Abstract: A motor driven actuator device includes an actuator motor; a controller; an input for receiving an external power supply; and a battery pack electrically connected to selectively drive the actuator motor, and electrically connectable to the external power supply for charging. During charging of the battery pack, the controller is configured to compare a measured charge level with a pre-determined charge level required to complete at least two battery shutdown events under battery power alone. During subsequent actuator device operation, the controller is configured to: determine if the external power supply is invalid, instruct a battery shutdown event causing the battery to be discharged, with enough charge in the battery to complete at least one further battery shutdown event; and, subsequently detect when the external power supply becomes valid, and resume actuator device operation under the external power supply, while simultaneously recharging the battery pack to at least the pre-determined charge level.

Abstract: A system and method to broadcast an optical signal through an amorphous medium, including a primary emitter capable of producing a primary optical signal during at least one broadcast period and capable of transmitting the primary optical signal through the amorphous medium. A secondary emitter, separate from the primary emitter and in operation during at least a portion of the broadcast period, produces a secondary emission detectable by a detector during the broadcast period. A signal entrainment controller, in communication with the primary emitter and the secondary emitter, synchronizes the secondary emitter with the primary emitter to generate a resultant signal of higher intensity than the primary signal by itself.