| 9106103 |
Unintteruptible power supply systems and methods employing on-demand energy storage |
Pradeep Kumar Nandam |
2015-08-11 |
| 7508094 |
UPS systems having multiple operation modes and methods of operating same |
Robert W. Johnson, Rune Lennart Jonsson, Ove Ohman, Kevin Lee, Pasi Taimela |
2009-03-24 |
| 7082040 |
Power factor corrected UPS with improved connection of battery to neutral |
William J. Raddi, Robert W. Johnson |
2006-07-25 |
| 6944035 |
Power factor corrected UPS with improved connection of battery to neutral |
William J. Raddi, Robert W. Johnson |
2005-09-13 |
| 6661678 |
Power factor corrected UPS with improved connection of battery to neutral and methods of operation thereof |
William J. Raddi, Robert W. Johnson |
2003-12-09 |
| 6400586 |
Power factor corrected UPS with improved connection of battery to neutral |
William J. Raddi, Robert W. Johnson |
2002-06-04 |
| 6262899 |
Power factor corrected UPS maintaining neutral integrity and methods of operation thereof |
William J. Raddi, Robert W. Johnson |
2001-07-17 |
| 6121756 |
Charger |
Robert W. Johnson, Steven R. Widener, Jeff Gucyski |
2000-09-19 |
| 6069412 |
Power factor corrected UPS with improved connection of battery to neutral |
William J. Raddi, Robert W. Johnson |
2000-05-30 |
| 5399913 |
Gate-drive circuit |
Steven R. Widener, Eric Menzel, George W. Oughton, Jr. |
1995-03-21 |
| 5185536 |
Uninterruptible power supply having improved battery charger |
Robert W. Johnson |
1993-02-09 |
| 4980812 |
Uninterrupted power supply system having improved power factor correction circuit |
Robert W. Johnson |
1990-12-25 |