A subsea direct electric heating system has a subsea pipeline which has an electrically conducting pipeline material, and a first piggyback cable extending along a portion of the subsea pipeline, electrically connected in series with the subsea pipeline. The system further comprises a topside AC power supply and a power feeder cable which extends from the topside AC power supply to a subsea location. The power feeder cable feeds electric power to the first piggyback cable and the pipeline, resulting in a heating of the pipeline. In order to improve power conditions in the system, the arrangement for reducing the reactive component of the power comprises the power feeder cable, the power feeder cable having a distributed capacitance which is sufficient, in the absence of a capacitor, to result in a power factor of an electric circuit comprising the power feeder cable, the subsea pipeline and the piggyback cable in the range 0.9 to 1.0.

In methods, apparatus, systems, and articles of manufacture to a high efficient hybrid power converter, an example apparatus includes: a switched capacitor (SC) converter to generate a first voltage based on a voltage source; and a direct current-to-direct current (DC-DC) converter to generate a second voltage based on the voltage source of the apparatus, the difference between the first voltage and the second voltage corresponding to an output voltage.

Provided is a Precision Voltage Reference (PVR). In one example, the PVR includes a resonator having an oscillation frequency, the resonator including a first proof-mass, a first forcer located adjacent a first side of the first proof-mass, and a second forcer located adjacent a second side of the first proof-mass. The PVR may include control circuitry configured to generate a reference voltage based on the oscillation frequency of the resonator, at least one converter configured to receive the reference voltage from the control circuitry, provide a first bias voltage to the first forcer based on the reference voltage, provide a second bias voltage to the second forcer based on the reference voltage, and periodically alter a polarity of the first and second bias voltages to drive the oscillation frequency to match a reference frequency, and an output configured to provide the reference voltage as a voltage reference signal.

Provided is a Precision Voltage Reference (PVR). In one example, the PVR includes a resonator having an oscillation frequency, the resonator including a first proof-mass, a first forcer located adjacent a first side of the first proof-mass, and a second forcer located adjacent a second side of the first proof-mass. The PVR may include control circuitry configured to generate a reference voltage based on the oscillation frequency of the resonator, at least one converter configured to receive the reference voltage from the control circuitry, provide a first bias voltage to the first forcer based on the reference voltage, provide a second bias voltage to the second forcer based on the reference voltage, and periodically alter a polarity of the first and second bias voltages to drive the oscillation frequency to match a reference frequency, and an output configured to provide the reference voltage as a voltage reference signal.

An electrical system including a body having a structure resembling a double helix having twisted conductive wires wound around both helical structures may be used to produce useful electromagnetic effects for various applications, including providing therapy and promoting growth of living organisms.

An electrical system including a body having a structure resembling a double helix having twisted conductive wires wound around both helical structures may be used to produce useful electromagnetic effects for various applications, including providing therapy and promoting growth of living organisms.

An energy harvester system includes an aircraft power cable carrying an alternating current and an energy harvester. The energy harvester includes a ferromagnetic ring encircling the aircraft power cable and configured so that the alternating current in the aircraft power cable generates magnetic flux in the ferromagnetic ring and an inductive coil wrapped around at least a portion of the ferromagnetic ring to generate a voltage from the magnetic flux in the ferromagnetic ring.

An energy harvester system includes an aircraft power cable carrying an alternating current and an energy harvester. The energy harvester includes a ferromagnetic ring encircling the aircraft power cable and configured so that the alternating current in the aircraft power cable generates magnetic flux in the ferromagnetic ring and an inductive coil wrapped around at least a portion of the ferromagnetic ring to generate a voltage from the magnetic flux in the ferromagnetic ring.

According to various embodiments, an intelligent electronic device IED, such as a protective relay, includes a universal binary input circuit for receiving an AC or DC binary input with a voltage magnitude between approximately 0 Volts and 300 Volts. The universal binary input provides reinforced isolation via an input protection subcircuit and an optocoupler for communicating an optical signal with an electrically isolated controller based on the received binary input signal. In one embodiment, a duty cycle modulation subcircuit generates a pulse width modulated drive signal to drive the optocoupler based on the voltage magnitude of the received binary input. The duty cycle of the pulse width modulated drive signal is (linearly or nonlinearly) inversely proportional to the voltage magnitude of the received binary input.

According to various embodiments, an intelligent electronic device IED, such as a protective relay, includes a universal binary input circuit for receiving an AC or DC binary input with a voltage magnitude between approximately 0 Volts and 300 Volts. The universal binary input provides reinforced isolation via an input protection subcircuit and an optocoupler for communicating an optical signal with an electrically isolated controller based on the received binary input signal. In one embodiment, a duty cycle modulation subcircuit generates a pulse width modulated drive signal to drive the optocoupler based on the voltage magnitude of the received binary input. The duty cycle of the pulse width modulated drive signal is (linearly or nonlinearly) inversely proportional to the voltage magnitude of the received binary input.