Abstract: A method and apparatus for operating an overvoltage response for an electric machine includes opening a first switching element and a second switching element in response to an overvoltage condition. In the instance that the overvoltage condition persists, the method and apparatus can further open a third switchable element to cease the overvoltage condition.

Abstract: A method and apparatus for operating an overvoltage response for an electric machine includes opening a first switching element and a second switching element in response to an overvoltage condition. In the instance that the overvoltage condition persists, the method and apparatus can further open a third switchable element to cease the overvoltage condition.

Abstract: Several embodiments provide wireless extensions to an irrigation controller system and related methods of use, as well as other improvements to irrigation control equipment. In one implementation, an irrigation control system includes a transmitter unit including a controller and having a connector to be coupled to an irrigation controller having station actuation output connectors. The controller is configured to receive an indication that the irrigation controller has activated an irrigation station, and is also configured to cause the transmitter unit to transmit a wireless activation signal responsive to the indication. A receiver unit is coupled to an actuator coupled to an actuatable device, such as an irrigation valve, the actuator configured to actuate the irrigation valve to control the flow of water therethrough. The receiver unit receives the wireless activation signal and in response, causes the actuator to actuate the actuatable device.

Abstract: Several embodiments provide wireless extensions to an irrigation controller system and related methods of use, as well as other improvements to irrigation control equipment. In one implementation, an irrigation control system includes a transmitter unit including a controller and having a connector to be coupled to an irrigation controller having station actuation output connectors. The controller is configured to receive an indication that the irrigation controller has activated an irrigation station, and is also configured to cause the transmitter unit to transmit a wireless activation signal responsive to the indication. A receiver unit is coupled to an actuator coupled to an actuatable device, such as an irrigation valve, the actuator configured to actuate the irrigation valve to control the flow of water therethrough. The receiver unit receives the wireless activation signal and in response, causes the actuator to actuate the actuatable device.

Abstract: Methods and apparatuses for testing the installation of sensors, irrigation system components and controllers are provided. An apparatus or sensor unit is for use with an irrigation system and comprises a processor and a sensor coupled to the processor and adapted to provide a sensor response. The sensor can be a water sensor, a temperature sensor, a humidity sensor, a ground moisture sensor, a solar radiation sensor, a wind speed sensor, or a water flow rate sensor, among others. A communication circuit is coupled to the processor which in turn can cause the communication circuit to transmit a first signal in response to the sensor response. The processor can further cause the communication circuit to transmit a test signal having a signal strength that is less than the strength of the first signal to simulate the deteriorated conditions that can be present during a transmission.

Abstract: A sensor for detecting the flame occurring during a flashback condition in the fuel nozzle of a lean premix combustion system is presented. The sensor comprises an electrically isolated flashback detection electrode and a guard electrode, both of which generate electrical fields extending to the walls of the combustion chamber and to the walls of the fuel nozzle. The sensor is positioned on the fuel nozzle center body at a location proximate the entrance to the combustion chamber of the gas turbine combustion system. The sensor provides 360° detection of a flashback inside the fuel nozzle, by detecting the current conducted by the flame within a time frame that will prevent damage to the gas turbine combustion system caused by the flashback condition.