| ELECTRONIC SYSTEMS PROTECTION, INC. Patent applications |
| Patent application number | Title | Published |
|---|
| 20110102052 | Hybrid Switch Circuit - A hybrid switch circuit includes a hybrid switch that couples an input conductor connected to an AC power supply to an output conductor connected to a load. The hybrid switch includes a power semiconductor in parallel with an electromagnetic relay. A control circuit turns on the hybrid switch by turning on the power semiconductor at a zero-voltage crossing of the AC voltage to provide a conductive path and then closing the relay to provide a conductive bypass path that bypasses the power semiconductor. The control circuit turns off the hybrid switch by opening the relay and subsequently turning off the power semiconductor at a zero crossing of the load current. The control circuit operates in response to at least one switch control signal that indicates whether an operating fault condition exists. | 05-05-2011 |
| 20110063759 | Hybrid Switch Circuit - A hybrid switch circuit includes a hybrid switch that couples an input conductor connected to an AC power supply to an output conductor connected to a load. The hybrid switch includes a power semiconductor in parallel with an electromagnetic relay. A control circuit turns on the hybrid switch by turning on the power semiconductor at a zero-voltage crossing of the AC voltage to provide a conductive path and then closing the relay to provide a conductive bypass path that bypasses the power semiconductor. The control circuit turns off the hybrid switch by opening the relay and subsequently turning off the power semiconductor at a zero crossing of the load current. The control circuit operates in response to a hybrid switch control signal that indicates whether an operating fault condition exists. | 03-17-2011 |
| 20090115254 | Systems and Methods for Voltage SAG Compensation - A voltage sag compensation system includes a capacitor charging and discharging module connected to an AC rectifier and to an inverter, a two stage voltage detector configured to detect a degree of voltage sag that is present on a power line, and an inverter gating module selectively connectable to the power line in response to the two stage voltage detector and configured to provide gating signals to the inverter. The system further includes a low DC bus switch out module configured to monitor an output voltage of the capacitor charging and discharging module and to disable the inverter gating module from providing the gating signals to the inverter when voltage associated with the capacitor charging and discharging module falls below a predetermined value. | 05-07-2009 |
