摘要:
An ICPT system has a single phase power supply which energises a conductive path (13) and has an inverter (5) to provide an alternating current at an operating frequency greater than the single phase utility supply frequency in the conductive path. The inverter modulates the amplitude of the alternating current with respect to the utility supply frequency such that the amplitude of the alternating current varies. The pick-up has an energy storage element (26) to provide a continuous supply of power to a load (27) irrespective of the varying amplitude of the alternating current in the conductive path.
摘要:
Disclosed is inductive coupling of power to devices having negative resistances, such as gas-filled discharge lamps (fluorescent tubes, neon signs, and the like) from a primary inductive loop, using resonant conditioning of the power provided to the device. A “C” shaped inductor (202) around the loop and a resonating capacitor (406) in parallel with the inductor provide a current source to the lamp (403) from across the capacitor. The circuit is capable of first igniting a lamp using a higher voltage available when the Q of the unloaded circuit is high, then running the lamp or other device at a controlled current. The lamp current is substantially proportional to the primary inductive loop flux, and substantially independent of the lamp resistance. A second inductor (404) in series with the first though not itself a collector of flux acts as a current limit. Applications include lighting, displays (optionally isolated and dimmable), and production of ultraviolet radiation.
摘要:
A pick-up circuit for an inductive power transfer (IPT) system includes a series-tuned pick-up coil and a plurality of parallel AC processing circuits provided between the series-tuned pick-up coil and an output, each processing circuit being adapted to produce an output signal based directly or indirectly at least in part on a voltage of the series-tuned pick-up coil and including a switch for selectively coupling the processing circuit to the output so as to selectively provide the respective output signal to the output of the pick-up circuit.
摘要:
An IPT pick-up circuit includes a resonant circuit including a pick-up inductor and a tuning capacitance in parallel with the pick-up inductor, a control system to control power transfer to the pick-up circuit and a power conditioning impedance provided in series between the resonant circuit and the control system, selected to provide a required power factor in the resonant circuit.
摘要:
Apparatus for providing effective amounts of high-frequency AC power to a long primary trackway (1102), used for inductive power transfer includes transconductance-pi filters (1105) for deliberate mismatching; resulting in independence of current flow and track impedance. These cause the source (1101) to appear as a voltage source and the trackway to appear as a low reactance. Shorting the output (1106) cuts the connected trackway from power without harm. The filter can cause a voltage step-up so driving a longer track. Track termination apparatus is disclosed that acts as a short circuit at only the operating frequency while terminating the track at its characteristic impedance otherwise. Half-bridge and full-bridge power supplies (1101) are described for providing effective amounts of high-frequency AC power to a long primary trackway used for inductive power transfer.
摘要:
Loosely coupled inductive power for charging batteries is rectified from a first power pickup winding and the resulting current source is connected to a battery unit. Each current source is controlled by shorting a second resonant winding. Battery banks may be charged using multiple isolated position-tolerant pickups independently controlled according to the condition of the connected battery unit and by overall commands communicated over an isolated link. The battery unit may be a single cell. In a self-stabilizing bank or monoblock a primary inductive conductor is energized using all the cells, individual cells are separately monitored by control means and any below-average cell can be individually charged from the inductive conductor, thus correcting between-cell variations. The charge in all cells within a bank can be held within 30% to 70% of full charge and prevented from drifting towards full or empty during repetitive charge and discharge times.
摘要:
A circuit (700) for an electric fence energizer (examples are 6 or 24 Joule versions) which synthesizes a pulse having a raised cosine waveform at a first or bus voltage uses a ferrite-cored output transformer (701) to multiply the voltage of the pulse to the required level. A raised cosine waveform has a low harmonic content and little filtering of high-power pulses is required in order to minimize electromagnetic emissions. On closure of a switch (707) in series with an inductor (705) a first capacitor bank (703) commences charging a second smaller capacitor bank (704) in parallel with the output primary and after the peak of the pulse any remaining charge is dissipated in a resistor (708) with the aid of a saturable inductor (702), acting as a switch. The saturable inductor may be the output transformer itself for lower output energizers. The output exhibits little or any reversal of polarity when matched to its load. The circuit may also be useful for applications such as strobe flashers in aircraft.
摘要:
An Inductive Power Transfer System pickup provides a controlled AC power supply by controlled variation of the phase angle between the pickup coil induced voltage (jwMI) and the tuning capacitor C voltage. The phase angle can be varied by maintaining the tuning capacitor C voltage substantially constant for a selected time period. Switches S1 and S2 may be used to clamp the tuning capacitor C voltage at substantially zero volts during the selected time period. Switch S1 can be operated to prevent a rise in positive voltage across the tuning capacitor, and switch S2 can be used to prevent the voltage across the tuning capacitor from going negative.
摘要:
An inductive power transfer (IPT) pick-up circuit has a full-wave rectifier (D1-D4) coupled to a resonant circuit (L1 C1) and adapted to rectify an AC current received from the resonant circuit. A pair of inductors (L2 L3) are provided, being arranged to couple the rectifier to an output (VLoad) of the pick-up circuit and alternately store and release energy to the output.
摘要:
An IPT pick-up circuit includes a resonant circuit including a pick-up inductor and a tuning capacitance in parallel with the pick-up inductor, a control system to control power transfer to the pick-up circuit and a power conditioning impedance provided in series between the resonant circuit and the control system, selected to provide a required power factor in the resonant circuit.