Abstract: A brushless, linear motor is provided in which the armature coils are cast in a resin to form an armature plate. A heat sink is attached along one edge of the plate with conductive pins (e.g. aluminum pins) extending through the plate and into the heat sink. Fans, attached to the heat sink, draw air across it in order to remove heat by convection. A wireless communications link transmits commutation data and/or armature position data to a motor controller.

Abstract: The armature coils of a brushless linear motor are cast in resin to form an armature plate. A heat sink is attached along one edge of the plate with conductive pins (e.g. aluminum pins) extending through the plate and into the heat sink. Fans, attached to the heat sink, draw air across it in order to remove heat by convection. A wireless communications link transmits commutation data and/or armature position data to a motor controller.

Abstract: A two wire, brushless, d.c. motor power control system employs a rechargeable d.c. power source (e.g. a battery or a capacitor) to provide power to the commutation position sensing electronics, and commutation logic during dynamic braking and also if desired, during motor start-up after stopping or reversing direction. Current limiting is provided by sensing the two-wire motor current and using the communicating logic to modulate the turn-off/turn-on time of the communicating switches.

Abstract: A power control and commutation network for a brushless DC motor includes a first section proximate the motor and a second section remote from and connected to the first section by a pair of conductors. Included in the first section is a servo control amplifier defining a main motor power supply and, in the second section, a polyphase brushless DC motor, a commutation module, an auxiliary power supply for the module, motor rotor position sensors and a switching network, the motor stator coils being connected through the switching network to the conductors. The amplifier may have an amplitude modulated DC output and the output of a high frequency oscillator in the second section is AC coupled to the conductors and the auxiliary power supply with its input is AC coupled between the conductors. Alternatively, the amplifier is PWM and the auxiliary power supply includes a rectifier with an input connected across the conductors and a voltage regulator controlling the output voltage.

Abstract: A blower motor providing vacuum as, for example, for a magnetic tape handler, is programmed to provide a constant vacuum in an environment of changing altitudes. The blower motor is controlled by a pressure transducer which speeds up the motor as the altitude is increased and slows down the motor as the altitude is decreased.

Abstract: A high-speed printer includes a standard printing element, such as a daisy wheel, a paper feed mechanism and a ribbon feed mechanism. All of these various devices are controlled by a single linear actuator which comprises an elongated cylindrical magnet, C-shaped in cross-section, through which a ferrous core axially extends. A plurality of separate armatures envelope the core in the air gap between the magnet and core and are adapted to move linearly upon application thereto of a control current. The armatures control, respectively, the movement of the carriage containing the printer element, the rotation of the printer element, the advancement of the paper feed mechanism and the incremental positioning in both directions of the ink ribbon.

Abstract: A door lock security system is disclosed in which each lock in a multiple lock system is modified by the addition of door lock security apparatus which, in electrical form, stores at least an individual key combination (and possibly several different levels of master key combinations) for the lock. Also, the conventional lock cylinder is replaced with a cylinder assembly which senses the magnetic reluctance state (high or low) of predetermined locations on a key substantially resembling a conventional cylinder lock key in size, weight and general shape and capable of mechanically operating the lock. The magnetic reluctance states of the predetermined locations digitally encode the key combination and the thus encoded combination is compared to the electrically stored one, disabling the mechanical operation of the lock unless the two combinations are identical.

Abstract: A one piece extrusion provides the base for a simple and effective vacuum tank for magnetic tape handlers. The extrusion carries longitudinal slots which accept stamped metal nuts. These nuts are readily positioned by sliding them along the slots. Slots along the edges of the extrusion are used to carry nuts holding hinges for a plastic cover over the tank front. Slots along the back and near the edges of the extrusion carry nuts for mounting the tank on the tape handler main frame. A longitudinal slot along the back of the extrusion and spaced in from one edge carries spring-loaded tubular inserts for attachment to the vacuum sensing tubes. Communication with the vacuum chamber is implemented by means of holes at appropriate places along the body of the extrusion.

Abstract: The vacuum for controlling tape loop tension in a magnetic tape handler is supplied by a low speed multiple stage vacuum blower and controlled by a low power solenoid and a flapper valve operated between two predetermined positions. In order to provide fast operation of the flapper valve in response to the low power solenoid a fast acting fluid amplifier is utilized between the solenoid and the flapper valve. The elimination of belts, gears and high speed blowers results in an unusually quiet system.