Abstract: A method for closed-loop control of a linear drive including a stator, a rotor configured for reciprocating movement along a drive axis therein, and a drive coil through which coil current flows, in particular for a linear compressor including a piston housing and a compressor piston configured for reciprocating movement along a piston axis therein, and driven by the linear drive wherein the coil current is subject to closed-loop control, the method including the steps of determining a target coil current and applying an actual coil current wherein the actual coil current and the target coil current are substantially the same value.

Abstract: A resistor member having a resistance value substantially equal to a resistance of a relay in an ON state is inserted into a current supply path which is not inserted with the relay in current supply paths for supplying currents from a driving circuit to a brushless motor. Further, in the driving circuit, widths of bus bars forming wirings are set such that resistances of the wirings (contact resistance) from a branch point on power source side to Hi side FET (source terminals thereof) are equal to each other and widths of bus bars forming the wirings are set such that the resistances of the wirings from a ground side branch point NL to Lo side FET (source terminals thereof) become equal to each other.

Abstract: A DC brushless motor structure comprises a cylinder-like base having a through-hole or a chamber. The through-hole acts as an axle hole for rotatably receiving a shaft of a rotor. Alternatively, the shaft of the rotor is rotatably received in the chamber. An axle hole is defined in an end of the base. Another axle hole is defined in a lid attached to an end of the base. The shaft of the rotor is rotatably received in the axle holes. At least two sets of windings are mounted to the base. Also mounted to the base is an IC control member electrically connected to the windings. A magnetic force is generated by a magnetic field that is created as a result of energizing the windings to thereby repulse the permanent magnet of the rotor having a north pole and a south pole, thereby driving the rotor to turn.

Abstract: A brushless DC motor includes a rotor having an iron core affixed to a motor shaft. Permanent magnets are affixed to the core and separated by aluminum inserts which are keyed to the core. An annular groove in one end of the rotor core is dimensioned so that its outer diameter coincides with the inner tips of the aluminum inserts. The inner diameter of the groove and its depth provide only minimal clearance around commutation transistors which occupy the space within the groove. The commutation transistors are affixed and electrically connected to a circuit board which, in turn, is secured to the motor body by attachment to a removable motor end plate. With this structure, the commutation transistors are surrounded on three sides by the rotor and are triggered by its drive magnets. This structure permits the commutation transistor to be triggered by a strong magnetic flux which is more accurately directed through the transistor at its switch plane.

Abstract: A control unit for controlling a vibratory bowl feeder which is effective to maintain, for varying feeder loads, a constant preselected amplitude of bowl feeder vibration at a vibratory frequency which coincides with the changing mechanical resonant frequency of the feeder system. The control unit includes a sensor which detects the amplitude and frequency of feeder bowl vibration, a frequency control loop and an amplitude control loop. The frequency control loop is responsive to the detected frequency of vibration and provides an oscillating signal which coincides with the resonant frequency of the system. The amplitude control loop is responsive to the detected amplitude of vibration and includes a variable gain amplifier which amplifies the oscillating signal to provide a feeder driving signal which causes the feeder to vibrate at the system resonant frequency at a preselected amplitude.

Abstract: An oscillating motor capable of 180.degree. displacement and return without return springs.