Abstract: A precharged capacitor connected in parallel with the contacts of an open switch discharges through the switch upon closure. Oxides on the switch contacts are broken through upon closure of the switch to produce a good electrical connection. The capacitor provides sufficient voltage and transient current to clean the switch contacts. A microprocessor having signals of only 5 volts can interrogate a plurality of such switches by multiplexing some semiconductor switching circuits that energize the interrogated switches and by synchronously multiplexing some microprocessor input circuits. The microprocessor's input circuits therefore receive signals indicating the status of each switch in turn.

Abstract: A transformerless power supply and display energizing circuit for a clock circuit with a duplex optoelectronic display driven by a low voltage integrated clock circuit having positive and negative voltage input terminals and the duplex display having a first terminal connected to a first common cathode and a second terminal connected to a second common cathode of the display for energizing it. The transformerless circuit is powered from an AC source. An impedance, which may be either resistive or reactive, reducing the AC voltage to a level suitable for the integrated clock circuit. The transformerless circuit generates synchronous DC level-shifted pulse trains for driving the positive input terminal of the integrated clock circuit alternately between a first voltage and a reference voltage while synchronously driving the display first terminal between said first voltage and a voltage of equal amplitude and opposite polarity. The display second terminal is held at the reference voltage.

Abstract: The invention comprises flexible handles which are adjustable in length, and which are attached to athletic shoes. The handles may be attached at various points on each shoe, adjusted to the desired length, and the wearer can grasp the handles to aid and augment exercises, and muscle toning routines.

Abstract: An electronic organ tone generating technique produces a harmonic equivalent of a sawtooth wave. In one embodiment square waves generated by a conventional tone generator are applied to a one shot multivibrator, the output of which is a series of narrow rectangular pulses having a flat harmonic spectrum with both even and odd harmonics present. The narrow rectangular pulses are applied to a 3db per octave filter to produce a waveform, the harmonic content of which is equivalent to that of a sawtooth wave. In this embodiment, the pulse width remains constant regardless of the frequency of the pulse train. In a second embodiment, the duty cycle at each octave when moving up the keyboard is doubled to compensate for amplitude falloff which may occur in the filtered signal.

Abstract: An electronic organ includes a read-only memory which stores eight bit binary words each having a digital value proportional to the frequency of a different note. When a chord keyswitch is actuated, a corresponding chord selector controlled by a multiplexer circuit causes the randomly addressable memory to sequentially generate binary words corresponding to the frequencies of the notes forming the selected chord. Each binary word is stored in a latch associated with a different universal tone generator capable of generating any tone as controlled by the stored binary word. Each universal tone generator includes a comparator which recognizes a match between the associated latch and a counter which receives clock pulses from a single fixed frequency oscillator. The comparator resets the counter and generates an output pulse which is divided to form an audible tone signal.

Abstract: An electrical musical instrument having a digital circuit which automatically generates selected chordally related tone signals in response to manual selection of a root note. A root encoder provides a binary code representative of the root note in response to note selections, and an interval code generator automatically provides code signals having binary number values equal to the number of half steps from the root for a given interval. An adder arithmetically adds the root code and the interval code to generate a code for a chordally related note having both octave and note information corresponding to the automatically generated tone signal. In one mode of operation, the root code represents the root of the root-fifth pair of highest priority around the circle of fifths selected on a manual keyboard. In another mode, the root code is representative of a note selected on the pedal clavier.

Abstract: An arpeggio circuit for an electronic organ employing digital encoding, decoding and code conversion techniques to semiautomatically generate an arpeggio effect composed of tone signals having an octaval relationship and corresponding to selected note keys held down on an accompaniment keyboard. The rate of generation and order of the arpeggio tone signals is controlled by means of a plurality of manually actuatable arpeggio control switches. A plurality of individually identifiable control signals are sequentially generated in response to sequential actuation of the plurality of control switches. The control signals are binarily encoded. Tone signals provided by a set of tone generators are selectively associated with appropriate ones of the encoded control signals by a tone selector circuit which provides the selected one of the tone signals to an arpeggio output tone signal generating circuit when the associated encoded control signal is being generated.

Abstract: An electric organ utilizes digital encoding and time division multiplexing to transfer both function selection and note selection information from manually operable switches to respective memories, and to simultaneously produce tone signals corresponding to stored note selection information. A single encoding circuit encodes in binary form the function and note selection information during successive scanning periods established by a single multiplexing circuit. A plurality of stored note codes are transferred on a time division multiplexing basis to a note selector which selectively produces all of the selected tone signals, on one output in multiplexed form. The tone signals are demultiplexed to generate a corresponding plurality of tone signal outputs. An octave selection circuit which is responsive to a part of each note code selectively reduces the frequency of the demultiplexed tone signals.