Abstract: According to a preferred embodiment of the present invention, a double-ended moving coil linear actuator is provided comprising a cylindrical core and a hollow shell disposed around the core to define an annular space between the inner wall of the shell and the outer wall of the core. A non-magnetic spacer is mounted in the annular space to divide the annular space into first and second annular cavities, each of the cavities having a closed end adjacent the spacer and an open end. A first set of magnets is mounted within the first annular cavity to define a first magnetic circuit. A second set of magnets is mounted within the second annular cavity to define a second magnetic circuit. The magnets of these two magnetic circuits are sized and arranged to define a third "interleaved" magnetic circuit which is created by the interaction of the first two circuits. Each of the first two magnetic circuits has a dual-winding coil assembly associated with it.

Abstract: A low height-profile rotary optical encoder having an improved coupling structure for coupling the code disc to the shaft for which positional information is desired wherein the coupling structure includes a coupling member having a shaft portion and an integral flexible coupling portion, a bearing structure for rotatably supporting the shaft portion within the encoder, the bearing structure and shaft portion each having a length which is substantially equal to one another, and the height of the encoder optics can be greater than the height of the bearing structure, and a base which is adapted to support the bearing structure, the shaft portion of the coupling member and the encoder optics in a common transverse section of the encoder and to house the flexible coupling portion of the coupling member wholly within the base.

Abstract: An apparatus for use with a multi-phase brushless DC motor which is driven by signals from a motor controller/driver device, in which power supplied to the motor controller/driver device is routed through a bridge rectifier circuit so that the proper polarity of voltage is supplied to the motor controller/driver device, and also including a circuit connected between a power lead to the motor controller/driver device and input terminal of the bridge rectifier circuit so that a forward/reverse control signal is generated and can be applied to the motor controller/driver to control the direction of rotation of the motor as a function of the polarity of the power supplied to the bridge rectifier circuit.

Abstract: A linear electromechanical actuator having a variable drive force. The actuator includes a moving coil which moves along a stroke path in response to an input current. A magnetic circuit provides a magnetic flux through which the coil is driven. The flux density along the stroke path is non-uniform, with a higher flux density being present only in that region of the stroke path where a higher actuator drive force is required. Thus, less expensive magnetic material can be used. Since the overall flux density in the magnetic circuit is reduced, the dimensions of the soft iron elements of the magnetic circuit can be reduced without magnetic saturation so as to further reduce construction costs.

Abstract: An encoder for providing positional information about a moveable member comprising code member means couplable to the moveable member for movement with the moveable member, reference means positioned to be stationary relative to the code member, an index sequence positioned on the code member, a mask sequence positioned on the reference member means, and means for detecting the degree of registration between the index sequence and the mask sequence, wherein the index sequence and the mask sequence include a plurality of building block patterns that are separated by predetermined spacings.

Abstract: An improved apparatus for generating an index signal in incremental encoders, wherein an index sequence of code elements is provided on the code disc, and the degree of registration between the index sequence and a mask sequence is detected, and further wherein the mask sequence and index sequence are configured so that there is maximum registration of the elements between the index sequence and mask sequence for the index position of the code disc and the degree of registration for all other angular positions of the code disc is at or below a predetermined background registration level, and so that the degree of registration for angular positions adjacent to the index or zero reference position is greater than zero and preferably no greater than the background registration level.

Abstract: A digital time fuze for providing an output pulse following a precise, specified time interval, wherein control means extract time interval data from a set signal, the control means thereafter providing a portion of a clock signal to a counter such that the length of the portion of the clock signal provided is determined by the time interval data. Counter means count the number of pulses in the clock signal portion to accumulate a timer count. In response to a start signal, the counter means counts down the timer count according to a count down clock which is provided by the control means and which is proportional to and derived from the clock signal. When the count reaches zero the output pulse is provided.

Abstract: A power saving regulated light source circuit, comprising a light emitting diode (LED), a direct current source and a switching transistor connected in series with the LED, a control voltage producing resistor connected in series with the LED to produce a control voltage corresponding to the current through the LED, a storage capacitor connected in parallel with the series combination of the LED and the resistor, a comparator having its output connected to the input of the transistor, the comparator having a reference input and a control input, a stabilized biasing source for supplying a stabilized reference voltage to the reference input, the control input of the comparator being connected to the control voltage producing resistor, the comparator having a high output state when the reference voltage exceeds the control voltage while having a low output state when the control voltage exceeds the reference voltage, the transistor being conductive in response to the high state while being nonconductive in respo

Abstract: An encoder for producing multidigit code word signals corresponding to the position and movement of a shaft or some other movable member, comprising a housing, a photocell board or some other signal producing board mounted on the housing and having photocell means or some other signal producing means including a multiplicity of signal channels for supplying a multiplicity of electrical signals indicating the position and movement of the code member, a plurality of circuit boards mounted on the housing in stacked relation to the signal producing board, the circuit boards including means for processing the signals from the signal producing means, and a multiplicity of sockets and pins mounted on the boards and plugged into one another for establishing electrical connections between the successive boards.

Abstract: An encoder system which provides non-power of two, unambiguous, even counts, the system having a modular configuration to permit a substantial portion of the system to comprise standardized modules, wherein modifications to a minimum of modules provide a wide range of different system counts, the system utilizing a truncated, symmetric, unit step code sequence and a division of processing functions among modules which permits the user to select among system outputs having a number of different processing levels.

Abstract: An optical system for an optical encoder of the type having an optical code disc with a plurality of code tracks, and a multichannel photodetector for receiving modulated light from the code tracks, the optical system comprising a light source for producing a line of light, an optional collimating lens for receiving divergent rays of light from said light source and for directing the light in generally parallel rays toward the code disc, an objective lens disposed between the collimating lens and the code disc for focussing the light in a sharp line on the code disc, a housing for supporting the collimating lens and having a seat for receiving the objective lens, an aperture plate having an aperture slit therein aligned with the objective lens, and means for holding the aperture plate on the housing with the objective lens retained between the seat and the plate.

Abstract: A shaft angle encoder for producing a multiplicity of output signals corresponding to a multidigit binary code word representing the angular position of the shaft, comprising a rotatable code member having a multiplicity of code tracks ranging in order from zero to n except for the omission of a skipped track having the order of n minus 1, the track of zero order having the largest divisions while the track of the order n has the finest divisions, transducer means for reading the tracks and producing corresponding electrical signals, a parity detector having inputs for receiving the electrical signals corresponding to the tracks having the orders of zero through n minus 2 and for producing a corresponding even/odd output, and an exclusive OR logic gate having inputs for receiving the even/odd output of said parity detector and the electrical signal corresponding to the track of the order n, the exclusive OR gate producing an output which synthesizes the electrical output signals corresponding to the skipped t

Abstract: A multidigit fiber optic encoder having only one or two fiber optic cables between an active zone containing a light source and photodetectors, and a passive zone containing a multidigit code member having a multitude of code tracks. First and second sets of color filters are associated with the code tracks and the photodetectors, so that each code track modulates light of a different color, which is transmitted to only the corresponding photodetector. The light beams of the different colors are combined for transmission between the passive and active zones. A single fiber optic cable may be employed between the active and passive zones for transmitting light in both directions, by providing first and second beam splitters at the active and passive ends of the cable to split the transmitted and received light. Alternatively, two fiber optic cables may be employed to transmit light in the opposite directions, to obviate any need for the beam splitters.

Abstract: A frequency multiplying circuit for producing double frequency sine and cosine output signals sin 2x and cos 2x from sine and cosine input signals sin x and cos x, comprising two multiplier circuits, each having an output e.sub.0 and four inputs a.sub.1, a.sub.2, b.sub.1 and b.sub.2 and being adapted to perform multiplication in accordance with the following relation:e.sub.0 =K(a.sub.1 -a.sub.2)(b.sub.1 -b.sub.2);sine and cosine input amplifiers for supplying the sin x and cos x input signals; means for supplying the cos x input signal to the a.sub.1 input of the first multiplier circuit; means for supplying the cos x signal to the b.sub.1 input of the first multiplier circuit, means affording a gain of 2 in the first channel, relative to the second channel, means for supplying zero input to the a.sub.2 and b.sub.2 inputs of the first multiplier circuit; means for supplying the cos x input signal to the a.sub.1 and b.sub.

Abstract: The disclosed fin and nozzle unit comprises a generally cylindrical nozzle body having an axial nozzle opening therein for discharging a gaseous propulsion stream, a plurality of fins having pivot means mounting such fins on a rear end portion of the nozzle body for swinging movement between retracted launch positions and extended flight positions in which such fins are swung outwardly from the launch positions through a predetermined angle, such fins having bent or skewed portions which are positioned in the gaseous propulsion stream when the fins are in their retracted launch positions for causing the gaseous propulsion stream to act upon the bent portions so as to produce spinning movement of the rocket when it is being launched, the bent portions being movable outwardly out of the gaseous propulsion stream when the fins are swung outwardly into their extended flight positions to avoid imparting further spin to the rocket during flight.

Abstract: Input tone signals are supplied to a square wave generator for producing square wave output signals corresponding to the tone signals. The square wave generator includes an operational amplifier having a tone signal input and a control signal input for receiving a first control voltage for activating the amplifier and a second control voltage for squelching the amplifier. The control voltages are produced by squelch control voltage generating means for receiving the input tone signals and producing the first control voltage when the tone signals exceed a predetermined level, while producing the second control voltage when the input tone signals are less than such predetermined level.

Abstract: The relative transverse velocity between a local station and a zone of reference or observation is measured by providing first and second directional radiation receiving devices at the local station, such devices being aimed along parallel paths extending to the zone of reference. Such paths are spaced apart by a predetermined transverse distance. The first and second radiation receiving means include respective first and second converting means for converting the received radiation into first and second electrical signals. Any transversely moving radiation feature produces corresponding signal features in such first and second signals, such signal features being staggered with respect to time. The lapse of time between such staggered signal features is determined by time lapse measuring means. The velocity of such transverse movement is inversely proportional to such time lapse.

Abstract: Light is modulated by an optical code member having first and second parallel tracks, each with alternate segments of different optical characteristics, such as optical reflectivity. The different segments are staggered between the parallel tracks. The modulated light is transmitted along first and second fiber optic elements from the first and second tracks to respective first and second photoelectric sensors having a common substrate to produce push-pull electrical outputs from said sensors. The light may be supplied to the first and second tracks by respective third and fourth fiber optic elements, which may extend from a common light source. The third and fourth fiber optic elements may have light supplying ends which are closely adjacent the light receiving ends of the first and second fiber optic elements.

Abstract: The ammunition firing system is especially advantageous for electrically firing military rockets from a multiple tube rocket launcher. The system provides an electrical signal indicating the presence or absence of a rocket ready to be fired in each launching tube. The signal is derived from the firing wire or lead which is also used to fire the rocket. In each rocket, an igniter of low electrical resistance is connected between the firing lead and a common ground. Initially, the firing lead is connected by switching means to a signal source which supplies a signal current of a low energy, insufficient to cause the igniter to fire the ammunition. The system includes indicating means for indicating the presence or absence of the signal current through the igniter, so as thereby to indicate the presence or absence of the rocket in the launching tube.

Abstract: The system for electrically identifying and firing ammunition is especially advantageous for firing military rockets from a multiple tube rocket launcher. The system provides an electrical signal for initially identifying the type of rocket or other ammunition loaded and ready to fire in each launching tube. The identifying signal is derived from the firing wire or lead which is also used to fire the rocket. In each rocket an igniter and a diode rectifier are connected in series in the firing circuit which usually extends between the firing lead and a common ground. The diode rectifier is polarized to conduct the firing current while being nonconductive as to the signal current which is oppositely polarized. Each rocket includes an identification impedance having a nature to identify the type of rocket. The different types of rockets have measurably different identification impedances.