INDUCTIVE POWER RECEIVER
An inductive power receiver comprising: a power receiving coil; a power regulation stage, configured to connect in parallel with the power receiving coil, and a tuning capacitance configured to connect in series between the power receiving coil and a rectification stage and/or a load, wherein the power regulator is configured with a short circuit control strategy.
1 . An inductive power receiver comprising:
a power receiving coil;
a power regulation stage, configured to connect in parallel with the power receiving coil, and
a tuning capacitance configured to connect in series between the power receiving coil and a rectification stage and/or a load, wherein the power regulator is configured with a short circuit control strategy.
2 . The inductive power receiver in claim 1 wherein the power regulation stage is configured to connect between the coil and the series tuning capacitance.
3 . The inductive power receiver in claim 1 wherein the power regulation stage comprises an AC switch.
4 . The inductive power receiver as claimed in claim 1 wherein the AC switch includes back to back MOSFETs with a common gate and a common source.
5 . The inductive power receiver in claim 2 wherein the AC switch is configured for zero voltage switch on and zero voltage switch off.
6 . The inductive power receiver in claim 1 wherein the series tuning capacitance comprises two capacitors, each configured to connect between the power regulation stage and respective input terminals of a power rectification stage.
7 . The inductive power receiver claim 3 wherein the shunt regulation strategy relates to determining the on time of the AC switch for each cycle at an inductive power transfer signal frequency, based on a load requirement.
8 . The inductive power receiver in claim 1 further comprising a further tuning capacitor configured to connect in parallel with the power receiving coil.
9 . The inductive power receiver in claim 8 wherein the parallel tuning capacitor is configured to provide a resonant frequency for a communications signal, and the series tuning capacitance is configured to provide a resonant frequency for an inductive power transfer signal.
10 . An inductive power receiver comprising:
a power receiving coil and a tuning capacitance forming a resonant circuit;
a rectifier receiving an AC input from the resonant circuit and providing a DC output at its output terminals; and
a power regulation stage, configured to selectively connect the resonant circuit to an output terminal of the rectifier to achieve power flow control.
11 . The inductive power receiver as claimed in claim 10 wherein the power regulation stage is connected directly to a terminal of the power receiving coil.
12 . The inductive power receiver in claim 11 wherein, when switched in, the power regulation stage connects the power receiving coil to a negative output of the rectifier.
13 . The inductive power receiver as claimed in claim 10 wherein the power regulation stage comprises a diode and a semiconductor switch in series.
14 . The inductive power receiver as claimed in claim 10 including a controller which switches the power regulation stage based upon the DC output voltage of the receiver.
15 . The inductive power receiver as claimed in claim 14 wherein the controller switches synchronously with the resonant frequency of the resonant circuit.
16 . The inductive power receiver as claimed in claim 14 wherein the controller is a PID controller.
17 . The inductive power receiver as claimed claim 10 wherein the resonant circuit is a series resonant circuit.
18 . The inductive power receiver as claimed in claim 10 wherein the resonant circuit is a parallel resonant circuit.