Abstract: Disclosed is a ringing power supply for developing a ringing signal having an AC voltage combined with a regulated DC voltage, of magnitude smaller than the magnitude of the AC voltage, from a source having the AC signal combined with an unregulated DC voltage. The ringing power supply comprises a control circuit responsive to the AC and DC voltages of the source for developing a replica signal of the regulated DC voltage with its superimposed AC voltage, and a regulator responsive to the developed replica signal and to the source for providing the desired ringing signal.

Abstract: A battery charger circuit for providing a charging current to a rechargeable battery from AC line voltage. The charger circuit is especially adapted for use in an emergency light and includes circuitry to provide automatic charging current shut-off when the battery is fully charged. Failure of AC power is detected by the charger circuit, and current is applied to an emergency lamp in response to such failure. Circuitry is included for monitoring the charge state of the battery and for interrupting discharge current to the lamp from the battery when the charge state falls below a predetermined limit. Provision is included for use of the battery charger circuit in a portable lantern configuration.

Abstract: Dental apparatus having a plurality of dental instruments, holders for the instruments, signal transmitters each operable to transmit an extraction signal when an instrument is extracted from its holder, and a logic-actuation circuit for each instrument connected to a respective signal transmitter and to all the other logic-actuation circuits. Each actuation circuit can generate an actuation signal for its associated instrument, and a blocking signal for supply to the other actuation circuits, when an extraction signal is transmitted and when no blocking signal is supplied by any of the other actuation circuits. A single connecting line interconnects the actuation circuits to transmit blocking signals therebetween, and logic identification circuits associated with the actuation circuits are each connected to the connecting line and to an input and to an output of the associated actuation circuit.

Abstract: A switching matrix utilizing connection modules, for the connection of peripherally arranged electrical measuring devices, over selectable lines of a line group specifically associated with a matrix, to the peripheral terminals of specimens to be measured, such as electrical components, circuit board, assemblies, communication devices and the like, wherein the connection modules are designed with two poles, each of which is selectively connectable to a respective peripheral terminal of a specimen or a device over controllable switching means, and further controllable switching means for selectively connecting the first pole of a connection module to the second pole thereof at the matrix side of the first mentioned switching means associated with such second pole, in the event said last mentioned switching means is open, each of such poles providing access from such a terminal to separate line subgroups, from which a line is then selected over additional controllable switching means.

Abstract: An adapter system for a stringed musical instrument having a tuning key and a string connected to the tuning key for adjusting the pitch of sound rendered by striking the string attached to said key. A limit stop is operatively mounted on the instrument along with a,rotational stop mounted on the key for interacting with the limit stop to confine the rotational movement of the tuning key to a certain predetermined arc. The limit stop can be adjusted to selectively change the angular arc. An internal adapter cylinder is operatively mounted on the shaft of the tuning key where the tuning key shaft is of a non-circular configuration. An upper cylinder and a lower cylinder are operatively mounted with respect to the internal adapter cylinder. The adapter cylinder is provided with a recess which accommodates a cylindrical insert used when the tuning key is not provided with a shoulder portion.

Abstract: A control system, for a machine and the like having at least one cycle made up of at least two events, utilizes momentary switching devices to actuate each cycle. The control system includes a control circuit having momentary switching devices, digital circuitry for latching the control circuit in various modes of operation, and timing circuitry responsive to the digital circuitry for timing at least one event of the cycle; and gate circuit means controlled by semiconductor switching devices for regulating at least another event of the cycle in response to the control circuit.

Abstract: An isolated electrical power generation system is described with multiple isochronous, load-sharing engine-generator units. The system includes load sensing means for generating a signal representing the individual power output of each engine-generator unit, means for generating a signal representing the total power output of all the engine-generator units in the system, and load-sharing means responsive to deviations between each individual power output signal and the total power output signal for controlling the fuel inputs to the respective engines in the various units. A load simulating means responds to the occurrence of a preselected condition, such as an excessive temperature, in an individual unit for adding a simulated power output signal to the individual power output signal for that particular unit.

Abstract: Two reed switches are alternately closed by a magnet rotating with a shaft of a water meter or the like which is to be read remotely. A capacitor discharges through the reed switches when the same are closed, increasing the switch current without increasing the external power source current, thereby producing temporary partial fusion of the switch contacts and maximum contact effectiveness. A low-pass filter and a snap action circuit such as a Schmitt trigger are connected to the switches to eliminate the effects of contact bouncing and noise signals from the output of the circuit.

Abstract: A support mechanism for keyboards of an electronic organ is provided, having a plate spring which mates at one end with a stopper projection formed on the lower end of a back side plate of a fixed plate attached to a keyboard chassis, the other end of the plate spring being inserted into the back end of the keyboard through a notch hole formed in a front side plate, such being at a different level than the back plate projection, and with a fulcrum part of the back end of the keyboard being made to link with a fulcrum projection formed in the front side plate.

Abstract: A stop tablet mechanism particularly suited for electric organs wherein a plurality of stop tablets lie in closely spaced apart side-by-side relation, the stop tablets being pivotally supported on a tablet rail and spring-biased to assume a neutral position from which they can be momentarily moved up or down against the action of the spring.

Abstract: A brass wind musical instrument comprises two main tubes along which a plurality of bypasses are arranged, the bypasses being inserted in series into the corresponding main tubes by the action of valve assemblies; an intermediate tube; a first changeover valve, which, while remaining inoperative, effects communication between a mouthpiece and one end of one of the main tubes, as well as between one end of the other main tube and one end of the intermediate tube, and which, while being operated, ensures communication between the mouthpiece and said one end of the other main tubes, as well as between said one end of said one main tube and said one end of the intermediate tube; and a second changeover valve, which, while remaining inoperative, carries out communication between a bell and the other end of said one main tube, as well as between the other end of the other main tube and the other end of the intermediate tube, and, when operated, attains communication between the bell and the other end of the other m

Abstract: A demand controller includes a microprocessor which is programmed to input data from switches on a control panel and output data to a set of eight circuits which control the operation of loads. Peak power demand is maintained below a preset DEMAND OBJECTIVE by selectively shedding these loads. The shed level for each load is not fixed, but instead, varies as a function of the rate at which total power demand is increasing. This rate is calculated by the microprocessor and the resulting shed level index (i) is employed to select the proper shed level for each load from a stored shed level matrix.

Abstract: An automotive dome light control switch maintains the dome light illuminated for a first time period after a door is shut and for a second, shorter, time period after the ignition is turned off. If the ignition switch is turned on during the first time period, the dome light is immediately extinguished. The dome light may always be turned on by the dome light switch.

Abstract: An adjustable pitch drum consists of a drum shell having an open end, a drum head pitch changing mechanism, and a supporting structure mounting the pitch changing mechanism to the drum shell. The pitch changing mechanism consists of a threaded rod adjustably threaded to the supporting structure, a drum head clamping hoop mounted coaxially on the rod for rotation thereabout, and a drum head tensioning hoop non-rotatably mounted on the other end of the rod. Rotation of the drum head and its clamping hoop about the rod varies the tension of the drum head on the tensioning hoop, thereby changing the pitch of the drum. Movement of the threaded rod in the supporting structure changes the spacing of the drum head from the drum shell open end, thereby changing the resonance characteristics of the drum assembly.

Abstract: Switching means for automatically determining which note in the entire musical spectrum is closest to an input frequency and display means for generating a visual display of the frequency difference between said input signal and the correct frequency of said note, specifically adapted for the tuning of musical instruments.

Abstract: An adjustable pitch drum consists of a drum shell of any suitable shape having an open end, a drum head pitch changing mechanism, and a supporting structure mounting the pitch changing mechanism to the drum shell. The pitch changing mechanism consists of a threaded rod adjustably threaded to the supporting structure, a drum head clamping hoop mounted coaxially on the rod for rotation thereabout, and a drum head tensioning hoop non-rotatably mounted on the other end of the rod. Rotation of the drum head and its clamping hoop about the rod varies the tension of the drum head on the tensioning hoop, thereby changing the pitch of the drum. Movement of the threaded rod in the supporting structure changes the spacing of the drum head from the drum shell open end, thereby changing the resonance characteristics of the drum assembly.

Abstract: Display apparatus provides for concurrent visual display and audible reproduction of musical notes individually or in plural. In one embodiment, a top octave generator operates responsively to an input signal having a characteristic which is variable in accordance with the relative positioning of visual display components of the apparatus. In a second embodiment a tone generator provides top octave and lower octave signals and selection is made for audible reproduction by a switching arrangement responsive to relative positioning of visual display components.

Abstract: A neck for a stringed musical instrument has a metallic frame running substantially the entire length of the neck to provide a fingerboard and also to provide support for a peghead at the outer or upper end of the neck. The peghead portion of the frame cooperates with a mounting plate which may be varied in shape to suit different peghead styles and arrangements of the machine heads attached to the peghead, thereby allowing identical frames to be used in making necks with various different peghead designs. In addition to the frame, a major portion of the neck is comprised of structural foamed plastic with the construction being such as to enable quantity manufacture of the necks at low unit cost.

Abstract: A power sustaining thermal switch placed in shunt with an existing electrical switch results in the flow of electricity through the thermal switch for a predetermined period of time after the existing switch has been turned off. Thus sustaining power in the thermal switch circuit for supply to an electrical device.

Abstract: A cymbal has a first mounting aperture generally centered on the cymbal and second mounting aperture laterally offset from the first mounting aperture, and has different characteristic tones when mounted to a support stand by the first and second apertures respectively.