Abstract: A photographic camera exposes a film to an image of an object through a lens. The camera comprises means provided with a first motor for controlling the optical characteristic of the lens through the function of the first motor, means provided with a second motor for advancing the motor through the function of the second motor, and first, second and third serial circuit means each of which is provided with a pair of serially connected switching means and which are mutually connected in parallel manner.

Abstract: In a system having a plurality of electric motors which are rated at different voltages, a voltage control circuit enables the electric motors to be connected to a common power supply. The voltage control circuit determines a first voltage appearing between the positive bus of the power supply and the motor and a second voltage appearing between the negative bus and the motor. One voltage is inverted and then summed with the non-inverted voltage to provide an average voltage. The average voltage is compared to a reference voltage and when the average voltage exceeds the reference voltage, a limit signal is generated. The limit signal is used to prevent higher voltages from being applied across the motor.

Abstract: In a DC motor driving device, upon detection of a change in the content of an input digital signal, supply of signals to switch elements from the output terminals of the decoder is suspended for a predetermined period of time following the detection of the change, and, during this predetermined period of time, the decoder's logical conversion operation is accomplished. With this arrangement, the difficulty of two series-connected switch elements being simultaneously applied with a voltage and turned on simultaneously is eliminated.

Abstract: A servo power amplifier for driving multiple DC motors (10, 12) employs a load equalization circuit (36) which allows reduction of the overall number of circuit components required to drive the motors. The load equalization circuit is coupled in parallel with each of the motor drive circuits (14, 16) across the power source (46, 48) and controls an inductive load (84) which temporarily stores energy that is returned to the power source from the motors. The equalization circuit is pulse width modulated in accordance with a control signal which is derived by sensing the current flowing through the inductive load and using a sensing circuit (44) to determine the difference in the magnitude of the positive and negative voltages supplied by the power source. The equalization control circuit and the motor drive circuits are each T-configured and employ no more than two switching elements for controlling current flow.

Abstract: An industrial robot having permanently excited three-phase motors driving each robot joint is described. Each motor is coupled to a common intermediate d-c link through an individual controlled inverter. Electric braking energy of the motors is stored in a large capacitor battery coupled to the intermediate d-c link.

Abstract: A rotating display element is provided with a display surface structure which has a plurality of display surfaces and is mounted on a rotor of a permanent magnet type stepping motor mechanism in a manner to incorporate therein the stepping motor mechanism. The display surfaces of the display surface structure are disposed side by side around the axis of the rotor. The rotor is provided with a double-pole permanent magnet member having north and south magnetic poles spaced apart a 180.degree. angular distance around the axis of the rotor. A stator of the stepping motor mechanism is provided with a first magnetic member having first and second magnetic poles disposed at 180.degree. intervals around the axis of the rotor, a second magnetic member having third and fourth magnetic poles disposed at 90.degree. intervals around the axis of the rotor, a first exciting winding wound on the first magnetic member and a second exciting winding wound o the second magnetic member.

Abstract: In order to create an economical drive unit for multiple shaft drive units for high speed loads that may be operated without wear and running noise, each drive shaft is designed as a rotor of a commutatorless direct current motor. One rotor of the unit is provided with a position sensor, all motors of the unit being connected in parallel with a commutating circuit, and all rotors being linked by a mechanical coupling of low power-transmitting capacity, such as a belt.

Abstract: A power supply in which a single variable voltage supply device is used as a power source for a plurality of motors which are simultaneously or successively rotated, in which each motor is subjected to constant current driving by a current control device connected to the motor, and in which the variable voltage supply device is controlled so as to produce a voltage which is the sum of the highest one of the voltages required for driving the motors and necessary and minimum voltage with which all the current control devices are operable.

Abstract: My invention relates to improvements in cascade cooling apparatus and to a method for maintaining a substantially safe low temperature level within an enclosure. In general, the invention is concerned with an apparatus that is designed for fail safe low temperature cascade cooling operation and specifically with preservation of biological specimen in low temperature storage. The invention incorporates a control system to continuously operate said cascade apparatus despite failure of a component therein, while maintaining a safe level of low temperature within the enclosure whose temperature is produced by said apparatus.

Abstract: A fully reclinable front seat of a vehicle in which one positioning motor controls seat back inclination, and another controls forward and back shifting of the seat, is prevented from malfunction resulting from interference with the rear seat by blocking downward movement of the seat back beyond 30.degree. until the seat has moved fully forward, and by blocking longitudinal movement of the front seat while the seat back is rising and has not yet reached 30.degree. inclination.

Abstract: A reel-to-reel constant speed tape transducer in which the torques of the reel motors are controlled to maintain the tension in the tape to the take-up reel substantially equal to or slightly greater than the tension in the tape from the supply reel. The speed of the take-up reel provides a measure of reel diameter to generate signals which control the torque of the reel motors.

Abstract: A motor driven diverter valve is provided which diverts fluid flow from a single inlet port to either one of two outlet ports, or vice versa. The valve finds general, although not exclusive, utility in solar heating systems for swimming pools, in which the valve is used selectively to divert water flow from the normal pump-filter loop of the pool installation through the solar collectors. In such an application, the diverter valve of the invention may be operated automatically in response to an electrical switching signal derived, for example, from a temperature controller in the solar heating control system, to direct the water through the solar collectors for one operating position of the valve, and to by-pass the solar collectors for a second operating position. The valve of the invention uses two synchronous permanent magnet drive motors which together consume less power than the conventional single shaded pole motor/gear box arrangement of the prior art.

Abstract: Energy conversion apparatus is disclosed to include a drive shaft, a first magnetic pole extending substantially parallel to the drive shaft and spaced radially therefrom, a second magnetic pole extending substantially parallel to the drive shaft and spaced radially therefrom, and a plurality of drive armatures each connected to the drive shaft and extending radially therefrom toward the first and second magnetic poles. The apparatus further includes control switches for sequentially energizing each of the armatures.

Abstract: An electrically operated dual motor drive system of the type having differentially variable left and right traction motor circuits (10,12) including left and right variable duty cycle power switches (20,22) connecting the motors (14,16) independently to a power source (18), left and right auxiliary switches (28,36) in series with the traction motor circuits for complemental operation of same and a selectively operated shunt switch (64) which connects the power transistors (20,22) in parallel for high torque, low speed operating conditions.

Abstract: This control device permits commanding a group of reversible motor-driven actuating devices to effect the movement of one thereof when moved mechanically. It comprises a detection circuit which detects the presence and polarity of an electromotive force at the terminals of one of the motors, and delay circuits and power circuits which are piloted by the detection circuit so as to connect the motors to a supply source with the same polarity as the polarity of the detected electromotive force.Application in the control of automobile vehicle latches.

Abstract: An electric drive system for automotive wheel rim forming equipment having inner and outer forming rolls mounted on driven spindles. The drive system includes separate drives for each forming roll and a control system for maintaining a predetermined speed ratio between the forming rolls in the absence of a working load thereon. The control system further maintains a predetermined torque ratio between the outputs of the drives for the forming rolls during the forming of a wheel rim by the forming rolls.

Abstract: An apparatus for changing the relative angles of the output shafts of a multiple-motor electric drive. For this purpose, the appropriate synchronous motor is switched to a phase-shifting frequency changer and its relative shaft (mechanical phase) angle is shifted by varying the frequency. The synchronous motor is then switched back to the operating frequency changer. The phase equality of the output voltages of the two frequency changers is monitored by signals derived from logic elements driving the frequency changers. In normal operation, the phase shifting frequency changer is driven by the same digital frequency generator as the operating frequency changer and is only switched to another frequency generator for phase shifting. Transition from one frequency changer to the other is made without shock.

Abstract: An electric drive system for automotive wheel rim forming equipment having inner and outer forming rolls mounted on driven spindles. The drive system includes separate drives for each forming roll and a control system for maintaining a predetermined speed ratio between the forming rolls in the absence of a working load thereon. The control system further maintains a predetermined torque ratio between the outputs of the drives for the forming rolls during the forming of a wheel rim by the forming rolls.

Abstract: Rotary positioning of an antenna is provided from a remote control apparatus using a first reversible motor at the antenna and a second reversible motor at the control. A rotary switch at the control is coupled mechanically and electrically to the control motor such that movement of the rotary switch energizes both the antenna and control motors, which have substantially identical speed characteristics. When the antenna has attained the desired position, the system de-energizes itself. Mechanical resistance to movement of the antenna is simulated by a feedback motor mechanically coupled to the control motor and electrically connected in series with the antenna motor. The system contemplates use of direct current motors and a two wire connection between the antenna and the remote control apparatus.

Abstract: A plurality of arbitrarily loaded induction machines are operated from a single, controlled current inverter by regulating the amplitude of inverter output current in response to the average of the individual induction machine phase angles, the machine phase angle being the phase relationship magnitude between machine air gap flux and current, and by regulating the frequency of inverter output current in response to the average of the individual induction machine phase angle and the slip frequency of the most heavily loaded induction machine. The most heavily loaded induction machine is thus assured of having sufficient flux, thereby greatly reducing the possibility of machine pull-out and resultant inverter instability.

Abstract: An arrangement of electric motors which are coupled together both mechanically and electrically comprises series pass elements and current sensing devices in the power circuits of the respective motors, each current sensing device having an output voltage which is proportional to its motor current, and which is applied to a respective linear operational amplifier having an output which controls the equivalent resistance of the series pass element (and thereby the magnitude of motor current). A single reference voltage is applied to all the linear operational amplifiers, so that, for example, if the motors are similar, each will transmit the same torque regardless of any difference in its internal impedance.

Abstract: A motor drive system for a mining shovel includes three a.c. motors which are driven by associated inverter circuits that receive power from a common d.c. bus. The d.c. bus connects to the a.c. power lines through a disconnect switch and a rectifier circuit and a chopper circuit is employed to dissipate power when the d.c. bus voltage rises due to motor regeneration. A power monitor and control circuit monitors the a.c. line voltage and the d.c. bus voltage and it controls the various system elements in such a manner as to maintain the d.c. bus voltage within an operating range. When the d.c. bus voltage cannot be maintained within the operating range, the disconnect switch is enabled to shut down the machine.

Abstract: Power control system comprising an intermittent device for applying intermittent voltage between intermittent voltage terminals; the intermittent device having a DC input terminal and at least one pair of intermittent terminals; a plurality of pairs of reverse series connected devices comprising control electrical valves and other electrical valves; said connected devices being connected in parallel between the intermittent voltage terminals; and a plurality of loads which are respectively connected to the series junctions of the plurality of pairs of reverse series connected devices.

Abstract: A drive for paper shredding or cutting apparatus having two counter-rotating cutting rollers each carrying a plurality of cutting knives, the knives of each roller being in engagement. Each roller is independently driven by an induction motor through a direct gear drive.

Abstract: This invention relates to arrangements for use in controlling the movement of a pivoted arm and it has particular, though not exclusive, application in controlling the movement of a phonograph pick-up arm.

Abstract: Static switching device for two machines making it possible to effect antkid control during drive operation and the controlling of the braking torque during brake operation. It comprises two circuits in parallel on the direct current source, a first circuit comprising, in the following order, a first chopper, a first smoothing inductance, an inductance of the first machine, a first distributing thyristor and an armature of the first machine and a second circuit comprising, in the following order, an armature of the second machine, a second distributing thyristor, a second smoothing inductance and an inductance of the second machine, the two circuits being connected together by two connections arranged on either side of the said first and second distributing thyristors, each of the connections bearing a distributing thyristor. Applications -- Controlling of electric motors used for the propulsion of vehicles.

Abstract: The electrical circuit between the power supply line and each motor or motor pair has an apparatus for re-transferring power from one mechanically driven and/or electrically braked motor to another of the motors. This apparatus includes a levelling or equalizing circuit and a plurality of back coupling devices such as diodes arranged in opposition in series. Each back coupling device electrically connects the intermediate DC circuit loosely to the levelling circuit. Upon braking of a motor, the power flows back through the associated intermediate circuit and then via the back coupling devices and levelling circuit to the other motors.

Abstract: A thyristor pulse controller in which current supply to each of a plurality of d.c. loads is controlled by respective main thyristors and a single commutating capacitor common to all the main thyristors is provided, the capacitor being connected across the main thyristors to commutate them one at a time at intervals not less than the time required to forward charge the commutating capacitor from the d.c. source and to reverse the charge on the capacitor.

Abstract: A common bus energization system is disclosed with first and second bus conductors across which a plurality of individual loads may be connected in parallel. Each of the loads is inductive and is capable of operating on direct current, for example, universal or shunt field DC motors, permanent magnet motors, magnetic particle clutches, eddy current clutches, relays, solenoids and the like. Voltage source means is provided to supply a resultant voltage to the first and second bus conductors. This voltage source means includes first and second sources with the first source connected to supply a large, positive voltage on the first conductor and the second source connected to supply a negative voltage on the first conductor. These two voltage sources are alternated with the first source effective a greater period of time for a net average polarity of positive on the first conductor. Each load, such as a motor, has a controllable semi-conductor connected to it to control the current through the motor.

Abstract: A multi-line chemical injection system for injecting chemicals into two or more independent systems including a pressure tank, a pump to supply chemicals to the pressure tank, a pressure control switch to regulate the pressure within the pressure tank and a plurality of cam operated solenoid valves to regulate chemical injection from the pressure tank.