Abstract: Beam sweeping apparatus for use in a scanning device. The apparatus comprises a mirror mounted on a pivot arm and arranged to be oscillated about an axis in an arc for sweeping a beam of light in a predetermined path. A pair of resilient are located adjacent the pivot arm to establish the limits of the excursion of the arm and mirror. A reversible electromagnetic motor is provided when energized for causing the pivot arm to move in alternate rotational directions until a portion of it engages a respective one of the bumpers, whereupon that bumper prevents further excursion of the arm in that direction and bounces the arm back in the opposite rotational direction. The energization of the electromagnetic motor is coordinated with the engagement of the bumpers by the pivot arm.

Abstract: An airless spray gun includes a pump piston and a drive arrangement formed of a coil and a swinging armature for connection to an alternating current network. A suppression circuit is provided for periodically suppressing an arbitrarily selectable whole number of successive half-waves of the alternating current. A plurality of phase control circuits corresponding in number to the number of suppression stages is also provided, each of the phase control circuits effecting a phase-angle of fixed size and being permanently connected to one of the suppression stages to supply a phase-delayed signal of selected frequency to the drive arrangement.

Abstract: An automobile fan controller comprises: a fluctuation signal generator for generating a fluctuation signal; a pulse-width-modulation circuit including a triangle generator for generating a triangle-waveform signal having a constant amplitude and a constant period, and a comparator connected to the fluctuation signal generator and the triangle generator, for comparing the fluctuation signal with the triangle-waveform signal, thereby producing a pulse signal having a pulse width variable dependent on the fluctuation signal; and a driver circuit, including a switching power transistor connected to the pulse-width-modulation circuit, a fan motor mounted on an automobile, and an air flow switching unit mounted on the automobile for energizing and de-energizing said fan motor with a variable pulse width in response to the pulse signal.

Abstract: A vibrator control circuit is provided for controlling the driving current supplied to the driving coil of an electromagnetic vibrator for a bed or the like. The control circuit is adapted to be connected to source of A.C. line voltage such as a standard wall outlet and controls the duration of the portion of each cycle of the A.C. line voltage supplied to the vibrator. The control circuit includes an electronic switch, e.g., a transistor, connected in series with the driving coil of the vibrator and a control pulse generator for supplying control pulses to the electronic switch to control switching of the electronic switch in timed relationship with respect to the A.C. line voltage waveform so as to gradually vary the duration of the portion of the A.C. line voltage supplied to the electromagnetic vibrator during each cycle of the A.C. line voltage.

Abstract: A blocking oscillator for a reciprocating electromagnetic actuator having a solenoid coil, a detection coil for generating a control signal in response to a charge in the magnetic field generated by the solenoid coil, a silicon Darlington amplifier responsive to the control signal to control the current through said solenoid coil, and a diode connected in series with the collector of the Darlington amplifier rendering the Darlington amplifier immune to reverse voltage and transient signals.

Abstract: A vibrating armature motor, which includes a voltage source, an armature, an electromagnet having at least one exciter coil disposed adjacent the armature, a spring for rotationally biasing the armature, a sensor element for sensing the rotational velocity of the armature and for generating a signal proportional to the sensed velocity, a variable duty cycle pulse generator for generating a stream of triggering pulses, the duty cycle of the triggering pulses being dependent upon the sensor signal, and an electronic switch for controlling the current flow from the voltage source through the exciter coil in response to the triggering pulses.

Abstract: The invention deals with a method and a circuit for operating a spray gun having a vibrating armature drive which is energized with an electrical a.c. signal. To reduce the liquid which is sprayed per unit of time by the spray gun, a pulse width modulated energizing signal with abruptly rising leading edges is fed to the vibrating armature drive. The circuit includes a control circuit which produces a control signal with abruptly rising leading edges and a controllable switch which electrically couples a supply voltage source and the vibrating armature drive, the control terminal of the switch being connected to the output of the control circuit. The circuit may alternatively have a signal generator which produces a control signal with abruptly rising leading edges and a power amplifier connected to the output of the signal generator, the output of the power amplifier being connected to the vibrating armature drive.

Abstract: A gas flow rate control system designed to control the gas flow rate by continuously controlling the opening of an electromagnetic valve, wherein the magnetic hysteresis of a plunger and a yoke which are magnetic material forming the magnetic circuit is removed by alternately passing current pulses through two energizing coils, so as to continuously reverse the direction of magnetization of the magnetic circuit and wherein the static friction between the plunger and the yoke is removed by oscillating the plunger.

Abstract: Circuitry is disclosed for driving the transducer assembly of a dental handpiece at its resonant frequency. The circuitry includes a variable frequency oscillator and a peak-detecting processor which allows the oscillator to sweep through a continuum of frequencies until maximum current in the transducer driving coil is sensed.

Abstract: A method of, and apparatus for, energizing electromagnetic vibrators. An electromagnetic vibrator, driven by an electromagnet, is energized directly from an electric mains supply line carrying alternating current at a particular frequency. The electromagnet is operated at a fraction greater than one-quarter, and preferably equal to two-thirds or two-fifths, of the supply frequency such that the current drawn from the mains supply is substantially alternating current.

Abstract: An oscillating-armature electric motor comprises an armature which, during operation of the motor, moves along a path of oscillatory movement that includes a substantial range of movement in which the armature poles are located remote from the stator poles. When the poles are remote from each other, the efficiency of electrical to mechanical energy conversion would be low. The stator winding is energized in dependence upon the position of the motor, to avoid wasteful electrical energy dissipation during that part of the armature swing in which the aforementioned efficiency would be low. During the part of the armature swing in which the efficiency is high, the energization is great enough to establish a range of armature movement which goes beyond the high-efficiency armature positions to predominantly comprise low-efficiency armature positions.

Abstract: A method is provided for adjusting to an original predetermined value the natural frequency of the carrier load of a processor controlled stepper motor driving said carrier through a belt and pulley arrangement. The adjustment is performed by having the microprocessor move said carrier back and forth repetitively, at a rate based on the original natural frequency value and by adjusting the belt tension for obtaining maximum amplitude vibrations of the carrier load.

Abstract: A control circuit for an electromagnetic cutting apparatus includes auxiliary power impulse systems and auxiliary condensers for accelerating an already moving plunger of the cutting apparatus. The basic control circuit includes photoelectric sensors for sensing the leading and trailing edges of components. The sensors are part of an electronic circuit for rapidly charging a coil surrounding a core on the plunger for driving a blade downwardly to cut the tape. Condensers in the electronic circuit are normally charged and, in response to signals from the photoelectric sensors, instantaneously discharge into the coil to actuate the plunger. The auxiliary power impulse systems and auxiliary condensers are controlled by timers for discharging the auxiliary condensers into the coil a short time after the condensers of the basic circuit and while the plunger is moving to accelerate the latter.

Abstract: A vibrator motor is coupled to the frame of a body support structure to vibrate the latter. The motor is energized by a train of triangular pulses modulated by a triangular pulse signal having a lower frequency than that of the triangular pulse train.

Abstract: A step motor in a horological device is connected in a control circuit such that the motor is fed by a battery under the control of a reference oscillator, a frequency divider, a power stage and a shaper. The power stage comprises MOS power transistors exclusively of N-MOS type connected in pairs such that one transistor has its emitter connected to one terminal of the battery and its collector connected to one terminal of the motor coil and to the emitter of the second transistor, whereas the second transistor has a collector connected to the other terminal of the battery. The shaper delivers voltage to the power transistors via a voltage booster in the form of a capacitor so that the control pulses are of a voltage much higher than the voltage of the battery itself. When the motor is of bi-polar type a second pair of power transistors is connected to the other terminal of the coil in similar fashion.

Abstract: A switching system for a solenoid reciprocator motor of a type which has a piston arranged to reciprocate into and out of a solenoid. The switch is an SCR rectifier and the trigger lead to close the switch is pulsed by a commutator operating in unison with the movement of the solenoid or a shaft rotated by the solenoid. The energizing cycle when the SCR switch is closed is terminated by a disconnect lead which is pulsed responsive to a subsequent contact of the circuit by the commutator. A preferred mode of pulsing the disconnect circuit is to associate the disconnect circuit with another solenoid of the motor whereby the first solenoid is turned off when the other solenoid is turned on by the commutator.

Abstract: A method and apparatus for removing surplus ink from the surface of rotogravure printing cylinders by providing a doctor blade apparatus having an edge adjacent to but spaced from the surface of a rotating printing cylinder. The printing cylinder carries surplus ink and the doctor blade apparatus is disposed at some angle .alpha. with respect to a tangent to the printing cylinder and functions to remove all but a residual portion of the ink on the printing cylinder. To achieve this, the doctor blade is oscillated at a frequency sufficient to create a hydrodynamic barrier in the ink layer. This hydrodynamic barrier or turbulence in the ink layer at the doctor blade apparatus serves as a barrier for blocking passage of all but a predetermined desired residual portion of the ink layer past the oscillating edge of the doctor blade apparatus. The doctor blade apparatus can take many forms and can be oscillated in any desired manner.

Abstract: A vibrator motor is coupled to the frame of a body support structure to vibrate the latter. The motor is energized by a train of triangular pulses modulated by a triangular pulse signal having a lower frequency than that of the triangular pulse train.