Abstract: A flux-gate magnetometer torque sensor is provided having a rotatable shaft to which a torque force is to be applied, a sleeve of conductive foil affixed to the surface of the shaft over the magnetically active regions, a plurality of saturable magnetic wires or strips mounted to the rotatable shaft and parallel to an axis of rotation, sensor circuitry containing an oscillator for generating a signal, a divider coupled to the oscillator for dividing the frequency of the signal by two, a first and second coil each surrounding a different section of the rotatable shaft and having an input coupled to the divider output, a multiplier having inputs coupled to outputs of the first coil, the second coil, and the oscillator, and an integrator having an input coupled to the multiplier output and an output coupled to both outputs of the first and second coils, wherein the output voltage of the integrator corresponds to the torque being applied to the rotatable shaft.

Abstract: An impact tool control method and apparatus and an impact tool using the same. Pulses of torque applied to a fastener by the impact tool are measured. The duration and magnitude of the torque pulse are subtracted from a torque signal and the resulting difference is integrated over time to obtain a fastener angular velocity signal. The angular velocity signal is integrated over time to obtain a displacement signal which can be converted to a torque signal. The impact tool can be controlled based on the value of the torque signal.

Abstract: An impact tool control method and apparatus and an impact tool using the same. Pulses of torque applied to a fastener by the impact tool are measured. The duration and magnitude of the torque pulse are subtracted from a torque signal and the resulting difference is integrated over time to obtain a fastener angular velocity signal. The angular velocity signal is integrated over time to obtain a displacement signal which can be converted to a torque signal. The impact tool can be controlled based on the value of the torque signal.

Abstract: An impact tool control method and apparatus and an impact tool using the same. Pulses of torque applied to a fastener by the impact tool are measured. The duration and magnitude of the torque pulse are subtracted from a torque signal and the resulting difference is integrated over time to obtain a fastener angular velocity signal. The angular velocity signal is integrated over time to obtain a displacement signal which can be converted to a torque signal. The impact tool can be controlled based on the value of the torque signal.

Abstract: A flux-gate magnetometer torque sensor is provided having a rotatable shaft to which a torque force is to be applied, a sleeve of conductive foil affixed to the surface of the shaft over the magnetically active regions, a plurality of saturable magnetic wires or strips mounted to the rotatable shaft and parallel to an axis of rotation, sensor circuitry containing an oscillator for generating a signal, a divider coupled to the oscillator for dividing the frequency of the signal by two, a first and second coil each surrounding a different section of the rotatable shaft and having an input coupled to the divider output, a multiplier having inputs coupled to outputs of the first coil, the second coil, and the oscillator, and an integrator having an input coupled to the multiplier output and an output coupled to both outputs of the first and second coils, wherein the output voltage of the integrator corresponds to the torque being applied to the rotatable shaft.

Abstract: An impact tool control method and apparatus and an impact tool using the same. Pulses of torque applied to a fastener by the impact tool are measured. The duration and magnitude of the torque pulse are subtracted from a torque signal and the resulting difference is integrated over time to obtain a fastener angular velocity signal. The angular velocity signal is integrated over time to obtain a displacement signal which can be converted to a torque signal. The impact tool can be controlled based on the value of the torque signal.

Abstract: A magnetoelastic load cell for providing an output signal indicative of a force applied to the load cell comprises a magnetoelastically active, ferromagnetic, magnetostrictive disk-shaped member having upper and lower surfaces and comprising a central hub, an annular rim and at least two slots formed therebetween for defining at least two generally spiral-shaped spokes extending between the upper and lower surfaces, each of the spokes traversing approximately 360° between its origin at the hub and its termination at the rim. The spokes are magnetically polarized in a single circumferential direction and possess sufficient magnetic anisotropy to return the magnetization in the spokes, following the application of a force to the load cell, to the single circumferential direction when the applied force is reduced to zero. Magnetic field sensor means are mounted proximate to the member to sense the magnitude of the magnetic field produced by the member in response to the applied force.

Abstract: A flux gate inductor responsive to an external magnetic field produced by a rotating magnetoelastic sleeve and oscillating voltage applied to the flux gate inductor induces a field in the flux gate inductor, for inducing current flow through the flux gate inductor, which flows through a shunting resistor, creating a voltage which is triangular as a result of the inductance of the flux gate. The sum of the induced and external fields exceeds the saturation flux density of the flux gate, causing the flux gate inductance to zero. This results in a rise in the current through the flux gate inductor and a voltage spike across the shunt resistor. The spike is detected for causing a change in an inverter for producing the oscillation voltage. Meanwhile, the external magnetic field causes an asymmetry between positive, negative currents required to saturate the flux gate inductor. This asymmetry results in a departure of the oscillation voltage from a 50% duty cycle.

Abstract: A capacitive rotary position sensor is provided. The rotary positions sensor includes a housing, a stator, and a rotor. The stator is formed of a disc shaped piece of insulating material including a plurality of conductive plates formed in a circular pattern on the surface of the disc. Similarly, the rotor is formed as a second disc of insulating material having a single conductive plate formed on the surface thereof. A signal generator provides a polyphase signal for driving each of the conductive plates formed on the rotor with an individual component of the polyphase signal. The stator and rotor are placed in parallel to the stator disc, and the plurality of conductive plates on the stator face the single conductive plate formed on the rotor. A thin dielectric coating applied to the rotor plate prevents the rotor conductive plate from shorting the adjacent stator conductive plates.

Abstract: A Micro-Powered Flux-Gate Magnetometer is provided for measuring the strength and direction of external magnetic fields. The magnetometer includes a saturable core inductor, or flux-gate positioned in an area where the magnetic flux due to external magnetic fields will enter the inductor core and alter the inductance of the coil. The flux-gate inductor is driven by an alternating input signal sufficient to magnetically saturate the inductor core during each cycle. A saturation detecting circuit determines when the flux-gate core reaches saturation, and provides an saturation output signal indicating when, relative to the input signal, the core reaches saturation on each cycle of the input waveform. A comparison circuit compares the saturation signal and the alternating input signal and measures a propagation delay through the flux-gate inductor. Finally, an output circuit provides an analog output voltage signal proportional to the propagation delay through the flux-gate inductor.

Abstract: A pulse step modulator includes a plurality of N series connected unit step modules each including a DC voltage source having a value V. A plurality of M series connected binary step modules are connected together in series with the series connected unit step modules with each binary step module including a DC voltage source having a value which is a fraction of V. Each module has an associated actuatable switch means for, when actuated, turning on the associated module to provide a step voltage. An output circuit connected to the series connected modules for providing an output voltage to a load wherein the magnitude of the output voltage is equal to the sum of all of the voltage sources of the modules that are turned on. An analog input signal is converted into digital words, each word including first and second multi-bit digital portions.

Abstract: A pulse step modulator (PSM) is presented herein for use in an AM transmitter. The modulator includes a plurality of unit step modules connected together in series with each module including a DC voltage source together with an associated actuatable switch for, when actuated, turning on the associated module to provide a unit step voltage. An output circuit is connected to the series connected modules for providing an output voltage to a load wherein the magnitude of the output voltage is equal to the sum of all of the voltage sources of the modules that are turned on. A plurality of module turn on signals are provided with each turn on signal serving to actuate one of the switches in one of the modules with the number of turn on signals being provided being dependent upon the magnitude of an input signal.

Abstract: A highly efficient, tuned, switching power amplifier has components in a circuit configuration which minimizes switching losses and stored energy within the circuit. The circuit includes a pair of switches operating at the carrier frequency at substantially 50% duty. The switches are coupled through a transformer to a load, with the circuit being tuned, taking the particular load into account, so as to minimize the power loss in the switches by ensuring that immediately prior to, and during each, transition of each switch from its non-conducting (off) state to its conducting (on) state, both the voltage across the switch and the first derivative with respect to time of the voltage across the switch are substantially zero.

Abstract: A drive circuit generates a quasi-square wave for use in switching power amplifiers by supplying square wave signals which are 180.degree. out of phase, but otherwise identical, to the respective control inputs of two switching transistors. Opposite ends of the respective controlled paths of the transistors are connected to the input of the device which is being driven. The driven device input has a capacitance associated therewith, which normally results in a voltage loss as this capacitance is alternately charged and discharged. The circuit component values are selected so that this capacitance is charged while the switching transistors have yet to reach their threshold voltages, and thus at the moment when either transistor is switched to a conducting state the voltage across that transistors controlled path will be substantially zero, and the normal switching loss, which is a product of the square of that voltage, the input capacitance of the driven device, and the operating frequency, is eliminated.

Abstract: A combining circuit for Class-E RF power amplifiers includes a transformer for each power amplifier to be combined, the respective secondaries of the transformers being connected in series to the RF load of the system. Each of the transformers further has a tertiary winding, with one end connected to a first common circuit node, and the other end being connected to a second common circuit node via an inductance. A switchable reactive network is connected to the second common circuit node, and in the event that one of the power amplifiers is removed from the circuit, such as due to failure thereof, the primary terminating impedance of the transformer connected thereto will become a high impedance, and by appropriate switching of the reactive network, in combination with the remaining circuit components, the matching impedance necessary to maintain optimum operation of the remaining power amplifiers is achieved, with a benign VSWR being presented to the remaining power amplifiers.

Abstract: A switching power amplifier including a full bridge rectifier 10 having switches 20, 22, 24, 26, 30 and 32 connected on either side of the full bridge rectifier 10, provided to produce a five level waveform synthesis. Auxiliary switches 30 and 32 allow each half of the full bridge 10 to switch between three distinct voltage levels. Therefore, the third and fifth harmonics are eliminated, and further, the remaining harmonics are greatly suppressed. MOSFETs, bipolar transistors, vacuum tubes, etc., can be employed for the switches 20, 22, 24, 26, 30 and 32 depending upon the application of the circuit.