Multilayer printed circuit board comprising a battery charging circuitry and an induction coil

A circuit board for an electrical device, the circuit board having: at least one coil for receiving a magnetic field from a source remote from the circuit board and generating an alternating electrical field therefrom, the coil being defined by conductive tracks lying on or in the circuit board; and a charging circuit having an input and an output, the input being connected to the coil and the charging circuit being arranged for providing a direct current at the output from the said electrical field generated by the coil.