Abstract: A light measuring apparatus comprising a photoelectric element exposed to incident light and coupled to a plurality of parallel-connected capacitors which integrate the photoelectric current output from the element. Control means successively switch each of the capacitors in parallel as the photoelectric current charges a first previously switched capacitors in accordance with the voltage integrated on the capacitors as sensed by a comparator. After a predetermined time, the parallel charged capacitors are discharged through a constant current source, with the discharge time being digitally monitored to produce a digital output proportional to the incident light level.

Abstract: A teaching aid for piano and other keyed musical instruments. The device has switches electrically connected to a matrix array and mechanically linked to each key for detecting each key depression, an LED associated with each key for signalling the keys which should be played and an alphanumeric display for showing notes in literal and octave notation and for showing the student's position in a composition or exercise. The displays are connected in a matrix array and along with the key sensing switches are connected through interface circuitry to a microcomputer. The microcomputer stores a sequence of musical steps forming a composition and compares played notes to the stored sequence. When the compared notes and the depressed keys are identical, the student is signalled and the microcomputer advances to the next musical step. When there is an error, the microcomputer recycles the same musical step.

Abstract: Apparatus including amplifier and peak-detecting circuits receives an electrical signal representative of an aural tone containing a pitch to be determined and produces therefrom a pulse train having a pulse reoccurrence frequency (PRF) substantially equal to the pitch of the tone. The pulse-to-pulse period of the pulse train is measured by applying the pulse train to control circuits that alternately enable and disable digital counters clocked by a binary signal of a PRF substantially greater than that of the pulse train. The digital counters produce counts representative of the period of the pulse train which are decoded and applied to a display unit to provide a visual indication of the pitch contained in the received electrical signal.

Abstract: In the disclosed motion picture system a shutter drive control circuit renders it possible to operate a rotary shutter in various exposure control modes including a mode in which rotation of the shutter is stopped for each long exposure of motion picture frame, the system can defer release of the shutter to the exposure aperture closed position pending completion of a picture frame exposure in any of the modes. The system terminates the preceding manual actuation of a shutter trigger when the taking of the particular picture frame is in progress.

Abstract: In order to suppress the high-frequency currents in bearings of shafts, the bearing capacity is arranged in the configuration of an electric quadrupole in such a manner that the high frequency voltage becomes a minimum. In the case of ungrounded shafts, a further impedance is provided between the bearing housing and the housing of the treatment chamber such that the sum of this further impedance and the impedance of the shaft are great compared to the bearing impedance. Additionally, a low resistance in the form of a sliding contact is shunted across the bearing impedance. The further impedance according to one embodiment is a capacitance and in another embodiment is a parallel L-C resonant circuit which is connected in series with the bearing. The capacitance of the L-C circuit is formed by an insulating plate and the inductance by a winding.

Abstract: In order to suppress the high-frequency currents in bearings of shafts, the bearing capacity is arranged in the configuration of an electric quadrupole in such a manner that the high frequency voltage becomes a minimum.

Abstract: A sound responsive color organ includes a transducer to convert sound to electricity, an amplifier to increase the level of electricity, and an automatic gain control that operates under the influence of a time dependent circuit to control the output level of the amplifier. The time dependent circuit operates at one rate when increasing the amplifier gain and at a second rate when decreasing the amplifier gain. A network is included to adjust the frequency response of the amplifier to predetermined limits. The amplifier output is used to control switching devices that turn on and/or off lights in a display located behind color masks. Located in front of the color masks is a lenticular surface which further affects the light sources to yield geometric patterns comprising the effect of the masks and the lens types.

Abstract: A HVDC system has two converter stations, each of which has two converters connected in cascade to operate as a rectifier or an inverter and the stations are connected through a d.c. power transmission line to each other and are connected to respective a.c. power sources through the a.c. power transmission lines. Each converter is controlled depending on the difference between a current reference for the HVDC system and an actual current flowing in the HVDC system when the converter operates as a rectifier, and controlled depending on the output of the constant margin angle control circuit when the converter operates as an inverter. When the converter operation condition is changed, i.e. another converter operates in addition to the converters in operation or the direction of power transmission in the HVDC system is changed, the current reference for the HVDC system is reduced depending on the d.c. voltage during a predetermined period.

Abstract: A direct current interrupter comprising a plurality of two-point interrupter units each including a pair of interrupting portions. The interrupting portions of the interrupter units are arranged at regular angular intervals on a circle with the axial line of the interrupter as its center and arranged parallel to the axial line. An input terminal is provided to supply shunted current to one interrupting portion of each interrupter unit. An output terminal is provided to receive the shunted current from the other interrupting portion of each interrupter unit. A first common connecting portion and a second common connecting portion near the axial line. The main current flows through a conductor line from the main current input terminal to the first common connecting portion and shunted.

Abstract: A focus detecting device having a release lens for reforming the image of an object which is formed between a lens and the focal plane of the lens. A mirror is provided between the release lens and an image reforming plane for dividing the primary image into two secondary images. Two light receiving element arrays provided in the image forming planes of said secondary images provide outputs to a signal processing circuit for comparison to produce a signal indicating whether or not the lens is focussed on the object. The mirror for dividing the primary image into two secondary images, shifts the two secondary images in opposite directions on the light receiving element arrays at the time of defocussing so that the difference between the outputs of said two light receiving element arrays is not zero.

Abstract: A program type electric shutter wherein a shutter blade which is also a diaphragm blade and is made to be able to latch an exposure warning indicating device to be inoperative just before the beginning of the opening of the shutter blade and a diaphragm device which can open and close a window for a light receiving element are operatively connected with each other in order to prevent the mis-indication of the exposure warning indicating device. This electric shutter is provided with an electric self-timer device and a flash controlling circuit.

Abstract: A small lightweight electronic device to indicate the finger positions of a fretted stringed instrument represented by the musical intervals or chords in any key. The device has a series of on-off switches representing each of the desired musical keys and a series of switches representing the individual musical intervals over a desired range. The necessary circuitry is provided between these switches and a display of the frets and strings of the instrument such that the finger positions represented by a chord or series of musical intervals in a selected key are visually indicated on the display. Professional musicians and students or teachers of music for fretted stringed instruments can, using this device, visualize the location of intervals or chords of any key.

Abstract: Instant scale shifting by predetermined increments is provided in a musical instrument tuning device by means of a programmable phase locked loop and crystal-controlled oscillator combination. The incremental scale steps are extremely accurate without need for recalibration and with no change in the tone intervals.

Abstract: A device for the measurement of the number of cycles or half-cycles of a tone by counting the cycles during a reference time which is proportional to the cycle time of the tone to be measured, comprising a store for the cycle times, a comparator, a subtraction device in which a constant value is subtracted from the counted number of tone cycles, decoders, displaying devices for the oscillation error and the polarity sign, a retriggerable mono-flop for the oscillation existence signal, a flip-flop for a wait signal, a mono-flop for a read signal and logic elements for enabling the oscillation counter and the reference pulse counter.

Abstract: The invention comprises a method and apparatus for the tuning of a piano and other similar musical instruments to equal temperament. A transducer is operative to receive two notes being struck, one of which is tuned and the other of which is to be tuned. The electrical output signal provided by the transducer is processed by bandpass filtering to isolate a predetermined beat note which is associated with the two notes being struck. The filter output signal is applied to an output transducer such as headphones which provides an audible rendition of essentially only the intended beat note.

Abstract: A transducer produces an electrical signal representing the frequency of a tone produced by the vibrating string of a musical instrument. Circuit means convert the electrical signal into a visually perceivable form which moves or appears to move in unison with the vibrating string. The signal from a frequency generator representing the desired frequency operates a strobe light source which is operatively associated with the visual vibrating motion display. When the string is in tune with the pre-selected desired frequency from the generator, the vibratory motion appears to stop and the strobe light or vibrating element appears to stand still.

Abstract: A power supply system for a number of functional units distributed along a transmission in which each unit gets its supply from a constant voltage circuit connected across the transmission line. Each unit may have a low power and a high power state. The power supply which is located at one end of the transmission line is a constant voltage supply with current limiting features. The constant voltage circuits each comprises a Zener diode connected in series with an adjustable constant current circuit and a system for setting the constant current circuit on either the low or the high power state. When the high power state is set, the voltage across the constant current circuit is sensed and if this voltage is too high, the constant current is further increased until the current limiting of the power supply operates thereby decreasing the voltage across the constant current circuit to a safe value.

Abstract: A switch and latch arrangement for use in a washing appliance of the type providing for user selection of one of two dry cycle options in which option selection is coupled to the door latch mechanism in such a manner that movement of the door latch means from a latched to an unlatched position assures that a predetermined one of said options is automatically selected, requiring manual override at that selection by the user after latching the door if the other option is desired. In an illustrative embodiment, the switch and latch arrangement is used in a dishwasher which provides for user selection of a non-heated dry option or a heated dry option. An option selection button, movable between a first portion for enabling the non-heated option and a second position for enabling the heated dry option is provided.

Abstract: A device for teaching music comprising, in combination, a set of pegs or keys subdivided into seven groups corresponding to the seven musical notes, a set of cards obtained by a sheet material, each card containing a musical passage consisting of coded holes corresponding to the notes of the passage, and means for reproducing the sounds corresponding to each of the seven notes when the respective pegs selectively associated with each hole are first introduced into said holes, and then sequentially depressed.

Abstract: This invention relates to the arrangement of a switching network intended to be used within an electrical utility station switchyard, which improves the security of power delivery to various loads while at the same time allowing a reduction in the number of required circuit breakers and related gear. The invention is a switching network comprising six conducting branches, each branch containing at least one switching means such as a circuit breaker. The branches are connected at their ends so as to form four 3-sided rings, each branch forming a side of and being shared by two of the rings. As a result, four triple-connected nodes are formed at the end connection points of the branches while the connections between adjacent pairs of switching means within a branch form double-connected nodes. These nodes serve as points for connection thereto of source/load elements, and each node is isolatable from the other nodes by the operation of a maximum of three of switching means.