Abstract: Certain aspects of the present disclosure are generally directed to circuitry and techniques for adjusting an audio signal to avoid undesirable system behavior under low alternating-current (AC) line voltage and high volume conditions. For example, certain aspects provide an apparatus for audio amplification. The apparatus generally includes an amplifier, a supply voltage generation circuit having an input coupled to an input voltage node of the apparatus and an output coupled to a supply voltage terminal of the amplifier, the supply voltage generation circuit having a transformer, a primary winding of the transformer being coupled to the input voltage node, a peak voltage detector circuit configured to detect a peak voltage at a secondary winding of the transformer, and a controller circuit configured to adjust an input audio signal of the amplifier based on the detected peak voltage.

Abstract: Certain aspects of the present disclosure are generally directed to circuitry and techniques for adjusting an audio signal to avoid undesirable system behavior under low alternating-current (AC) line voltage and high volume conditions. For example, certain aspects provide an apparatus for audio amplification. The apparatus generally includes an amplifier, a supply voltage generation circuit having an input coupled to an input voltage node of the apparatus and an output coupled to a supply voltage terminal of the amplifier, the supply voltage generation circuit having a transformer, a primary winding of the transformer being coupled to the input voltage node, a peak voltage detector circuit configured to detect a peak voltage at a secondary winding of the transformer, and a controller circuit configured to adjust an input audio signal of the amplifier based on the detected peak voltage.

Abstract: A speaker includes an electroacoustic driver, a first wall that includes an integral suspension element, and a mass suspended by the suspension element to form a passive radiator. Acoustic energy from the electroacoustic driver can cause the passive radiator to move.

Abstract: A deployable speaker includes a driver and an acoustic enclosure made up of a multiplicity of panels. The driver is secured to one of the panels. The acoustic enclosure is deployable from a closed state to a deployed state. All of the panels which make up the enclosure are unitary and formed from a single sheet of composite material. The composite material has an interior layer that includes a first type of material which is skinned in a second type of material.

Abstract: A speaker includes an electroacoustic driver, a first wall that includes an integral suspension element, and a mass suspended by the suspension element to form a passive radiator. Acoustic energy from the electroacoustic driver can cause the passive radiator to move.

Abstract: A speaker includes an electroacoustic driver, a first wall that includes an integral suspension element, and a mass suspended by the suspension element to form a passive radiator. Acoustic energy from the electroacoustic driver can cause the passive radiator to move.

Abstract: A deployable speaker includes a driver and an acoustic enclosure made up of a multiplicity of panels. The driver is secured to one of the panels. The acoustic enclosure is deployable from a closed state to a deployed state. When one of the panels is moved by a user from the closed to the deployed state, all but one of the remaining panels are simultaneously moved from the closed to the deployed state.

Abstract: A deployable speaker includes a driver and an acoustic enclosure made up of a multiplicity of panels. The driver is secured to one of the panels. The acoustic enclosure is deployable from a closed state to a deployed state. All of the panels which make up the enclosure are unitary and formed from a single sheet of composite material. The composite material has an interior layer that includes a first type of material which is skinned in a second type of material.

Abstract: A speaker includes an electroacoustic driver, a first wall that includes an integral suspension element, and a mass suspended by the suspension element to form a passive radiator. Acoustic energy from the electroacoustic driver can cause the passive radiator to move.

Abstract: A deployable speaker includes a driver and an acoustic enclosure made up of a multiplicity of panels. The driver is secured to one of the panels. The acoustic enclosure is deployable from a closed state to a deployed state. When one of the panels is moved by a user from the closed to the deployed state, all but one of the remaining panels are simultaneously moved from the closed to the deployed state.

Abstract: An autopilot system for a vessel such as a boat receives a pre-set heading direction set by e.g. the user and also receives the apparent orientation (heading) from a heading sensor. The difference between the pre-set heading direction and the actual heading is then determined and a correction signal is generated in dependence on that difference, which correction signal is then used to control the orientation of the vessel by e.g. generating a rudder correction signal which varies the position of the rudder. In the present invention, the correction signal is further dependent on the difference between the actual heading and a reference direction such as magnetic North or South. In this way errors due to differences between the apparent orientation as detected by the heading sensor and the actual orientation of the vessel may be corrected.

Abstract: An autopilot system for a vessel such as a boat has an autopilot unit connected via a drive to the rudder or other direction determining means of the vessel. When the autopilot unit is operating normally, direction information from e.g. a heading sensor is processed by the autopilot unit and the drive is controlled by the autopilot unit to determine the appropriate position of the rudder. The rudder is also linked to a steering wheel or other manual steering arrangement. When the steering wheel is moved during normal operation of the autopilot unit, this causes an interference with the control of the rudder by the drive and, if this interference has sufficient magnitude and duration, this triggers override of the autopilot unit, returning the vessel to manual control via the steering wheel. The override may alternatively be triggered by detection of rudder movement by a sensor.

Abstract: An integrated circuit voltage chop circuit for regulating the current in an inductive load is of the type having a fixed off time. A current-sensing comparator produces a reset signal when the current through the driver exceeds a predetermined peak amplitude. A load driver transistor is turned on and off according to the state of a bistable memory elememt, e.g. a flip flop. An external capacitor and external series resistor are connected to the integrated circuit and they determine the driver off time. A voltage comparator having hysteresis produces a high output logic level when the capacitor charges to a predetermined voltage which sets the flip flop and begins to slowly discharge the capacitor. When the capacitor discharges to a lower predetermined voltage, the voltage comparator output goes to a low logic level turning on a shorting transistor that quickly discharges the capacitor completely.