformer cannot be a hundred percent efficient.

Over a hundred percent transformer design overcomes this effect of reverse magnetic flux by

1. Having a single primary coil in between two secondary coils.
2. Air-gap in the center of the primary coil.
3. The width of the primary coil is twice that of a single secondary coil.
4. The ratio of primary coil to the secondary coils is one to one (1:1:1) hence thicker copper wires (lower resistance) can be used for primary coil since the width is twice that of a secondary coil.

When the secondary coils are on-load, the reverse magnetic flux cannot pass through the primary coil because of:

1. The air-gap which provides a very high resistance to to the two -reverse flux,
2. Because the primary coil is in control of the air-gap.

Thus the two secondary coils cannot load-down primary coil. Since the ratio of the primary coil to secondary coils is one to one (1:1:1), the two secondary coils can be connected in parallel because they have the same volt-ampere rating. An input of 12 volts 1 ampere(12v1A) can therefore produce an output of 12 volts 2 amperes (12v2A), hence the power doubles. Double coiling the secondary coils can boost the efficiency further beyond a hundred percent.

Air-gapped primary coil transformer can lead into the development of automatic generators with battery auto interchange charge systems, which can propel fully electrification of automotive/transport industry. Air-gapped primary coil transformer can also reduce power consumption of devices like Tv’s, Radio’s and iron boxes. Industrial power consumption can also be greatly reduced hence maximizing profits.

Production of air-gapped primary coil transformer is much easier since it uses only the E-laminations as compared to the normal transformer which uses E-I laminations. Assembly process is also easier and faster.