Abstract: An electrical switch comprises a pair of spaced terminals, fixed in an insulating housing; a metal roller; and, a finger-piece for moving the roller between first and second switching positions engaging only one and both terminals respectively. The one terminal is resiliently flexed to bias the roller against the second terminal in the second switching position. The one terminal comprises a cantilever spring having an upset end protruding into the roller path and providing the fulcrum for an overcenter action biassing the roller in either switching position.

Abstract: A motor drive apparatus includes a two-phase synchronous motor having two power windings. The motor is supplied with power from an alternating voltage network through a direct convertor. The converter has two controllable converter bridges that are supplied with power by the network. Each power winding of the motor is connected between a DC terminal of one bridge and a DC terminal of the other bridge. The power windings have center taps that are connected.

Abstract: A control system regulates operation of an electrical motor having multiple stator and rotor coils by regulating the phase displacement (1) between the rotor and stator energizing signals, (2) between the signals passed to the individual rotor coils, and (3) between the signals passed to the individual stator coils. A recorder coupled to the lines over which the phase-regulating signals are supplied to the rotor and stator coils can record these signals for later application to the motor to repeat the initial movement. Additionally displacement of the motor shaft produces signals which can be recorded for later duplication of the original shaft displacement. The phase-regulating signals for the rotor and stator coils can be supplied from a variable frequency oscillator, or a data processor, or any other suitable source.

Abstract: A refrigerant compressor of the type driven by a single phase motor capable of operating at a low speed and a high speed. The motor, including four separate windings, a first set of high-speed two-pole auxiliary and main windings, and a second set of low-speed four-pole auxiliary and main windings all wound on the same stator core. Each set of windings is provided with independent line break protectors that enable each set of windings and protector to be optimized without affecting the other. A mandatory low-speed start system is incorporated that insures initial low-speed start even when conditions require high speed operation. Speed switching from one speed to the other is accomplished in the present system while the motor is running without causing interruption of compressor operation.

Abstract: A keyboard type switch is disclosed wherein a domed snap disc performs triatic functions of acting as a tactile feedback source for switch operation, of supplying a conductive path for electrical energy when depressed, and of providing a contact surface for manual operation. The disclosed switch is covered by a multilayered nonconductive membrane and spacer to provide maximum safety from electrical shock to the operator.

Abstract: This invention relates to a switching arrangement for use in stopping or reversing an electrically driven roller door when an object lying in its path is struck during closing. The arrangement comprises a switch bar extending the width of the door curtain and projecting below its bottom edge, hinge mounting means securing the bar to the curtain and permitting swing movement about a horizontal axis, resilient loading means urging the bar into a rest position in which the lowermost bar surface is laterally displaced from the axis and a switch actuated by movement of the bar from its rest position.

Abstract: A circuit arrangement for the driving and for independent recuperation braking of a vehicle provided with DC compound traction motors, a DC feeding circuit, and pulse control for obtaining braking with so-called clean recuperation. The series windings of the motors and their armatures are connected to a tetragonal circuit with four terminals, with a pulse converter controlling the armature voltage of the motors.

Abstract: An external operation device for electronic timepieces having a switch unit made up of an array of a plurality of electric switches is inserted in an external member of a timepiece and said electric switches being electrically connected to an internal module.

Abstract: To achieve synchronization of an inverter-synchronous machine drive system, feedback of a phase angle signal, derived in part from stator current drawn by, and voltage supplied to, the synchronous machine, is provided to control the frequency of inverter thyristor conduction. At light or zero synchronous machine load conditions, machine stator current may be of insufficient magnitude to permit derivation of the phase angle feedback signal; therefore, substitute simulated stator current signals, proportional to a preselected combination of inverter thyristor gating pulses, are utilized to derive the phase angle feedback signal, thereby allowing inverter-synchronous machine drive synchronism to be maintained.

Abstract: In an inverter-synchronous machine drive system subject to operator control, feedback control is employed to synchronize machine-inverter operation. A phase angle command signal, responsive to a fixed value phase angle signal during initial machine excitation and alternately responsive to machine load variation as controlled by an operator command, is generated and compared against the actual machine phase angle difference between machine phase current and air gap flux. A frequency command signal, responsive to the angle difference therebetween, is impressed on the inverter to vary machine excitation responsive to the magnitude of the phase angle difference.

Abstract: An improved four-way switch operated by a single manual push button at the end of a control column includes an axially extending shaft mounted to pivot on a stud. The shaft and stud are retained within a housing. An elastomeric washer with a frusto-conically shaped center passage is affixed on the shaft and engages the housing to radially bias the shaft and thereby maintain the shaft in proper axial alignment. Contacts are attached to the shaft and engage selected contacts on the housing when the shaft is pivoted. Guide slots in the housing cooperate with the pivotal shaft to control the direction of pivotal movement of the shaft.

Abstract: Apparatus for controlling parallel connected unequal electrical loads, such as the speeds of a two speed motor, from a two wire branch circuit having one leg load connected through a single pole, single throw switch, utilizing the unbalanced characteristics of the different loads, such as the high and low speed windings of a two speed split phase motor after the start winding circuit is broken, to control multiple solid state static switches coupled through a flip-flop for sequentially controlling the loads.

Abstract: Control systems for starting and synchronously driving gyroscope rotors establish magnetic polarization of the rotor ring prior to start-up and then accelerating the magnetic field vector as the rotor accelerates to its normal operating speed.

Abstract: In a control system of an AC motor fed from a frequency converter including a thyristor rectifier and a thyristor inverter, the speed of the motor is controlled by a current control system comprising a speed control circuit responsive to a reference speed signal and an actual speed signal, and a current control circuit which produces a pulse signal supplied to the rectifier. The inverter is controlled by another pulse signal corresponding to the angular position of the rotor of the motor. An additional current instruction circuit is provided which in response to the two pulse signals described above controls the current control circuit.

Abstract: An improved current supply apparatus for the power windings of a synchronous machine wherein a first center tap of a first power winding is connected to one side of a current source and a second center tap of a second power winding is connected to the other side of the current source. The respective ends of the power windings are connected by thyristors that are ignited at times determined by the angular position of a rotor of the synchronous machine. Each thyristor is ignited to conduct current during one-fourth of a power supply cycle to generate an output current of changing polarity that is applied to the power windings to drive the synchronous machine.