Abstract: An AC-to-AC converter includes input terminals for connection to an AC source, output terminals for connection to a load, a transformer having a primary winding and a secondary winding, a primary-side switch, a pair of secondary-side switches, and a control circuit to control the switches. Closing the primary-side switch causes a primary current to be drawn from the AC source and through the primary winding to store energy in the transformer. Closing one of the secondary-side switches causes a secondary current to be output at the output terminals to transfer energy from the transformer to the load. The secondary current has the same polarity as the primary current when a first of the secondary-side switches is closed, and the opposite polarity when a second of the secondary-side switches is closed. The control circuit is operable to control the switches such that an alternating current is output at the output terminals.

Abstract: A hair styling appliance is described having electrodes and a drive unit. The drive unit is operable to determine a presence of hair between the electrodes. In response to determining that hair is present, the drive unit applies an alternating voltage to the electrodes to heat the hair dielectrically.

Abstract: A haircare device includes at least one power semiconductor switch coupled to drive, in use, a heater. A temperature sensor disposed for sensing a temperature of the at least one power semiconductor switch and outputting a temperature signal indicative of the sensed temperature. A controller is configured to determine whether the temperature signal is indicative of a temperature of the one or more power semiconductor switch exceeding a threshold. When the temperature signal is indicative of the temperature of the one or more power semiconductor switch exceeding the threshold, a power output of the at least one power semiconductor switch is turned off or reduced.

Abstract: A battery charger comprising input terminals for connection to an AC source, output terminals for connection to a battery to be charged, and a power factor correction (PFC) circuit connected between the input terminals and the output terminals. The PFC circuit comprises a current control loop for regulating an input current drawn from the AC source. The voltage at the output of the PFC circuit is regulated by the voltage of the battery which is reflected back to the PFC circuit. As a result, the battery charger acts as a current source that outputs an output current at the output terminals, and the waveform of the output current is periodic with a frequency twice that of the input current and a ripple of at least 50%.

Abstract: A battery charger comprising input terminals for connection to an AC source supplying an alternating input voltage, output terminals for connection to a battery to be charged, and a power factor correction (PFC) circuit connected between the input terminals and the output terminals. The battery charger monitors the voltage of the battery and operates in a first mode when the voltage is below a threshold. The battery charger then switches to a second mode when the voltage exceeds the threshold. The PFC circuit regulates an input current drawn from the AC source such that the waveform of the input current when operating in the first mode is different to that when operating in the second mode.

Abstract: A battery charger comprising input terminals for connection to an AC source supplying an alternating input voltage, output terminals for connection to a battery to be charged, and a PFC circuit connected between the input terminals and the output terminals. The power factor correction (PFC) circuit regulates an input current drawn from the AC source such that the input current has a waveform selected from a sine wave with third harmonic injection, a clipped sine wave and a trapezoidal wave. The battery charger then generates an output current at the output terminals, the output current having a waveform defined by the multiplication of the input current and the input voltage.

Abstract: A capacitor bank comprising at least two series chains each comprising a plurality of capacitors, wherein the series chains are coupled in parallel at corresponding points; and a fusible link arranged to form at least part of each coupling; wherein the corresponding points of each chain that are coupled to one another are at the same voltage when the capacitor bank is operational.

Abstract: The present disclosure relates to a power conversion system comprising a transformer comprising first, second, and third inductive coupling elements, a first power supply arranged to provide a voltage across the first coupling element, a second power supply arranged to provide a voltage across the second coupling element, an output arranged to receive a voltage from the third coupling element. In use, the voltage across the first coupling element and the voltage across the second coupling element are arranged to induce a voltage in the third coupling element. The system also comprises a control arrangement arranged to independently control the operation of the first and second power supplies.

Abstract: A rectifier circuit comprising an AC input, at least one thyristor coupled to the AC input, a DC bus driven by the at least one thyristor, a controller arranged to: derive a first current in the DC bus, derive a maximum current demand on the DC bus, and provide a trigger signal to the at least one thyristor based on the derived maximum current and the derived first current.

Abstract: A rectifier circuit comprising an AC input, at least one thyristor coupled to the AC input, a DC bus driven by the at least one thyristor, a controller arranged to: derive a first current in the DC bus, derive a maximum current demand on the DC bus, and provide a trigger signal to the at least one thyristor based on the derived maximum current and the derived first current.

Abstract: A capacitor bank comprising at least two series chains each comprising a plurality of capacitors, wherein the series chains are coupled in parallel at corresponding points; and a fusible link arranged to form at least part of each coupling; wherein the corresponding points of each chain that are coupled to one another are at the same voltage when the capacitor bank is operational.

Abstract: The present disclosure relates to a power conversion system comprising a transformer comprising first, second, and third inductive coupling elements, a first power supply arranged to provide a voltage across the first coupling element, a second power supply arranged to provide a voltage across the second coupling element, an output arranged to receive a voltage from the third coupling element. In use, the voltage across the first coupling element and the voltage across the second coupling element are arranged to induce a voltage in the third coupling element. The system also comprises a control arrangement arranged to independently control the operation of the first and second power supplies.

Abstract: The present invention provides a suspension vehicle and suspension formulations deliverable from an implantable delivery device. In particular, the suspension vehicle of the present invention allows the formulation of beneficial agent suspensions that are stable over time at ambient and physiological temperatures. In addition, the beneficial agent suspensions formed using the suspension vehicle of the present invention allow controlled delivery of beneficial agent from an implanted delivery device over sustained periods of time, even when such delivery occurs at low flow rates, through a small-diameter delivery channel. Also included in the present invention are implantable delivery devices.

Abstract: Formulations and methods are provided for improving the stability upon exposure to aqueous media of polypeptides present in non-aqueous suspension vehicles. In particular aspects of the invention, formulations are provided that comprise a complex of a metal ion and a polypeptide suspended in a non-aqueous, biocompatible suspension vehicle. Aggregation of individual polypeptide molecules is reduced when aqueous media is introduced to such formulations, serving to stabilize the polypeptide.

Abstract: Liquid polyoxaester polymer materials are provided as suspending vehicles suitable for dispensing of pharmaceutically active agents, such as proteins, from delivery devices, for example, pump-driven dosage forms. Polyoxaesters are made from at least one diacid and at least one diol. Through the use of polyoxaesters virtually solvent-free pharmaceutical suspensions can be created.

Abstract: Suspending vehicles and pharmaceutical suspensions that include a biocompatible polymer that can be combined with a hydrophobic solvent and a hydrophilic solvent to provide vehicles and suspensions that are substantially free of stiff gels upon contact with an aqueous medium are provided. Vehicles and suspensions remain flowable out of a pump-driven dosage form over the life of the dosage form. Such vehicles and suspensions are also biocompatible, suitable for creating and maintaining drug suspensions, and capable of providing stable drug formulations.