| Schweitzer Engineering Laboratories, Inc. Patent applications |
| Patent application number | Title | Published |
|---|
| 20110260042 | Power Angle Monitor - A system and method for monitoring the rotation of a generator rotor and calculating a power angle using an optical rotor displacement monitor. The monitor uses a light beam directed toward the rotor to detect a marking thereon, and generates an electrical pulse when the marking is detected. The time between the pulse and a reference point (such as a zero crossing) of the signal waveform from the terminals of the generator is used to calculate the power angle of the generator. The system is adaptive in that it can account for new markings on the rotor. The system may be connected to a network so that power angles from various generators on the electrical network may be compared. The system may further be connected to a common time source such that a time stamp may be applied to the power angles from various generators, allowing for more accurate comparison of the power angles. | 10-27-2011 |
| 20090115564 | Systems and Methods for Forming an Isolated Transformer - A transformer to isolate a primary winding from a signal winding include a primary substrate (which may comprise a printed circuit board (PCB)) and a secondary substrate. The primary and secondary substrates may each have three openings to allow first and second E-E core halves to be joined therebetween. A first insulator may be disposed between the primary and secondary substrates to isolate the primary substrate from the secondary substrate. A second insulator may secure the primary and secondary substrates in place and insulate the secondary substrate from the core. The primary and secondary substrates may each include a Faraday shield its outer layers. A shield slit to prevent shorting between the legs of the E-E core may be formed by cutting a channel in the shield between the opening of the primary and secondary substrates. A retaining clip may be used to clamp together the primary substrate, first and second core E-E core halves, secondary substrate and second insulator. A primary winding and sense winding may be disposed within the primary substrate and a signal winding may be disposed within the secondary substrate. The primary, sense, and signal windings may be positioned so that the magnetic flux produced by the primary winding passes through the signal and sense windings in substantially equal proportions. The primary and signal winding may enter the E-E core from opposite directions to choke any common mode current therebetween. | 05-07-2009 |
| 20090115509 | Systems and Methods for Isolating an Analog Signal - An accurate linear equivalent of an analog signal may be produced across an isolation barrier by driving a primary transformer winding with a drive amplifier and compensation amplifier, where the compensation operational amplifier amplifies a difference between a signal produced on a sense winding of the transformer and a combination of the input analog signal and output of the drive amplifier. The system may be stabilized by a lead-lag network between the sense winding, input signal, and operational amplifier. The transformer may comprise an isolation barrier to isolate the input analog signal from a signal winding. The primary winding of the transformer, driven by the operational amplifier and driver amplifier circuit, may produce a linear equivalent of the input analog signal across the isolation barrier on a signal winding of the transformer. The transformer may comprise power supply windings connected to a power supply bridge rectifier and regulator circuit to control and supply power to the circuit components across the isolation barrier. The operational amplifier and drive amplifier circuit may be active for only a portion of each analog signal sampling period. The control signals may provide power during the rest of the sampling cycle. | 05-07-2009 |
