US Patent 7367936 Magnetic stimulators and coils therefor

A magnetic coil inductor for use in magnetic stimulators comprises two face-to-face electrically connected windings each having a multiplicity of turns of a respective conductor. Corresponding turns are separated by a gap which typically is of the order of 18 to 20% of the total height of the coil. The magnetic stimulator includes a discharge capacitor and a switch arrangement operable to provide discharge pulses at a selected repetition rate through the inductor, the inductor and the capacitor constituting a resonant circuit of which the resonant frequency is substantially in excess of the repetition rate and is typically between 2 and 6 kHz.