Quality Factor (Q)

Quality factor Q measures how under-damped a resonator is. For a series RL tank approximation, Q ≈ ωL / R. High Q means low relative loss per cycle and a sharper frequency response; low Q means more damping and a broader, flatter response.

01High Q: power and pain

• Helps circulate large reactive currents with less copper loss fraction.
• Improves the figure of merit often discussed with k·Q products in loosely coupled links.
• Makes the system more sensitive to detuning (gap change, metal, temperature drift of L/C).
• Can raise voltage/current stress on capacitors and switches near resonance peaks.

02Practical coil Q

Industrial coils chase high Q with Litz wire, careful stranding, good ferrite, and controlled proximity effect — then deliberately add damping or control bandwidth so the charger remains stable under real docking scatter. Datasheet Q measured on a clean bench is an upper bound, not a guarantee on a steel robot chassis.