Abstract: A system for controlling a brushless motor includes drive circuitry in communication with the brushless motor and a primary control device in communication with the drive circuitry. The system also includes a secondary control device in communication with the drive circuitry and a multiplexer for selectively providing an output of the primary control device or an output of the secondary control device to the drive circuitry, wherein the output of the primary control device is provided to the drive circuitry when the primary control device is operating normally.

Abstract: Systems, methods, devices, and computer readable media for controlling a digging operation of an industrial machine. A method includes determining a hoist bail pull associated with the industrial machine, determining a crowd torque limit value for a crowd drive based on the determined hoist bail pull of the industrial machine, and setting a crowd torque limit of the crowd drive to the crowd torque limit value to limit a torque associated with a crowd motor to the crowd torque limit value.

Abstract: A motor control device is electrically connected with a motor. The motor control device includes a controller and a driving circuit. The controller has a default value of time and generates a first driving signal and a second driving signal. The driving circuit includes a first switching element and a second switching element, the first switching element and the second switching element receive the first driving signal and the second driving signal respectively, and the first switching element and the second switching element are switched on or switched off alternately according to the first driving signal and the second driving signal respectively, so as to drive the motor to operate.

Abstract: A fan drive apparatus includes a first fan, a second fan configured to form an air flow space, which has an intake side and an exhaust side, in cooperation with the first fan, a first drive circuit and a second drive circuit configured to output drive voltages to drive the first fan and the second fan respectively, a current detection unit configured to detect a drive current for the second drive circuit when the first fan and the second fan are driven, and a control unit configured to control the second drive circuit to change the drive voltage applied to the second fan, and determine a drive voltage so that a variation amount of the drive current detected by the current detection unit with respect to a change of the drive voltage is equal to or less than a predetermined value.

Abstract: When driving a plurality of paralleled feed drive mechanisms individually by servo motors (105, 106), torque of the servo motors (105, 106) is detected, and in dependence on a difference therebetween, a position command of servo motor (106) at a slave side is corrected, so that torque of the slave side servo motor (106) is matched to to torque of servo motor (105) at a master side.

Abstract: In a tape transport for recording and/or reproducing signals by means of a recording medium using separate winding motors for driving the winding plates, the drive of the winding motors servo units is constructed as open-loop control devices and/or closed-loop control devices. Such servo units can advantageously be used for open-loop control and/or closed-loop control of the drive of the winding motor even during a braking operation.

Abstract: Latching components of a padlock are driven by a motor between latched and released positions. An encoder element with associated optical elements provides position information to a control circuit. The control circuit correlates the position information with the signal directing power to the motor so that the motor is precisely controlled for moving the latching elements between release and latch. If the motor jams (sensed by overcurrent), it is operated briefly in alternating directions to try and dislodge the grit or ice causing the jam. The padlock shackle is latched into place by balls which are driven into recesses in the shackle legs. The use of plural balls on at least one side helps isolate the drive motor and gears from grit that may enter through the padlock's top shackle holes.

Abstract: A system, which may be a cooling system for a motor vehicle engine, has two direct current motors together with switching circuits which provide selective connection of the windings of the two motors to a direct current voltage source in such a way as to obtain different operating modes for each motor. One of the motors has four brushes, the first of which is permanently connected to the first polarity of the source, while its second, third and fourth brushes are arranged so that they can be connected to the appropriate source polarities respectively through either three interruptors or two. The second motor has two brushes permanently connected, respectively, to the same first source polarity and to the third or fourth brush of the first motor.

Abstract: Semiconductor components electrically connected in parallel are divided into a plurality of groups, with the control terminals of the semiconductor components constituting each group being connected in common to form a control terminal of the group, wherein the control terminals of the groups are mutually independent. A load current is limited by allowing specified ones of said semiconductor components to become conductive. Control of the load current is made possible without accompanying wasteful power dissipation.

Abstract: A controller for a wheelchair motor or the like including two power transistors each having a base and a collector-emitter path, the collector-emitter paths being connected in parallel. At least one oscillator and a flip-flop are provided to supply pulses alternately to the transistor bases so that the transistors are never turned on simultaneously. In another system, two or more transistors are connected in parallel and are gated on in digital succession responsive to the outputs of a ring counter.

Abstract: The invention pertains to a control system (46) for controlling the supply of power to a motor (12) to produce plugging electrical braking and current limit control, including a circuit (60) for controlling the direction of energization of the motor (12), a circuit (88) for generating digital numbers representing command motor speeds, a circuit (14) for generating a data signal representing a plugging condition, a programmable data processor (18) for generating pulse trains in dependence on the plugging condition, and a power transistor element (40) for coupling power to the motor (12) in response to the pulse trains. By using state-of-the-art digital, integrated circuit and software technology, prior, essentially linear or discrete component technology, which is relatively unreliable, expensive and slow, need not be used.

Abstract: The invention pertains to a control circuit (10) for controlling the speed of a pair of motors (12,14), including a pair of switching elements (68,74) coupling power to the motors (12,14), a pair of controllable circuits (64,74) for driving the switching elements (68, 74), a circuit (36) for generating digital numbers representing the same command speed for each of the motors (12,14), a circuit (38) for generating digital numbers representing differential command speeds for the motors (12,14), and a data processor (56) for controlling the pair of controllable circuits (64,74) in response to the digital numbers. By utilizing digital and integrated circuit technology, prior, essentially linear, control apparatus, which are relatively unreliable, expensive and slow, need not be used.

Abstract: A method and apparatus for maintaining predetermined speed ratios between at least two motions are described. The speeds of the motive power sources for the motions are controlled by signals having values proportional to the ratio of those speeds, and in the alternative, if lower in value, reference signal which may be generated by an operator. The invention is described in connection with its application in a power shovel where it controls the ratio of crowd speed to hoist speed.