Abstract: A heat sink apparatus and method for making the same including a metallic main body portion and a hollow metallic fluid conduit assembly disposed within the main body portion and a binder material disposed between the assembly and the main body portion wherein the binder material prohibits alloying between the materials used to form each of the assembly and the body portion. The invention includes a supporter for maintaining the tube conduit position, both laterally and vertically during formation.

Abstract: A method and apparatus for compensating for deviations in the alternating voltage produced by a PWM inverter. The necessary sequence in which inverter components must be triggered results in voltage error pulses that accumulate over time and result in deviations from ideal voltage at motor terminals. By allowing the error pulses to continue and adjusting the trigger times to compensate for the error pulses, the effect of the error pulses is negated and the voltage deviations are eliminated.

Abstract: A heat sink apparatus including a fluid conduit within a body portion wherein the body portion includes at least first and second walls which are in different planes, each wall forming at least one mounting surface, the conduit passing though each wall and, the apparatus also including at least two electronic devices, at least one device mounted to each of the mounting surfaces for dissipating heat, the assembly having a relatively small volume.

Abstract: A method and apparatus for eliminating greater than twice motor over voltage by altering modulating signals provided to a PWM controller which in turn provides firing pulses to a PWM inverter. The modulating waves are altered by either tying them to positive or negative DC buses or limiting their maximum magnitudes when their instantaneous characteristics are known to cause greater than twice overvoltage. The modulating waveforms are altered in a symmetrical fashion so that the resulting fundamental terminal voltages remain essentially unchanged.

Abstract: An apparatus for use with a switch-mode rectifier for minimizing DC bus voltage without causing current distortion, the apparatus monitoring rectifier saturation and decreasing DC bus voltage until the rectifier is near a saturation point and then maintaining the DC bus voltage at that point.

Abstract: An apparatus including only first and second sensors for determining three phase motor currents and providing complete over-current protection to a three phase motor having three input lines. The first and second sensors measure first and second combined currents wherein the first combined current is the current through the first and second lines and the second combined current is at least the current through the second line and at least one of the first or second combined currents include the third current. The first and second combined currents are used to provide the over-current protection and are used to determine all of the first, second and third line currents.

Abstract: A rotor supporter for use in superconducting motors including first and second torque tubes secured between first and second rotor shaft ends and a rotor winding support wherein the support is essentially hollow and the tubes are essentially or entirely located inside the support thereby reducing overall rotor length.

Abstract: An apparatus for compensating for turn on delay distortions generated by a PWM controller. When turn on delay compensation is added to a PWM controller command signal and current zero crossings are inaccurately determined, compensation at the zero crossings causes further distortion which is reflected in a d and q-axis current vector frequency. Deviations from an ideal vector frequency are identified and used to modify command voltages to eliminate the zero crossing errors.

Abstract: A method to be used with a programmable controller that can communicate with peripheral devices in two protocols, the method for automatically switching controller communication between the two protocols when the protocol used by a peripheral device is different than the protocol currently being used by the controller.

Abstract: A PWM based converter including a Y-.DELTA., Y--Y transformer (or a .DELTA.--.DELTA., .DELTA.-Y transformer) wherein the Y-.DELTA. portion of the transformer phase shifts input voltage by 30.degree. with respect to the Y--Y portion of the transformer and thereby eliminates many low order supply line harmonics. The rectifier also includes two series connected PWM switching rectifiers, one rectifier receiving input voltages from the Y--Y portion of the transformer and the other rectifier receiving input voltages from the Y-.DELTA. portion of the transformer, and a controller for controlling the first and second rectifiers so as to eliminate low order harmonics on the supply lines that are not eliminated by the transformer. A capacitive bank is required between each rectifier and the transformer.

Abstract: A termination network to be used with an induction motor for eliminating voltage reflections and voltage surges due to voltage reflections, the network includes a resistive element in series with a capacitive element between each two voltage supply lines. The capacitive element initially operates like a short so that a resistive element terminates each line for a short period, the termination network impedance matches the line impedance, and reflection is eliminated. After a voltage pulse passes to a stator winding the capacitor element is charged and the resistive element is effectively removed from the line circuit.

Abstract: A method and apparatus to be used with a peer-to-peer network including a plurality of separate controllers which can control each other, the method and apparatus to be used to determine when a fault conditions occurs when one controller which has controlled a different controller is rendered incapable of network communication. In the present invention, each individual controller includes a control list which tracks all of the other controllers that have controlled the individual controller. When one of the controllers on a control list is rendered incapable of communicating with the individual controller, the controller that is incapable of communicating is cleared from the control list associated with the individual controller and the tools associated with the individual controller are forced into safe fault operation until controlled by an other controller.

Abstract: A system for accurately determining a torque current i.sub.qe for use in field oriented control of an induction motor at low rotor frequencies (e.g., about half of the motor rated frequency) which provides an ideal no load current and still enables high torque at low speed. The system includes a frequency/correction angle identifier which, based on an applied stator voltage frequency, provides a correction angle which is added to a perceived phase angle to generate a corrected phase angle which is used to calculate the torque current component i.sub.qe. The torque current component is then used by a slip calculator and an IR compensator to adjust motor operation.

Abstract: A method and apparatus for essentially eliminating turn-on delay distortions in terminal voltages and currents in a three phase motor control system wherein a compensator provides correction voltages which are added to command voltages as a function of feedback current amplitudes. Also a method for calibrating an open loop turn-on delay compensator during a commissioning procedure using a closed loop current controller.

Abstract: A system for accurately determining a slip frequency for use in controlling an induction motor. The system includes two tables for determining ideal flux and flux current levels as a function of rotor speed and uses values from those tables to determine an actual rotor inductance required for calculating the slip. The system also generates a slip multiplier which is used to increase or decrease the slip as a function of the flux current to compensate for changing rotor resistance.

Abstract: A method and/or apparatus used with a thyristor based AC-AC motor controller in a discontinuous current mode for providing power to thyristor gate drivers. The apparatus includes a snubber network and two rechargeable capacitors for storing input line voltage to an inversely connected pair of thyristors when both the thyristors are off. Stored voltage is provided via a power lead to each thyristor driver to provide power thereto and thus the circuit operates in a self-powered manner.

Abstract: A flame cannon for producing an explosion, the cannon including a tank, an effect valve, a nozzle and an ignitor, the tank coupled to a carbon dioxide source and a propane source, the tank and sources used to pressurize liquid propane therein. The nozzle forms a substantially linear and non-atomizing channel. When the effect valve between the tank and nozzle is opened, the pressurized liquid propane is forced through the nozzle and forms a liquid propane column thereabove which begins to disburse into the atmosphere wherein it is ignited to form a mushroom-shaped explosion.

Abstract: A method and/or apparatus for altering command voltages when a modulation index is greater than unity in order to maintain the linear relationship between the fundamental component of phase voltage and a sinusoidal command voltage in PWM inverter or converter usage. The method and/or apparatus calculates a command signal magnitude above which a command signal should be clamped to a peak carrier value in order to add volt-sec to an output phase voltage that are lost when the amplitude of the command signal exceeds that of a carrier signal. A modified command signal is provided which maintains said linear relationship.

Abstract: A method and/or apparatus to be used with a triangle comparison PWM controller for receiving three original reference signals and providing three modified reference signals that extend the linear relationship between the original reference sign and output voltages and reduce switching losses. A variable factor can be altered to change the form of the modified reference signals to provide various modified reference signals each of which has certain advantages. Advantageously, among other producible reference signals, one producible modified reference signal is shaped such that a resulting output voltage is identical to an output voltage that would be generated using space vector PWM controller.