Azo Sensors has published 'An Introduction to a 3-Axis Transmitter Coil'. Click the link below to view the full article. 

TT Electronics is helping the science-fiction concept of virtual or augmented reality to become everyday reality. The idea is simple; smart software and hardware are combined either to modify the world you see or place you into a totally virtual one.


A lot of us have experienced a type of augmented reality by playing Pokémon GO, where a combination of location tracking and software allows you to observe virtual Pokémon in the real world through your smartphone.

To make the illusion work, the software has to know where you are in space – when you move your hands or turn your head. That’s easy for your phone, which has location tracking build in. It’s more of a challenge for the human body, and that is where TT Electronics' 3-axis coil comes in.

Roshan Shrestha, Design Engineer, TT Electronics


3-Axis Coils


3-axis coils generate signals telling software exactly where the coil (and whatever it is fixed to) is located in space by moving in magnetic fields. Each coil works on the same principle as a generator, which creates electricity when a coil moves in a magnetic field. The three signals which are produced as a result correspond to the x, y, and z axes which show a moving point in three-dimensional space.


Tracking Movement in 3D Space


Location tracking consists of two varieties of coil. The 3-axis transmitter coil, for example, placed on a head-mounted display or your finger, sends three signals indicating that its position is altering. The signal from the y-axis coil will demonstrate movement if you move your finger straight up and down, while the x- and z-coils exhibit no change.

Movement in the x- and z-axes would be observed if the finger was moved in a horizontal circle. Found somewhere in the area, the receiver coil receives the three separate signals and transmits them to the software, which produces the image you see on your screen or goggles.


Power Source


Usually, the receiver coil acquires its power from the electrical grid. As they are mobile, the transmitter coils generally require another source of power. The power source is dependent on the signal strength needed to reach and activate the receiver coil.

For example, if a low strength is needed over a very short distance without much electrical interference, you could configure a passive coil. In a passive coil, the voltage generated by moving the coil in the magnetic field is all the power that is required to reach the receiver.

To overcome interference, or over larger distances, transmission power is generated by a battery and the signal is modulated by voltage created in the coil from movement in the magnetic field.




More will be asked of 3-axis coils as the fields of VR and AR grow. Smaller and even more precise coils will be needed. They will be dependent on fine-wire winding, and in the majority of instances they must be tailored to extremely specific needs. This is where TT Electronics excels and is serving this growing market.


Related Stories


About The Author

Welly Chou



Welly Chou is the design engineering manager at TT Electronics. He has 18 years of experience in the magnetics industry. His magnetics background ranges widely from medical miniature coils to transformers and inductors. Welly holds a bachelor's of electrical engineering, minor in mathematics and computer science, and a master's in MBA from Hamline University.