Abstract: A shut-down and first-out annunciator device comprising sensor switches that change condition when a fault occurs. Logic and display circuits provide a digital readout indicative of a fault condition. Shut-down means are responsive to a shut-down signal produced by the logic circuit and produce a latching signal for the display. A first power supply powers all sections during normal operation and a second power supply powers the display and shut-down circuits after shut-down.

Abstract: A two terminal timed electric switch which connects in series with but one side of a power carrying a.c. circuit. In particular the timer serves as an effective replacement for the ubiquitous wall-switch type of on and off device used in the construction trades, as in houses, business buildings, and the like. An advantage is that when used as a replacement for an ordinary switch, the timer serves to achieve significant energy savings by turning forgotten lights off when not needed. The timer functions as a delayed-off switch; that is to say the switch and the load are turned on by manual actuation, but turn-off does not occur until some finite time period has elapsed. The timed switch employs all electronic timing elements, e.g. no motors or thermal timing elements or the like.

Abstract: A magnetically actuatable tamper switch assembly comprising a housing of nonmagnetizable material as elongated in a longitudinal direction, wherein a plunger is operable to be longitudinally moved through an aperture in the first end of said housing, wherein the improvement comprises substituting the mechanical wiper contacts of prior art tamper designs with an elongated bar magnet and associated elongated reed switch set of components. The present invention uniquely takes advantage of both the interior housing space available in the conventional tamper switch housing and also the reaction of an overlapping reed switch region to the lines of flux which eminate from a given pole of a magnet material.

Abstract: Method and apparatus for simultaneously teaching a plurality of students how to play a musical instrument including programmed audio-visual instruction by pre-recorded audio inputs, prearranged note combinations displayed on a student light strip, confirmation of right or wrong answers on periodic quiz questions, sequential pictures projected on a screen, and correlated printed lesson materials, which programmed instruction may be stopped by the teacher in order to selectively instruct certain students by broadcasting oral instructions, and by playing a master keyboard which activates the student light strip. A teacher's console is provided for collectively monitoring the student quiz results, and for selectively listening to individual student musical performances during the programmed instruction period.

Abstract: A system adapted to be coupled to the alternator-rectifier system of a motor vehicle including a feedback capacitor coupled from the stator windings to the rotary coil for applying a pulsating DC output to the rotary coil when a welding load is applied to the output of the alternator-rectifier system. A DC power supply is employed normally to excite the rotary coil during no-load conditions.

Abstract: A magnetically controlled switching device having a magnetic shunt plate with many terminals arrayed along the peripheral portions thereof, a plurality of coil forms located at the crosspoints of a matrix consisting of X and Y coordinates on a plane surrounded by the terminals on the magnetic shunt plate, an X coil control line wound on each of the coil forms in the row in the X direction in an alternately reversed manner, both ends of the X coil line being connected to corresponding terminals located along the X direction, a Y coil control line wound on each of the coil forms in the column in the Y direction in an alternately reversed manner, both ends of the Y coil control line being connected to corresponding terminals located along the Y direction, reed switches accommodated in each of the coil forms, contact points of the reed switches corresponding to the magnetic shunt plate, and the reed switches being connected to a plurality of matrix crosspoints consisting of multiple connection wires in the direct

Abstract: An electromagnetic relay mounted within a casing comprises a coil provided with an axial core forming a magnetic circuit with a yoke and two L-shaped armatures. A first arm of each armature consists of a magnetic plate while a second arm serves to actuate movable contacts. The ends of the second arms cooperate with each other by interengagement of lugs so as to ensure synchronous operation of the armatures.

Abstract: A method for controlling the voltage and the load distribution, as well as for synchronizing, of several inverters the outputs of which can be connected to a common bus bar in which, for each inverter, a simulated control variable is formed and is compared as to amplitude and phase with a reference voltage which is the same for all inverters.

Abstract: Circuitry for applying electrical power to one or more load devices under control of a remotely located manually operable switch coupled to the circuitry by a single power transmission line. The circuitry responds to toggling of the remotely located switch to, for example, in a first state apply power to a first load, in a second state apply power to the second load, and in a third state apply power to both the first and second loads.

Abstract: Electrical relay apparatus in which a contact spring (35) is bowed rather than angularly flexed by the armature (16) to bring the contacts (28, 38, 34, 39) into or out of engagement. A first contact (38) is mounted at the crown of a slightly bowed spring (35) fixedly mounted at one end. The contact (38) is mounted at near the midpoint of the spring (35) spaced apart from a second, fixed contact (28) and the contacts (28, 38) are brought into engagement by the further bowing of the spring (35) by an armature (16) acting along the spring axis in the direction of its fixed end. A second contact (39) mounted on the underside of the spring (35) may be brought out of engagement with a second fixed contact (34) by the further bowing of the spring (35) for a break-before-make mode of operation.

Abstract: A solid state switching circuit using a capacitive feedback that creates a positive differential. This positive differential overcomes any half-wave operation of the solid state switches caused by lack of symmetry in its gating circuit.

Abstract: A combined pick and stringed instrument tuning device includes a relatively flat, substantially rectangularly shaped housing having a pick attached thereto and is small enough to be easily held in one's hand. A momentary contact push-button switch mounted on top of the housing controls an electronic tuning circuit by selecting one of several predetermined frequencies from a frequency generator. In one embodiment, the tuning circuit is mounted in the housing so that the tuning device is totally self-contained. Alternatively, the tuning circuit is remotely located and is controlled by a cable connected to the housing or by radio signals. The frequency selected is displayed on the housing and the frequency generator drives a strobe light located near the pick. In another embodiment, a microphone mounted on the housing converts sounds from the string being tuned to a signal which is compared to the preselected frequency.

Abstract: An automatic focus detecting and indicating device for an camera in which a contrast signal is coupled through first and second analog switches directly to a difference circuit and through a peak hold circuit, respectively. A third analog switch is coupled so as to discharge the value stored in the peak hold circuit. The three switches are operated by a control circuit which in turn operates in accordance with the direction of movement of the lens and the detection of a rising edge of the contrast signal so as to prevent the generation of a false focus signal at other than the point of true focus.

Abstract: A tuning aid for tuning musical instruments, particularly keyboard instruments, includes a sensor unit (12) which has an elongate capacitative sensor probe which is capable of extending across one octave of the instrument, and an octave switch (22) and a tone switch (20) on which are manually set the nominal octave and note of the string being measured. Amplifiers (16,24) including an AGC amplifier and controlled band-pass filters (18,26) are responsive to the octave and tone switches to select the measured tone. A divider (32) responsive to the octave switch divides the measured frequency by a power of two. A divider (38) is connected to the output of a crystal oscillator (36) to divide by a factor dependent upon the tone switch setting. The outputs of the two dividers are compared in a discriminator (34) which compares the two frequencies. A meter (50) displays the sense and magnitude of the discriminator output so as to display in terms of cents the amount by which the frequencies differ.

Abstract: An impedance converting circuit having an impedance circuit connected in series to a load circuit and an active element having a main electrode connected to both ends of the load circuit and a control electrode connected to a reference potential. In this case, an input signal is supplied across both ends of the serially connected load circuit and impedance circuit.

Abstract: A safety device for power driven equipment which mechanically locks an access door on the equipment in closed position until the power drive motor has coasted to a stop. A manually operated locking bolt for the access door is pivotally mounted on a housing in which the control components for the safety device are contained. A locking plate is rigidly mounted on the pivot shaft of the locking bolt within the housing for movement with the shaft and bolt. A solenoid operated locking lever is pivotally mounted in the housing and is engageable with the locking plate when the solenoid is energized to prevent movement of the locking bolt from its door locking position. A bolt mounted on the locking plate actuates a switch which is electrically connected in the drive motor control circuit to open the circuit when the lock bolt moves to an unlocked position.

Abstract: An object of the present invention is the provision of a new and improved vehicle anti-theft device wherein electrical switches are located in the operator compartment of the vehicle and must be actuated in proper sequence to transmit simple make or break functions through wires leading to electronic circuitry that is located in a locked area, and which controls the ignition circuit. Additional code actuated circuitry is provided to permit authorized personnel, e.g. parking attendants, to operate the vehicle.

Abstract: A load, such as a logic network of the TTL type, is connected in parallel across a plurality of direct-current sources designed to maintain a substantially constant operating voltage. Each source includes a control unit which compares the load voltage with a reference level in order to stabilize the output voltage of an associated current generator at that level. If the generator current drops below a certain minimum value, however, a threshold sensor in the control unit raises the reference level up to an amount equaling about twice the maximum divergence possible between the reference levels of different control units, thereby ensuring that all sources contribute simultaneously to the load current.

Abstract: A switching device, with a mechanism similar to that of a D'Arsonval galvanometer, acting responsive to current flow in a primary control circuit to close a switch in a secondary controlled circuit. The primary control circuit includes dual oppositely wound coils, and relative pivotal mounting is provided between the coils and permanent magnets. The pivotal movement therebetween, upon current flow, closes the switch.

Abstract: A frequency adaptive, power-energy re-scheduler (FAPER) that includes a frequency transducer that notes frequency or frequency deviations of an electrical system and logic means which controls and re-schedules power flow to a load unit in part on the basis of the deviations in frequency from a nominal frequency and in part on the needs to the load unit as expressed by an external sensor signal obtained from the physical system affected by the load unit.