Best Power Technology, Inc.

Bruner Corporation

Pepsico, Inc.

Richard V Baxter

Edward Gerard Beistle

Andrew David Nelson

William J Black

Timothy W Bethuy

Frederick A Stich

Joseph Todd Piatnik

Jeffrey C Thon

David L Layden

Robert W Colburn

James E Ticcioni

Herbert A Podewils

AC line monitoring is provided for uninterruptible power supplies to detect AC power system line faults by comparing the presently received cycle of the AC power line signal with a reference waveform. The reference waveform is formed of a composite of waveforms from prior cycles which adapts over time to the shape of the AC power line waveform, so that waveforms other than pure sinusoids can be accepted without triggering false fault conditions. The composite reference waveform may be formed of essentially all samples from prior cycles with exponentially decaying weighting. An excessive deviation of the current waveform from the reference waveform results in a fault being detected which causes switching of the uninterrupible power supply to provide backup power. The RMS value of the power line voltage is also estimated on a substantially real time basis, preferably by calculating the RMS value of the reference waveform, to provide a fault condition signal when the estimated RMS value falls below a selected level, which also can be utilized to cause switching of the uninterruptible power supply.

Method and apparatus for line power monitoring for uninterruptible power

The inverter of an uninterruptible power system is tested by turning on switches in the inverter at a selected test phase in each half-cycle of the AC input waveform so that the inverter provides a voltage which opposes the AC input voltage waveform during part of each half-cycle of the waveform. The resulting current drawn from the inverter battery, if any, is measured and its peak may be found. The peak battery current during each half-cycle is compared to maximum allowable peak currents to determine if an inverter failure has occurred. If the peak currents are lower than a maximum acceptable value, the test is repeated on a subsequent AC input waveform at a decreased test phase (a shorter time delay from the zero crossing of each half-cycle of the waveform) until the peak current in the first half-cycle is at a selected value, at which time the peak in the second half-cycle is checked to determine if it is within an acceptable range. If not, an inverter test failure is indicated. Inverter test failure is also indicated if repeated cycles during which the test phase is reduced fail to cause the first peak to reach the proper value and the test phase is finally reduced to a minimum allowable test phase. If the inverter has been tested and is found to be operating properly, a battery test can be conducted by selectively disconnecting the AC power system from the load, turning on the inverter for a selected period of time, and detrmining remaining available run time based on the battery voltage while the inverter was running.

Inverter and battery testing for uninterruptible power systems

The Electronic Programmable Water Treatment Controller provides an integrated initiator and sequencer for controlling regeneration of water softening and filtering systems. The controller initiates the regeneration sequence or, in the alternative, an alarm based on a programmable prediction time total flow through the water treatment device or combinations of the foregoing. The sequence of regeneration is controlled in response to selected parameters programmable by the user for valve actuation and timing. Multiple water treatment systems may be controlled in alternating, parallel, or progressive control schemes through communication between controllers, attached to each system, which employ the present invention.

Electronic programmable water treatment controller

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Neenah, WI, United States of America

Richard V Baxter