Back to results
US 5,633,789 AGranted
Failure-free power source device
AssigneeNEC Corporation
InventorsTakumi Kimura, Katsunori Akaba, Fumihiko Hiratsuka, Takaaki Sato
Life of this patent
Estimating the term…
Abstract
A failure-free power source device memorizes the history of errors of a commercially available power source, monitors the stability of the power source on the basis of the history, directly outputs, when the power source remains stable for more than a predetermined period of time, an AC input as an AC output, and releases, when an error occurs in the power source, energy stored in an accumulator until a predetermined period of time expires to thereby output it as an AC output via an inverter.
Claims19
A failure-free power source device comprising:
- a rectifier for converting input AC power to first DC power;
- an accumulator for accumulating said first DC power to prepare for a discharge at the time of a power failure, while outputting second DC power;
- an inverter for converting said second DC power to AC power to thereby output an inverter signal;
- power error detecting means for receiving said input AC power and for detecting an error in said input AC power and outputting a power error signal in response to said detection;
- end-of-observation monitoring means, having means for receiving a sequential plurality of said power error signals, for outputting a switching signal in response to a power error signal received subsequent to said sequential plurality, and for terminating said switching signal in response to not receiving a further subsequent power error signal for an observation time duration, said observation time duration based on said received sequential plurality of said power error signals;
- and
- selecting means for outputting, on receiving at least one of said power error signal and said switching signal, said inverter output as an AC output and for outputting, when neither said power error signal nor said switching signal appears, said input AC power as said AC output.
4 more elements
Dependencies are inferred from the claim text.