Abstract: A bracing structure for a soundboard for a musical instrument is disclosed, the bracing structure being a unitary sheet structure having a plurality of elongate semi-tubular elements. Each of the elongate semi-tubular elements has a length, a thickness, a width, a height and an interior resonance space. The sheet structure may be formed of two or more layers. The elongate semi-tubular elements function as traditional braces, however, the shape of the elongate semi-tubular elements may be modified to provide a desired tonal quality.

Abstract: A musical system. At least some of the illustrative embodiments are systems including: a frame with an interior cavity, a tuning system coupled within the interior cavity of the frame, the tuning system configured to be accessed by way of an aperture through of the frame, and a drum head retained at a first end of the frame, wherein the tuning system configured to apply uniform pressure that circumscribes an axis of interior surface of the drum head.

Abstract: A soundhole accessible musical instrument control platform mounted inside the body of a musical instrument requires no physical alterations to the instrument, allowing the user convenient and ergonomic access to the control platform through the soundhole while using the musical instrument. The control platform includes a circuit platform, mounted inside the instrument with adhesives, separably attached to a mounting bracket. Control detents and markings are easy to feel and to read and thus provide feedback for control position and the relative degree of effect. The controls are surrounded by a cosmetic bezel that hides the actual mounting mechanism and circuitry. Any combination of controls, circuitry, and sensors may be used. Power is either provided onboard or offboard. An output connector may be integrated into the circuit platform or via an endpin jack.

Abstract: A snare drum including a drum shell having an upper head and a lower head mounted thereon and a frame for holding a plurality of snare wires. The frame arranges the snare wires to be in contact with the lower head or to be spaced from the lower head. The snare drum includes a first latched member and a second latched member respectively located at opposite ends of the frame at an outer side the drum shell. An attachment mechanism is located on the drum shell for arranging the frame on a surface of the lower head. The attachment mechanism includes a first latching member and a second latching member arranged between the drum shell and the first and second latched members for separably latching the first and second latched members, respectively.

Abstract: A brushless motor control apparatus detects a phase current flowing in a brushless motor, converts the phase current to a vector current including a d-axis current of a magnetic flux direction component and a q-axis current of a torque direction component orthogonal to the d-axis current, calculates a vector voltage instruction value based on differences between a vector current and a vector current instruction value, calculates a phase voltage instruction value and controls rotation of the brushless motor based on the phase voltage instruction value. The apparatus further calculates electric power produced in the brushless motor and protects the brushless motor based on the magnitude of electric power.

Abstract: A brushless DC motor apparatus includes a housing and a stator assembly coupled to the housing. The apparatus further includes a magnetic rotor assembly rotatably coupled to the housing. The magnetic rotor assembly is configured to rotate within the housing in response to electric currents through windings of the stator assembly. The apparatus further includes position sensors which are configured to provide position signals identifying angular position of the magnetic rotor assembly relative to the stator assembly. Each position sensor includes (i) a Hall-effect sensor disposed distally from the windings, and (ii) magnetic circuit members having first end portions adjacent the windings and proximate rotor magnets and second end portions adjacent the Hall-effect sensor. Use of such magnetic circuit members enables the Hall-effect sensors to reside a greater distance from the windings vis-à-vis conventional brushless DC motors which position sensors adjacent to stator coils within motor casings.

Abstract: A system for controlling the speed of a brushless repulsion motor having a series of switches mounted on a rotating armature for shorting circumferentially spaced armature coils comprising first stationary signaling means and a plurality of rotating detectors for activating said switches; second stationary signaling means for speed control; a plurality of markers on the rotating armature; a speed detector for detecting the speed of the rotating markers and generating a speed feedback signal; means for generating a speed command signal; an error calculator for comparing the speed feedback and speed command signals and generating an error signal; and a controller for controlling the signaling means based on the error signal.

Abstract: A unipolar drive includes a booster, an energy storage module, and a unipolar inverter. The booster increase a voltage received from a power supply to produce an energy output. The energy storage module store at least some of the energy output by the booster. The unipolar inverter energizes windings of a motor using energy from the booster and returns energy from the windings to the booster when the windings are not being energized.

Abstract: In a servomotor controller, when a comparing circuit (70) detects that a position of an object to be controlled has been achieved to a target position, an operation inhibiting signal generating section (71) supplies an operation inhibiting signal (71a) to an operation permitting/inhibiting signal-processing section (66), and obtains an operation stopped state of an H bridge-driving processing section (67) for controlling driving of a motor. A LIN communication processing section (61) receives information to a self address supplied from a superordiante device, and outputs a forced operation (recovery) request (61R) in the received information. The operation state of the H bridge-driving processing section (67) is obtained through an operation permitting trigger signal generating section (65) and the operation permitting/inhibiting signal-processing section (66) through the H bridge-driving processing section (67).

Abstract: An electric motor car controller includes a voltage detector for detecting the voltage across a filter capacitor, an energy amount calculator for calculating the amount of energy of the filter capacitor from the output of the voltage detector, a frequency band component detector for extracting a given frequency band component included in the amount of energy, a frequency band component coefficient unit for multiplying the frequency band component by a coefficient and outputting a q-axis current command correcting value, and a q-axis current command correcting value adder for adding a q-axis current command correcting value to the q-axis current command value to correct the q-axis current command value.