The invention discloses a device for collection of tiny charges in the Nano-Coulomb-range and below, comprising at least one capacitor stack build by n capacitors and 2n switches (nϵN), at least one further capacitor outside the capacitor stack as buffer capacity, at least two additional switches and a DC input source. The n capacitors are dedicated to be sequentially charged by the DC input source one after the other, wherein the 2n switches in the capacitor stack couple the n capacitors sequentially to the DC input source. The at least one further capacitor is dedicated to be charged from the n capacitors of the capacitor stack at once. Furthermore, the invention discloses a method for small charge collection, comprising the steps of sequentially charging the n capacitors of the at least one capacitor stack by coupling one capacitor after the other to the DC input source by selectively closing the switches and discharging the n capacitors of the capacitor stack into at least one further capacitor outside the capacitor stack (nϵN). Additionally, the usage of the device or the method according to the invention to collect charges from sources with electrical potentials of a few millivolts is disclosed.

A cascaded multilevel converter is disclosed. The converter comprises a plurality of modules coupled to form a branch, each of the modules comprising a switching circuit and a DC link for supplying DC voltage to the switching circuit. The converter further comprises a controller for controlling the switching circuit of each module to generate an AC voltage in the branch, wherein the controller is configured to: determine for each module a voltage across a capacitor of the DC link of the module, determine for each module a reference power value for charging the capacitor of the DC link of the module to a reference voltage value for the module, determine, from the reference power values of the modules, a common reference AC current value for AC current in the branch, determine, from the common reference AC current value, a common reference AC voltage value for AC voltage in the branch.

A device includes: a wireless power receiver configured to receive wireless power from an external device external to a body; a capacitor configured to store therein the wireless power received by the wireless power receiver; a wireless transceiver configured to transmit, to the external device, information associated with stored energy of the capacitor and scheduled energy to be used; and a processor configured to operate with the stored energy of the capacitor and process a biosignal of the body, wherein an operation of the external device and an operation of the device are synchronized, and a wireless power quantity of the wireless power to be received by the wireless power receiver from the external device is determined based on the information transmitted from the wireless transceiver to the external device.

A DC-link charging arrangement is described having a DC-link capacitor, rectifier means, and contactor means arranged between supply voltage ports and the rectifier means and having at least one contactor. Such a charging arrangement should enable charging of a DC-link capacitor in a simple way with low losses. To this end a charging capacitor is arranged bridging the at least one contactor.

A surface cleaning apparatus, such as a portable surface cleaning apparatus is powered by one or more ultracapacitors and a charging unit for same is provided.

A method for energy harvesting is provided that uses an auxiliary energy storage device as a voltage source for the controller of a main voltage converter system. The auxiliary energy storage device is initially charged with a cold-start voltage converter and thereafter a main voltage converter system is charging a first rechargeable energy storage device until an upper charging threshold level is reached. The voltage of the auxiliary energy storage device is monitored and kept equal to a target value suitable for operating the controller, or alternatively within a predefined voltage range corresponding to the supply voltage range for the controller. A power management integrated circuit for energy harvesting is provided that includes a cold-start and a main voltage converter system, an internal voltage node is kept at a target value or within a voltage range suitable as a supply voltage for the controller.

In a method for operating an electric vehicle and an electric vehicle, including an electric traction drive device for driving vehicle, a control device for controlling the driving, a first energy storage device, for supplying the control device using a first DC voltage, a second energy storage device, for supplying the traction drive device using a second DC voltage, and an energy supply unit for providing an output DC voltage, the first energy storage device is connected to the second energy storage device via a converter device, the first energy storage device is connected to the energy supply unit, the converter device converts the first DC voltage into the second DC voltage, and a power flow from the second energy storage device to the first energy storage device is prevented.

A wireless device includes an energy harvester and an energy storage that operate in a sequence of energy harvesting cycles to alternately harvest energy and release energy for supplying the wireless device. The wireless device also includes a processing circuit and a wireless communication circuit. A configuration method for the wireless device includes first step where a base station receives a signal from the wireless device indicating wireless communication circuit entry into a receiving operation mode. In a second step, the base station transmits configuration data to the wireless device. The received configuration data is temporarily stored in a memory area of the wireless communication circuit. In a third step, the temporarily stored configuration data is transmitted from the wireless communication circuit to the processing circuit for storage in a memory area. The second and third steps are carried out during distinct energy harvesting cycles of the wireless device.

A data center rack is disclosed. The data center rack comprises a plurality of chamber openings including computing devices; and at least one chamber opening including a mounted ultracapacitor module comprising a plurality of ultracapacitors. A data center comprising a data center rack is also disclosed.

A hybrid supercapacitor where the charging state is indicated by color is demonstrated. The device comprises a molecular network that functions as both the battery-type electrode and the charge indicator. Related batteries, electrodes and devices, their processes of preparation and methods of use are provided as well. Further included in this invention are data-storage devices and catalysts based on multilayers comprising metal-ion organic complexes. This invention further provides methods of preparation of the multilayers, of the data-storage devices, of the catalyst devices and methods of use thereof.