Titanium coils usually refers to a circular coil wire winding, the most common application: motor, inductance, transformer and a loop antenna etc.  A coil circuit is an inductor. Is the guiding line of a winding up each other, wire insulation, and insulation pipe can be hollow, can also contain iron or magnetic core inductance, referred to as. Inductor and inductance can be divided into fixed and variable inductance, inductance coil inductance coil or as fixed.