An inductively coupled power transfer receiver including: a. a tunable circuit including: i. a parallel combination (24, 30, 31, 32) of a power receiving coil; and a first variable impedance (30, 31, 32) the first variable impedance (30, 31, 32) configured to tune the power receiving coil, wherein the first variable impedance (30, 31, 32) includes: 1. at least one reactive element; and 2. one or more semiconductor devices for controlling the effective impedance of the at least one reactive element thereby varying the impedance of the first variable inpedance (30, 31, 32); wherein the first variable impedance (30, 31, 32) comprises a second capacitance, the second capacitance is connected in series with a first of the one or more semiconductor devices, and wherein the first of the one or more semiconductor devices operates in linear mode; and ii. a first capacitance connected in series with the parallel combination (24, 30, 31, 32); and b. a power supply circuit which regulates power supplied to an output of the power supply circuit by controlling the operation of the one or more semiconductor devices. a. a tunable circuit including: i. a parallel combination (24, 30, 31, 32) of a power receiving coil; and a first variable impedance (30, 31, 32) the first variable impedance (30, 31, 32) configured to tune the power receiving coil, wherein the first variable impedance (30, 31, 32) includes: 1. at least one reactive element; and 2. one or more semiconductor devices for controlling the effective impedance of the at least one reactive element thereby varying the impedance of the first variable inpedance (30, 31, 32); wherein the first variable impedance (30, 31, 32) comprises a second capacitance, the second capacitance is connected in series with a first of the one or more semiconductor devices, and wherein the first of the one or more semiconductor devices operates in linear mode; and ii. a first capacitance connected in series with the parallel combination (24, 30, 31, 32); and i. a parallel combination (24, 30, 31, 32) of a power receiving coil; and a first variable impedance (30, 31, 32) the first variable impedance (30, 31, 32) configured to tune the power receiving coil, wherein the first variable impedance (30, 31, 32) includes: 1. at least one reactive element; and 2. one or more semiconductor devices for controlling the effective impedance of the at least one reactive element thereby varying the impedance of the first variable inpedance (30, 31, 32); wherein the first variable impedance (30, 31, 32) comprises a second capacitance, the second capacitance is connected in series with a first of the one or more semiconductor devices, and wherein the first of the one or more semiconductor devices operates in linear mode; and 1. at least one reactive element; and 2. one or more semiconductor devices for controlling the effective impedance of the at least one reactive element thereby varying the impedance of the first variable inpedance (30, 31, 32); wherein the first variable impedance (30, 31, 32) comprises a second capacitance, the second capacitance is connected in series with a first of the one or more semiconductor devices, and wherein the first of the one or more semiconductor devices operates in linear mode; and ii. a first capacitance connected in series with the parallel combination (24, 30, 31, 32); and b. a power supply circuit which regulates power supplied to an output of the power supply circuit by controlling the operation of the one or more semiconductor devices.