摘要:
An uninterruptible power supply (UPS) includes an AC source port configured to connect to an AC power source, a DC source port configured to connect to a DC power source and a load port configured to connect to a load. A rectifier circuit is operative to selectively couple the AC source port to first and second voltage busses through a first inductance. An inverter circuit is operative to selectively couple the load port to the first and second voltage busses through a second inductance. A bidirectional DC source coupling circuit is operative to couple the DC source port to the first and second voltage busses to provide bidirectional power transfer therebetween, preferably such that a voltage at the DC source port is maintained in a substantially fixed proportion to first and second DC voltages at respective ones of the first and second voltage busses. In one embodiment, the bidirectional DC source coupling circuit includes a transformer having first and second inductively coupled windings, the first winding having first and second end taps and a center tap coupled to the neutral bus. A switching circuit is operative to selectively couple the first end tap of the first winding to the first and second voltage busses. A rectifying circuit couples the second end tap of the first winding to the first and second voltage busses. A bidirectional DC-AC converter circuit is coupled between the second winding and the DC source port. Related operating methods are also discussed.
摘要:
A method and apparatus for providing a welding current is disclosed. The power source is capable of receiving any input voltage over a wide range of input voltages and includes an input rectifier that rectifies the ac input into a dc signal. A dc voltage stage converts the dc signal to a desired dc voltage and an inverter inverts the dc signal into a second ac signal. An output transformer receives the second ac signal and provides a third ac signal that has a current magnitude suitable for welding. The welding current may be rectified and smoothed by an output inductor and an output rectifier. A controller provides control signals to the inverter and an auxiliary power controller that can receive a range of input voltages and provide a control power signal to the controller.
摘要:
A method and apparatus for providing a welding current is disclosed. The power source is capable of receiving any input voltage over a wide range of input voltages and includes an input rectifier that rectifies the ac input into a dc signal. A dc voltage stage converts the dc signal to a desired dc voltage and an inverter inverts the dc signal into a second ac signal. An output transformer receives the second ac signal and provides a third ac signal that has a current magnitude suitable for welding. The welding current may be rectified and smoothed by an output inductor and an output rectifier. A controller provides control signals to the inverter and an auxiliary power controller that can receive a range of input voltages and provide a control power signal to the controller.
摘要:
The present invention is based on the discovery of an association between the SNP genotype at the rs12979860 locus in the IL28B gene promoter and the probability of achieving a SVR in HC V-infected patients that are given a triple therapy treatment that contains peginterferon alfa-2a, ribavirin, and a HCV NS5B polymerase inhibitor.