Abstract: An over-voltage comparator and shutdown circuit for a power converter, comprising at least a first voltage divider connected between ground and a monitored voltage, the voltage divider including a first resistor and a second resistor, a switch mode regulator connected to a primary switch of the power converter, and a first threshold comparator, wherein a monitored input of the first threshold comparator is connected between the first resistor and the second resistor, an anode of the first threshold comparator is connected to ground, and a cathode of the first threshold comparator is connected to the switch mode regulator, and wherein the monitored voltage is voltage at an end of a primary winding of the power converter. An auxiliary output circuit of the power converter may be provided having a first output providing the monitored voltage and a second output providing power to the switch mode regulator.

Abstract: A device for communicating and providing power over a cable having at least two conductors comprises an inductor having two secondary windings and one primary winding, and a transceiver coupled to the primary winding of the inductor, the two secondary windings of the inductors being coupled to two of the at least two conductors of the cable. Further, a voltage signal provided by the secondary windings of the inductors to the conductors varies symmetrically from an average potential. The inductor of the device can also comprise two primary windings connected in series and two secondary windings connected in series, the secondary windings also connected to two of the at least two conductors in the cable, wherein the voltage signal provided to the two conductors from the secondary windings varies symmetrically from an average potential.

Abstract: An over-voltage comparator and shutdown circuit for a power converter, comprising at least a first voltage divider connected between ground and a monitored voltage, the voltage divider including a first resistor and a second resistor, a switch mode regulator connected to a primary switch of the power converter, and a first threshold comparator, wherein a monitored input of the first threshold comparator is connected between the first resistor and the second resistor, an anode of the first threshold comparator is connected to ground, and a cathode of the first threshold comparator is connected to the switch mode regulator, and wherein the monitored voltage is voltage at an end of a primary winding of the power converter. An auxiliary output circuit of the power converter may be provided having a first output providing the monitored voltage and a second output providing power to the switch mode regulator.

Abstract: A control circuit configured to control an electromechanical brake is provided. The control circuit includes: a switching regulator configured to control a magnitude of voltage applied to a brake coil of the electromechanical brake; wherein said switching regulator includes at least one semiconductor switch, one diode, one capacitor and one inductor; the control circuit is configured such that, in operation, at least one signal from a process sub-system specifies the magnitude of the voltage for the brake coil; and at least one brake applying control signal from a safety sub-system can cause the brake coil voltage to be reduced to a level low enough to apply the brake by opening a switch and each brake applying control signal from the safety sub-system has a corresponding diagnostic feedback signal to the safety sub-system that indicates the state of the corresponding switch. A method and a system are disclosed.

Abstract: A device for communicating and providing power over a cable having at least two conductors comprises a first inductor having a primary and a secondary winding, a second inductor having a primary and a secondary winding, the primary winding of the second inductor being coupled at one end to the primary winding of the first inductor, each of the secondary windings of the first and second inductors being coupled to one of the at least two conductors in the cable. The device further includes a transceiver coupled to the primary windings of the first and second inductors, wherein the first inductor is coupled to local ground potential, in a manner that varies the potential of each of the said conductors symmetrically from an average potential.

Abstract: A device for communicating and providing power over a cable having at least two conductors comprises an inductor having two secondary windings and one primary winding, and a transceiver coupled to the primary winding of the inductor, the two secondary windings of the inductors being coupled to two of the at least two conductors of the cable. Further, a voltage signal provided by the secondary windings of the inductors to the conductors varies symmetrically from an average potential. The inductor of the device can also comprise two primary windings connected in series and two secondary windings connected in series, the secondary windings also connected to two of the at least two conductors in the cable, wherein the voltage signal provided to the two conductors from the secondary windings varies symmetrically from an average potential.

Abstract: A control circuit configured to control an electromechanical brake is provided. The control circuit includes: a switching regulator configured to control a magnitude of voltage applied to a brake coil of the electromechanical brake; wherein said switching regulator includes at least one semiconductor switch, one diode, one capacitor and one inductor; the control circuit is configured such that, in operation, at least one signal from a process sub-system specifies the magnitude of the voltage for the brake coil; and at least one brake applying control signal from a safety sub-system can cause the brake coil voltage to be reduced to a level low enough to apply the brake by opening a switch and each brake applying control signal from the safety sub-system has a corresponding diagnostic feedback signal to the safety sub-system that indicates the state of the corresponding switch. A method and a system are disclosed.

Abstract: Systems and methods of supporting communications over a common network connection in a master-slave field bus network with a first type of packet formatted with a time-sensitive protocol and a second type of packet formatted with a non-time-sensitive protocol are provided. The slave devices are configured with filters to prevent the first type of packet from reaching a configurator and the second type from reaching a master device. The slave devices are also configured with arbitration logic so that the packets formatted with the time-sensitive protocol are provided with a priority over the packets formatted with the non-time-sensitive protocol.

Abstract: A device for communicating and providing power over a cable having at least two conductors comprises a first inductor having a primary and a secondary winding, a second inductor having a primary and a secondary winding, the primary winding of the second inductor being coupled at one end to the primary winding of the first inductor, each of the secondary windings of the first and second inductors being coupled to one of the at least two conductors in the cable. The device further includes a transceiver coupled to the primary windings of the first and second inductors, wherein the first inductor is coupled to local ground potential, in a manner that varies the potential of each of the said conductors symmetrically from an average potential.

Abstract: Systems and methods for providing Safe Torque Off signals using communication wires used for control signaling. Single channel Safe Torque Off signals can be provided as a DC voltage or AC voltage across two sets of twisted pair wires. Alternatively, two Safe Torque Off signals can be provided using both a DC voltage and an AC voltage across the two sets of twisted pair wires.

Abstract: Systems and methods of supporting communications over a common network connection in a master-slave field bus network with a first type of packet formatted with a time-sensitive protocol and a second type of packet formatted with a non-time-sensitive protocol are provided. The slave devices are configured with filters to prevent the first type of packet from reaching a configurator and the second type from reaching a master device. The slave devices are also configured with arbitration logic so that the packets formatted with the time-sensitive protocol are provided with a priority over the packets formatted with the non-time-sensitive protocol.

Abstract: Systems and methods for providing Safe Torque Off signals using communication wires used for control signaling. Single channel Safe Torque Off signals can be provided as a DC voltage or AC voltage across two sets of twisted pair wires. Alternatively, two Safe Torque Off signals can be provided using both a DC voltage and an AC voltage across the two sets of twisted pair wires.

Abstract: A decentralized motor drive arrangement provides high-voltage operational power and low-voltage standby power from a centralized distribution unit to remote motor drives using the same pair of interconnection power wires. The distribution unit includes a low-voltage power source which has one output terminal diode coupled to one of the output terminals of a high-voltage power source to form one output wire of the distribution unit. The other output terminals of the low-voltage and high-voltage power sources are directly coupled to form the other distribution unit outgoing power wire.

Abstract: A system and method are provided for improved dynamic braking in AC motors with an electronic drive, and more particularly to using a current regulation circuit to control the current supplied to the motor to be in phase with the internal EMF voltage of the motor such that the braking torque of the current is maximized per ampere of dynamic braking current when needed to stop the motor in case of a control failure or emergency. A current regulator produces a voltage command to the motor based on the current command input. The motor is still controlled by a d-q current regulator and the q-axis (torque axis) voltage is driven to zero while the d-axis (non-torque axis) is left in current control with a zero current command. This way the motor internal voltage drives a current in the terminals of the motor but the current is in phase with the internal voltage of the motor.

Abstract: A system and method are provided for improved dynamic braking in AC motors with an electronic drive, and more particularly to using a current regulation circuit to control the current supplied to the motor to be in phase with the internal EMF voltage of the motor such that the braking torque of the current is maximized per ampere of dynamic braking current when needed to stop the motor in case of a control failure or emergency. A current regulator produces a voltage command to the motor based on the current command input. The motor is still controlled by a d-q current regulator and the q-axis (torque axis) voltage is driven to zero while the d-axis (non-torque axis) is left in current control with a zero current command. This way the motor internal voltage drives a current in the terminals of the motor but the current is in phase with the internal voltage of the motor.

Abstract: The present invention is an apparatus for indicating the instantaneous position of a movable member along a range of motion with respect to a reference position. The apparatus includes a magnetic body that is fixedly attached to the movable member. The body has a contoured surface to control the shape of a magnetic field relative to position, and further includes at least two magnetic field sensors. Each of the sensors is disposed adjacent to the contoured surface of the magnetic body and fixed with respect to the reference position, and is positioned apart from the other sensors, so as to form a non-uniform gap between the contoured surface and each of the magnetic field sensors. Each of the sensors produces a position dependent signal corresponding to a value of the magnetic field. The apparatus further includes a decoding circuit electrically coupled to each of the magnetic field sensors so as to receive each of the position dependent signals.

Abstract: A method for controlling a motorized balancing transporter that has two wheels in contact with the ground in normal operation. A signal substantially proportional to the shaft velocity is produced, and, at a rate less than 200 times per second, a voltage is calculated based at least on the shaft velocity signal and a specified transporter velocity and a voltage is applied to the motor based on the calculated voltage. A method is also provided for yaw control of the motorized balancing transporter that includes calculating a command to a motor amplifier based on balancing requirements of the transporter and augmenting the command to the motor amplifier based on a specified direction of motion.

Abstract: An apparatus, preferably in the form of a resolver to digital converter for converting the amplitude modulated, encoded signals into digital signals representative of the velocity and position is described. The apparatus is of the type that includes an electronic control transformer circuit for providing respective products of sine and cosine analog signals respectively times the cosine and sine of the digital position signals and for differencing the products so as to produce an analog AC error signal. The improvement comprises means for converting the analog AC error signal into a digital DC error signal and a digital accumulator for time integrating the DC error signal to generate the digital position signal. In a preferred embodiment the output of the accumulator is digitally modulated so as to provide the digital position signal as a bit-reduced feedback signal to the electronic control transformer.

Abstract: A new sensor means for accurately measuring the current flowing in an electronically controlled switch is presented. An ac coupled current sensor is arranged in circuit with the electronically controlled power switch. The output of the sensor channel is zeroed (or restored to another fixed independent level) whenever the power switch is in the OFF condition. Using the natural modulation of the power switch itself to coordinate the reconciling of the sensor output level with the OFF state of the power switch helps restore to the dc level lost through ac coupling. This coordination of the sensor with the switch itself reduces dc offset and drift and allows ac coupling, which removes dc common mode and increases primary current sensor flexibility, all without adding complexity. A plurality of such sensors can be combined to measure indirectly the load current from a plurality of switches according to Kirchoff's Current Law.

Abstract: A fume hood controller system in which the sash position is monitored by a transducer which provides a signal indicative of the area of the hood opening. A variable speed motor controller is responsive to the sash position signal to provide a fan speed which varies in a substantially continuous and linear manner as a function of the sash opening. In an alternate embodiment, the air flow through the hood is controlled by a damper or similar device. Several embodiments are shown in which the present invention may be used to control a fume hood system in which a blower exhausts a plurality of fume hoods while maintaining a substantially constant face velocity in each hood.