Abstract: Measurement system which can be used at patients bedside to monitor the amount of blood drawn from the patient. The system uses disposable sensor and electronics to measure accurately and in real time the volume of the blood drawn from the patient using a paddlewheel sensor wherein the rotation of the paddle wheel is correlated with the volume of the blood that is drawn from the patient and collected.

Abstract: A method for detecting the presence of a receiver in an inductively coupled power transfer system having a transmitter and receiver. The method includes switching on a transmitter converter at a first frequency, measuring the inrush current and determining whether there is a receiver present. In another method, the inrush current is measured for a range of transmitter frequencies, and the variation in current is used to determine where there is a receiver present. In another method, the inrush current is measured when there is a change in voltage in the transmitter, and the variation in current is used to determine where there is a receiver present. In another method, the current supplied to the transmitter converter is measured over two transmitter frequencies, and the variation in current is used to determine where there is a receiver present.

Abstract: A powered joint having a first joint component and second joint component in which the first joint component has multiple degrees of rotational freedom with respect to the second joint component, the powered joint including one or more power transmission coils associated with the first component; a plurality of power receiving coils associated with the second component; a sensor which determines the orientation of the second component with respect to the first component; and a control circuit for selectively connecting one of the plurality of power receiving coils to a power receiving circuit based on information received from the sensor.

Abstract: An inductive power transfer system (IPT) pick-up comprises: a pick-up coil capable of generating a voltage by magnetic induction from a primary conductive pathway, and a tuning capacitor associated with the pick-up coil to provide a first pick-up resonant circuit; a first output associated with a first control means to substantially control the voltage or current provided by the first output; a further resonant circuit connected in series or parallel with the first pick-up resonant circuit; and a second output associated with a second control means to control the voltage or current provided by the second output and a method of providing an additional independently controllable output from an IPT pick-up having a resonant pick-up circuit is also disclosed.

Abstract: A method for detecting the presence of a receiver in an inductively coupled power transfer system having a transmitter and receiver. The method includes switching on a transmitter converter at a first frequency, measuring the inrush current and determining whether there is a receiver present. In another method, the inrush current is measured for a range of transmitter frequencies, and the variation in current is used to determine where there is a receiver present. In another method, the inrush current is measured when there is a change in voltage in the transmitter, and the variation in current is used to determine where there is a receiver present. In another method, the current supplied to the transmitter converter is measured over two transmitter frequencies, and the variation in current is used to determine where there is a receiver present.

Abstract: A method for detecting the presence of a receiver in an inductively coupled power transfer system having a transmitter and receiver. The method includes switching on a transmitter converter at a first frequency, measuring the inrush current and determining whether there is a receiver present. In another method, the inrush current is measured for a range of transmitter frequencies, and the variation in current is used to determine where there is a receiver present. In another method, the inrush current is measured when there is a change in voltage in the transmitter, and the variation in current is used to determine where there is a receiver present. In another method, the current supplied to the transmitter converter is measured over two transmitter frequencies, and the variation in current is used to determine where there is a receiver present.

Abstract: A powered joint having a first joint component and second joint component in which the first joint component has multiple degrees of rotational freedom with respect to the second joint component, the powered joint including one or more power transmission coils associated with the first component; a plurality of power receiving coils associated with the second component; a sensor which determines the orientation of the second component with respect to the first component; and a control circuit for selectively connecting one of the plurality of power receiving coils to a power receiving circuit based on information received from the sensor.

Abstract: A method for controlling a converter including a resonant circuit, where the converter is controlled such that control switches are switched into a first state at the occurrence of an event that is related to a dependent variable of the converter and are switched into a second state at the occurrence of an event that is not related to a dependent variable of the converter, and the method may be employed in a converter or an inductive power transfer transmitter.

Abstract: An inductive power transfer device including: a resonant circuit, having a power transfer coil and a power transfer capacitor; a coupling coil, magnetically-coupled to the power transfer coil; a variable impedance; and a controller configured to determine the impedance value of the variable impedance based on predetermined criteria including: substantially regulating power provided to a load; tuning the resonant circuit resonant frequency substantially to a predetermined frequency; adjusting a frequency of a magnetic field associated with the power transfer coil; and/or adjusting an impedance reflected by the power transfer coil to a corresponding coupled power transfer coil.

Abstract: An inductive power transfer (IPT) pick-up circuit for receiving power from a primary conductor has a pick-up coil (L2) and a compensation capacitor (C2) so that the pick-up coil (L2) may be resonant at the system operating frequency a switch (S1, S2), and a plurality of reactive elements (L3, C3) whereby when the switch is in one of an on state or an off state the additional reactive elements (L3, C3) are resonant at the operating frequency to reduce power being supplied to an output of the pick-up circuit.

Abstract: A method for detecting the presence of a receiver in an inductively coupled power transfer system having a transmitter and receiver. The method includes switching on a transmitter converter at a first frequency, measuring the inrush current and determining whether there is a receiver present. In another method, the inrush current is measured for a range of transmitter frequencies, and the variation in current is used to determine where there is a receiver present. In another method, the inrush current is measured when there is a change in voltage in the transmitter, and the variation in current is used to determine where there is a receiver present. In another method, the current supplied to the transmitter converter is measured over two transmitter frequencies, and the variation in current is used to determine where there is a receiver present.

Abstract: A method for controlling a converter including a resonant circuit, where the converter is controlled such that control switches are switched into a first state at the occurrence of an event that is related to a dependent variable of the converter and are switched into a second state at the occurrence of an event that is not related to a dependent variable of the converter. The method may be employed in a converter or an inductive power transfer transmitter.

Abstract: A method for detecting the presence of a receiver in an inductively coupled power transfer system having a transmitter and receiver. The method includes switching on a transmitter converter at a first frequency, measuring the inrush current and determining whether there is a receiver present. In another method, the inrush current is measured for a range of transmitter frequencies, and the variation in current is used to determine where there is a receiver present. In another method, the inrush current is measured when there is a change in voltage in the transmitter, and the variation in current is used to determine where there is a receiver present. In another method, the current supplied to the transmitter converter is measured over two transmitter frequencies, and the variation in current is used to determine where there is a receiver present.

Abstract: An inductive power transfer (IPT) pick-up circuit for receiving power from a primary conductor has a pick-up coil (L2) and a compensation capacitor (C2) so that the pick-up coil (L2) may be resonant at the system operating frequency a switch (S1, S2), and a plurality of reactive elements (L3, C3) whereby when the switch is in one of an on state or an off state the additional reactive elements (L3, C3) are resonant at the operating frequency to reduce power being supplied to an output of the pick-up circuit.

Abstract: A method for controlling a converter including a resonant circuit, where the converter is controlled such that control switches are switched into a first state at the occurrence of an event that is related to a dependent variable of the converter and are switched into a second state at the occurrence of an event that is not related to a dependent variable of the converter. The method may be employed in a converter or an inductive power transfer transmitter.

Abstract: An inductive power transfer device including: a resonant circuit, having a power transfer coil and a power transfer capacitor; a coupling coil, magnetically-coupled to the power transfer coil; a variable impedance; and a controller configured to determine the impedance value of the variable impedance based on predetermined criteria including: substantially regulating power provided to a load; tuning the resonant circuit resonant frequency substantially to a predetermined frequency; adjusting a frequency of a magnetic field associated with the power transfer coil; and/or adjusting an impedance reflected by the power transfer coil to a corresponding coupled power transfer coil.

Abstract: A method for detecting the presence of a receiver in an inductively coupled power transfer system having a transmitter and receiver. The method includes switching on a transmitter converter at a first frequency, measuring the inrush current and determining whether there is a receiver present. In another method, the inrush current is measured for a range of transmitter frequencies, and the variation in current is used to determine where there is a receiver present. In another method, the inrush current is measured when there is a change in voltage in the transmitter, and the variation in current is used to determine where there is a receiver present. In another method, the current supplied to the transmitter converter is measured over two transmitter frequencies, and the variation in current is used to determine where there is a receiver present.

Abstract: A method for controlling a converter including a resonant circuit, where the converter is controlled such that control switches are switched into a first state at the occurrence of an event that is related to a dependent variable of the converter and are switched into a second state at the occurrence of an event that is not related to a dependent variable of the converter. The method may be employed in a converter or an inductive power transfer transmitter.

Abstract: An inductive power transfer system (IPT) pick-up comprises: a pick-up coil capable of generating a voltage by magnetic induction from a primary conductive pathway, and a tuning capacitor associated with the pick-up coil to provide a first pick-up resonant circuit; a first output associated with a first control means to substantially control the voltage or current provided by the first output; a further resonant circuit connected in series or parallel with the first pick-up resonant circuit; and a second output associated with a second control means to control the voltage or current provided by the second output. A method of providing an additional independently controllable output from an IPT pick-up having a resonant pick-up circuit is also disclosed.

Abstract: An inductive power transfer (IPT) pick-up circuit for receiving power from a primary conductor has a pick-up coil (L2) and a compensation capacitor (C2) so that the pick-up coil (L2) may be resonant at the system operating frequency a switch (S1, S2), and a plurality of reactive elements (L3, C3) whereby when the switch is in one of an on state or an off state the additional reactive elements (L3, C3) are resonant at the operating frequency to reduce power being supplied to an output of the pick-up circuit.