Patents by Inventor Steven M. Millett
Steven M. Millett has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Patent number: 11897725Abstract: A braking system for an elevator includes an electromagnetic brake operably connected to an elevator car, and a control circuit operably connected to the electromagnetic brake. The control circuit includes a switching mechanism configured to selectively modify a rate of engagement of the electromagnetic brake to selectively modify a rate of deceleration of the elevator car. The switching mechanism has a first position, a second position and a third position, to selectively modify the rate of engagement.Type: GrantFiled: July 10, 2020Date of Patent: February 13, 2024Assignee: OTIS ELEVATOR COMPANYInventors: Steven M. Millett, Ismail Agirman, Amir Lotfi
-
Publication number: 20200339382Abstract: A braking system for an elevator includes an electromagnetic brake operably connected to an elevator car, and a control circuit operably connected to the electromagnetic brake. The control circuit includes a switching mechanism configured to selectively modify a rate of engagement of the electromagnetic brake to selectively modify a rate of deceleration of the elevator car. The switching mechanism has a first position, a second position and a third position, to selectively modify the rate of engagement.Type: ApplicationFiled: July 10, 2020Publication date: October 29, 2020Inventors: Steven M. Millett, Ismail Agirman, Amir Lotfi
-
Patent number: 10734925Abstract: A regenerative drive (30) and method for providing power from such to at least one auxiliary power supply (41, 43) is disclosed. The drive may include a converter (32) and an inverter (34) connected by a DC bus (33), and a controller (54) configured to apply at least one of unipolar modulation and bipolar modulation to the converter (32) and the inverter (34), and to provide about half of the output voltage across the upper portion (130) of the DC bus (33) and about half of the output voltage across the lower portion (136) of the DC bus (33), when the upper and lower portions (130, 136) of the DC bus (33) are unevenly loaded. A first auxiliary power supply (41) may be connected to one of the upper and lower portions (130, 136) of the DC bus (33) and may receive power from the multilevel regenerative drive (30).Type: GrantFiled: December 18, 2013Date of Patent: August 4, 2020Assignee: OTIS ELEVATOR COMPANYInventors: Steven M. Millett, Ismail Agirman
-
Patent number: 10450162Abstract: A brake system for an elevator car includes a multiple of brake segments for deceleration of the elevator car and a brake control circuit operable to control operation of each of the multiple of brake segments to passively sequence activation of each of the multiple of brake segments.Type: GrantFiled: June 27, 2016Date of Patent: October 22, 2019Assignee: Otis Elevator CompanyInventors: Amir Lotfi, YiSug Kwon, Steven M. Millett
-
Patent number: 10246294Abstract: A regenerative elevator drive device, a method for buffering energy of a regenerative elevator drive device, and an elevator system are disclosed. The regenerative elevator drive device may include an inverter having a plurality of power components and a converter having a plurality of power components. The regenerative drive may further include a direct current (DC) link bridging the inverter and the converter, the DC link including a first capacitor bridging the inverter and the converter and a second capacitor in parallel with the first capacitor. The regenerative elevator drive device may be a multi-level regenerative drive device.Type: GrantFiled: December 18, 2013Date of Patent: April 2, 2019Assignee: OTIS ELEVATOR COMPANYInventors: Ismail Agirman, Steven M. Millett, HanJong Kim
-
Patent number: 10008917Abstract: A regenerative drive device and a method for configuring the DC link of a regenerative drive device are disclosed. The multilevel regenerative drive device may include an inverter having a plurality of power components and a converter having a plurality of power components. The multilevel regenerative drive device may also include a direct current (DC) link bridging the inverter and the converter, the DC link including a capacitor, an inverter neutral point, and a converter neutral point independent of the inverter neutral point. Alternatively, the inverter neutral point and the converter neutral point may be connected.Type: GrantFiled: December 18, 2013Date of Patent: June 26, 2018Assignee: OTIS ELEVATOR COMPANYInventors: Ismail Agirman, Steven M. Millett, Shashank Krishnamurthy, Yang Wang
-
Publication number: 20170317607Abstract: A three-level converter includes a first converter leg having first switches connected across a positive DC node and a negative DC node, a second converter leg having second switches connected across the positive DC node and the negative DC node, and a third converter leg having third switches connected across the positive DC node the negative DC node. The converter includes a battery connected between the positive DC node and the negative DC node, and center-connected to a ground node having a ground potential. Each of the first, second, and third converter legs is connected to the ground node.Type: ApplicationFiled: October 21, 2015Publication date: November 2, 2017Inventors: Ismail Agirman, Steven M. Millett, Daryl J. Marvin, Shashank Krishnamurthy
-
Patent number: 9804612Abstract: An exemplary power supply includes a low side switch and a high side switch. A driver controls operation of the high side switch. A bootstrap capacitor supplies power to the driver. An energy storage portion is in parallel with the bootstrap capacitor to provide control over whether a voltage of the bootstrap capacitor drops below a desired voltage. A voltage regulator is in parallel with the bootstrap capacitor for limiting current provided to the bootstrap capacitor and for regulating a voltage of the bootstrap capacitor.Type: GrantFiled: July 30, 2010Date of Patent: October 31, 2017Assignee: OTIS ELEVATOR COMPANYInventors: Daryl J. Marvin, Steven M. Millett
-
Publication number: 20170029242Abstract: A regenerative elevator drive device, a method for buffering energy of a regenerative elevator drive device, and an elevator system are disclosed. The regenerative elevator drive device may include an inverter having a plurality of power components and a converter having a plurality of power components. The regenerative drive may further include a direct current (DC) link bridging the inverter and the converter, the DC link including a first capacitor bridging the inverter and the converter and a second capacitor in parallel with the first capacitor. The regenerative elevator drive device may be a multi-level regenerative drive device.Type: ApplicationFiled: December 18, 2013Publication date: February 2, 2017Applicant: OTIS ELEVATOR COMPANYInventors: Ismail Agirman, Steven M. Millett, HanJong Kim
-
Publication number: 20170008731Abstract: A brake system for an elevator car includes a multiple of brake segments for deceleration of the elevator car and a brake control circuit operable to control operation of each of the multiple of brake segments to passively sequence activation of each of the multiple of brake segments.Type: ApplicationFiled: June 27, 2016Publication date: January 12, 2017Inventors: Amir Lotfi, YiSug Kwon, Steven M. Millett
-
Publication number: 20170005562Abstract: A regenerative drive device and a method for configuring the DC link of a regenerative drive device are disclosed. The multilevel regenerative drive device may include an inverter having a plurality of power components and a converter having a plurality of power components. The multilevel regenerative drive device may also include a direct current (DC) link bridging the inverter and the converter, the DC link including a capacitor, an inverter neutral point, and a converter neutral point independent of the inverter neutral point. Alternatively, the inverter neutral point and the converter neutral point may be connected.Type: ApplicationFiled: December 18, 2013Publication date: January 5, 2017Inventors: Ismail Agirman, Steven M. Millett, Shashank Krishnamurthy, Yang Wang
-
Publication number: 20160308474Abstract: A regenerative drive (30) and method for providing power from such to at least one auxiliary power supply (41, 43) is disclosed. The drive may include a converter (32) and an inverter (34) connected by a DC bus (33), and a controller (54) configured to apply at least one of unipolar modulation and bipolar modulation to the converter (32) and the inverter (34), and to provide about half of the output voltage across the upper portion (130) of the DC bus (33) and about half of the output voltage across the lower portion (136) of the DC bus (33), when the upper and lower portions (130, 136) of the DC bus (33) are unevenly loaded. A first auxiliary power supply (41) may be connected to one of the upper and lower portions (130, 136) of the DC bus (33) and may receive power from the multilevel regenerative drive (30).Type: ApplicationFiled: December 18, 2013Publication date: October 20, 2016Inventors: Steven M. Millett, Ismail Agirman
-
Patent number: 8970152Abstract: An exemplary power supply assembly includes a drive device having a bus capacitor. A switch associated with an input side of the drive device selectively connects the drive device to a power supply. An inductor has an impedance that limits an amount of current supplied to the bus capacitor during an initial charging of the bus capacitor when the switch connects the input side of the drive device to the power supply. A restrictive circuit portion dampens a resonance effect of the inductor. The restrictive circuit portion has a resistance that allows the bus capacitor to charge quickly. The impedance of the inductor has a more significant effect on how quickly the bus capacitor charges than an effect of the resistance. A dampening factor of the restrictive circuit controls a voltage of the bus capacitor during the charging of the bus capacitor.Type: GrantFiled: July 30, 2010Date of Patent: March 3, 2015Assignee: Otis Elevator CompanyInventors: Daryl J. Marvin, Michael Mann, Steven M. Millett
-
Publication number: 20130119910Abstract: An exemplary power supply assembly includes a drive device having a bus capacitor. A switch associated with an input side of the drive device selectively connects the drive device to a power supply. An inductor has an impedance that limits an amount of current supplied to the bus capacitor during an initial charging of the bus capacitor when the switch connects the input side of the drive device to the power supply. A restrictive circuit portion dampens a resonance effect of the inductor. The restrictive circuit portion has a resistance that allows the bus capacitor to charge quickly. The impedance of the inductor has a more significant effect on how quickly the bus capacitor charges than an effect of the resistance. A dampening factor of the restrictive circuit controls a voltage of the bus capacitor during the charging of the bus capacitor.Type: ApplicationFiled: July 30, 2010Publication date: May 16, 2013Applicant: OTIS ELEVATOR COMPANYInventors: Daryl J. Marvin, Michael Mann, Steven M. Millett
-
Publication number: 20130119965Abstract: An exemplary power supply includes a low side switch and a high side switch. A driver controls operation of the high side switch. A bootstrap capacitor supplies power to the driver. An energy storage portion is in parallel with the bootstrap capacitor to provide control over whether a voltage of the bootstrap capacitor drops below a desired voltage. A voltage regulator is in parallel with the bootstrap capacitor for limiting current provided to the bootstrap capacitor and for regulating a voltage of the bootstrap capacitor.Type: ApplicationFiled: July 30, 2010Publication date: May 16, 2013Applicant: OTIS ELEVATOR COMPANYInventors: Daryl J. Marvin, Steven M. Millett