Abstract: One embodiment of a method for activating a stimulus on a notification device includes encoding an instruction to activate the stimulus in a voltage dropout pulse of a synchronization protocol and sending the synchronization protocol, including the voltage dropout pulse, over a single two wire circuit to which a fire notification device and a mass notification device are coupled, where the notification device is the fire notification device or the mass notification device.

Abstract: One embodiment of a method for activating a stimulus on a notification device includes encoding an instruction to activate the stimulus in a voltage dropout pulse of a synchronization protocol and sending the synchronization protocol, including the voltage dropout pulse, over a single two wire circuit to which a fire notification device and a mass notification device are coupled, where the notification device is the fire notification device or the mass notification device.

Abstract: In one embodiment, the present invention is a method and apparatus for driving a light emitting diode strobe. One embodiment of a circuit for driving a current controlled light source includes an energy storage stage for storing a charge level and an energy delivery stage for drawing current from the energy storage stage and applying a fixed amount, of current to the current controlled light source.

Abstract: A method and apparatus for providing a volume control with DC supervision in a voice evacuation system are disclosed. In one embodiment, the apparatus is a volume control comprising a first input interface for receiving an audio signal, a first output interface for forwarding said audio signal to at least one audio device, and a second input interface for receiving an alarm signal. The apparatus also comprises a switch having a plurality of nodes, wherein at least one of the plurality of nodes is an unlabeled node, wherein the switch is in communication with the first input interface and the first output interface for controlling a volume of the audio signal that is sent to the at least one audio device. The apparatus also comprises a filter that is coupled to the unlabeled node of the switch.

Abstract: In one embodiment, the present invention is a method and apparatus for ground fault detection. One embodiment of a method for diagnosing a ground fault in a notification appliance circuit comprising a plurality of field wiring connections includes individually testing each of the plurality of field wiring connections until a source of the ground fault is detected and outputting a signal identifying the source of the ground fault.

Abstract: In one embodiment, the present invention is a method and apparatus for ground fault detection. One embodiment of a method for diagnosing a ground fault in a notification appliance circuit comprising a plurality of field wiring connections includes individually testing each of the plurality of field wiring connections until a source of the ground fault is detected and outputting a signal identifying the source of the ground fault.

Abstract: A method and apparatus for providing a volume control with DC supervision in a voice evacuation system are disclosed. In one embodiment, the apparatus is a volume control comprising a first input interface for receiving an audio signal, a first output interface for forwarding said audio signal to at least one audio device, and a second input interface for receiving an alarm signal. The apparatus also comprises a switch having a plurality of nodes, wherein at least one of the plurality of nodes is an unlabeled node, wherein the switch is in communication with the first input interface and the first output interface for controlling a volume of the audio signal that is sent to the at least one audio device. The apparatus also comprises a filter that is coupled to the unlabeled node of the switch.