Voltage controlled chord organ

Claim 2

An electronic organ, comprising a voltage tunable tone signal oscillator system, said oscillator system including at least one oscillator, a plurality of organ keys arranged in an array, a resistive voltage divider, means for applying voltage to one end of said voltage divider, means for connecting the other end of said voltage divider to a point of reference potential, taps taken from said voltage divider, a separate two contact key switch operable by each of said keys, said key switches each having one of said contacts connected to a different one of said taps, a common bus line of substantially zero resistance, means connecting all the others of said contacts to said common bus line, and control means connecting said common bus line to energize said at least one oscillator, said taps being so selected that said at least one oscillator oscillates at pitches which vary as fon/12, where n is an integer including zero identifying said key switches and fo is the lowest frequency called forth by actuating said keys, and separate diodes connected in series with each of said key switches, said diodes being poled to be highly conductive of current from said resistive voltage divider through said switches.

Claim 3

The combination according to claim 1, wherein Vn is the voltage of the nth tap of said voltage divider and wherein Vo is the voltage of the oth tap, and wherein a further voltage divider extends between said oth tap and said point of reference potential, said further voltage divider having a voltage Vs at its division point, and wherein the resistors of said resistive voltage divider and of said further voltage divider are selected to provide voltages according to the equation K(Vn - Vs) (Vo -Vs) (2)n/12, wherein K is a constant, Vs is a supply voltage for said multivibrator oscillator, Vo is a refernece voltage and Vn is a frequency determining voltage.

Claim 4

The combination according to claim 2, wherein said oscillator system includes three oscillators connected respectively to said common line via diverse tuning resistances selected to control said three oscillators to produce the notes of a musical chord.

Claim 5

The combination according to claim 3, wherein said oscillators produce root frequency, third frequency and fifth frequency, respectively, and wherein is included switch means for at will adjusting that one said diverse resistance which controls the frequency of said third frequency so as to provide at will either a major or a minor chord.

Claim 6

The combination according to claim 4, wherein is further provided a variable resistance in series commonly only with said diverse resistances taken in parallel, and means for varying said variable resistance to effect a common frequency variation of all said oscillators.

Claim 7

The combination according to claim 5, wherein is included a sample and hold circuit connected to said common bus line, said sample and hold circuit including means for producing and storing a voltage equal to Vn for at least the time normally required to play a measure of music, said means for producing and storing a voltage equal to Vn being included in said control means, and means for applying said a voltage equal to Vn to said at least one oscillator in frequency controlling relation to said at least one oscillator.

Claim 8

The combination accorDing to claim 6, wherein said sample and hold circuit includes an input lead, a power lead, a first NPN transistor having a collector connected directly to said power lead, said first NPN transistor having a base, a bias resistance connected between said power lead and said base of said first NPN transistor, a second NPN transistor connected collector to emitter from said base of said first NPN transistor to ground, a third PNP transistor having its emitter connected directly to the emitter of said first NPN transistor, its collector connected to the base of said second transistor and its base connected to said input lead, a FET having a source electrode, and a drain electrode and a gate electrode, means connecting said source electrode to the emitters of said first and third transistors, a fourth NPN transistor having a grounded emitter, a base connected to said input lead and a collector connected to said gate electrode, a connection directly from said power lead to said collector of said fourth transistor, a fifth NPN transistor having its collector connected directly to said power lead and its base connected via a bias resistance to said power lead and its emitter connected to ground via a load resistance, a sixth NPN transistor having its collector emitter circuit connected between said base of said fifth NPN transistor and ground, a seventh PNP transistor having its collector connected to the base electrode of said sixth transistor and its emitter connected to the emitter of said fifth transistor, said drain electrode being connected to the base of said seventh transistor, and selective means connecting said drain electrode via a resistance or a store capacitance to ground, and means biasing the base of said first transistor to ground.

Claim 9

The combination according to claim 6, wherein said sample and hold circuit includes a voltage input line, a voltage output line, means including a FET for coupling said lines, means maintaining said FET non-conductive in absence of at least a predetermined voltage on said input lead, means for rendering said FET conductive when said input lead acquires a greater than said predetermined voltage, a storage capacitor connected between said output line and ground, and means for charging said capacitor when the voltage of said input lead exceeds the voltage of said output lead and for discharging said capacitor via said FET when said output lead exceeds the voltage of said input lead.

Claim 10

The combination according to claim 6, wherein said sample and hold circuit includes a storage capacitor, an input line, an output line, means for maintaining said capacitor discharged so long as the voltage on said input line is substantially zero, means for maintaining said output line in fixed relation to the voltage of said capacitor, means including a solid state gate connecting said input line to said capacitor, mean normally maintaining said gate non-conductive while said voltage on said input line is substantially zero, and means responsive to the voltage on said input lead when said input lead exceeds a predetermined voltage for rendering said gate conductive.

Claim 11

The combination according to claim 1 wherein is provided adjustable resistance connected in series between said control means and said at least one oscillator, said at least one oscillator being arranged to operate at a frequency proportional to the voltage of said voltage source, and inversely proportional to the value of said adjustable resistance.

Claim 12

The combination according to claim 2, wherein is included a sample and hold circuit connected to said common bus line, said sample and hold circuit including means for producting and storing a voltage equal to Vn for application to said at least one oscillator for a time at least equal to the duration of a measure of music.

Claim 13

In an electronic chord organ, an array of keys, means for generating a control voltage in response to playing of a selected key of said array of keys for only part of a measure of music, said voltage having a value which is a function of the selected key, a two terminal sample and hold device having an input terminal connected to sample said voltage and an output voltage terminal, said sample and hold circuit having a hold time of at least one measure of said music for maintaining a musical chord at constant amplitude, a triad of voltage controlled means responsive to the voltage at said output terminal for calling forth said muscial chord of notes and means responsive through said sample and hold circuit to said playing of a selected key for generating a rhythmic series of impluses for sounding the notes of said chord through gate means in a predetermined tempo and rhythm during said hold time.

Claim 14

In an electronic chord organ, an array of keys, means for generating a control voltage in response to playing of a selected key of said array of keys for only part of a measure of music, said voltage having a value which is a function of the selected key, a two terminal sample and hold device having an input terminal connected to sample said voltage and an output voltage terminal, said sample and hold circuit having a hold time of at least one measure of said music for maintaining a musical chord at constant amplitude, a triad of voltage controlled means responsive to the voltage at said output terminal for calling forth said muscial chord of notes and means responsive through said sample and hold circuit to said playing of a selected key for generating a rhythmic series of impluses for sounding the notes of said chord through gate means in a predetermined tempo and rhythm during said hold time.

Claim 15

In an electronic chord organ, means a triad of a voltage controlled for generating any selected one of a plurality of chords in response to playing of a selected key of said organ for part of a measure, said first means including a sample and hold circuit means responsive to said selected key for maintaining each of the selected chords at constant amplitude for plural measures following release of said selected key, means responsive through said sample and hold circuit means to said selected key for rhythmically sounding the notes of said each of said selected chord through gate means in a predetermined tempo and rhythm during operation of said means for maintaining, said means for rhythmically sounding including means for generating a series of rhythmic percussive pulses in said tempo and rhythm.

Claim 16

In an electronic chord organ, means a triad of a voltage controlled for generating any selected one of a plurality of chords in response to playing of a selected key of said organ for part of a measure, said first means including a sample and hold circuit means responsive to said selected key for maintaining each of the selected chords at constant amplitude for plural measures following release of said selected key, means responsive through said sample and hold circuit means to said selected key for rhythmically sounding the notes of said each of said selected chord through gate means in a predetermined tempo and rhythm during operation of said means for maintaining, said means for rhythmically sounding including means for generating a series of rhythmic percussive pulses in said tempo and rhythm.

Claim 17

An organ system comprising a triad of voltage controlled oscillators having each a control terminal, means for applying control voltages to all said terminals, means responsive to said voltages for rendering said oscillators operative to oscillate at the frequencies of a triad muscial chord, said means for applying control voltages including voltage dropping variable tuning resistances connected between said means for applying control voltages and said control terminals of said oscillators, respectively, means for generating a rhythmic series of impulses in predetermined tempo, means responsive to said impulses for gating on the outputs of said triad of voltage controlled oscillators in rhythmic sequence, a series of keys of a keyboard, and means responsive through said means for applying control voltages to playing of any one of said keys for initiating operation of said means for generating said rhythmic series of impules respectively, until one of said keys is again played, and said means for applying control voltage comprising means responsive to playing of the last mentioned one of said keys for re-initiating operation of said means for generating said rhythmic series of impulses.

Claim 18

An organ system comprising a triad of voltage controlled oscillators having each a control terminal, means for applying control voltages to all said terminals, means responsive to said voltages for rendering said oscillators operative to oscillate at the frequencies of a triad muscial chord, said means for applying control voltages including voltage dropping variable tuning resistances connected between said means for applying control voltages and said control terminals of said oscillators, respectively, means for generating a rhythmic series of impulses in predetermined tempo, means responsive to said impulses for gating on the outputs of said triad of voltage controlled oscillators in rhythmic sequence, a series of keys of a keyboard, and means responsive through said means for applying control voltages to playing of any one of said keys for initiating operation of said means for generating said rhythmic series of impules respectively, until one of said keys is again played, and said means for applying control voltage comprising means responsive to playing of the last mentioned one of said keys for re-initiating operation of said means for generating said rhythmic series of impulses.

Claim 19

In an organ system, a voltage controlled tone oscillator, a voltage sample and hold circuit comprising an amplifier having an input circuit and an output circuit, means for establishing a control voltage selectively in response to closure of a selected key switch of a plurality of key switches of said organ system, means including at least one diode for applying said control voltage less at least one diode voltage drop to said input circuit, means deriving a further voltage equal to said control voltage from said output circuit, and means for applying said further voltage to said voltage controlled oscillator in voltage controlling relation thereto, said voltage sample and hold circuit having a hold time of about at least 20 seconds.

Claim 20

In an organ system, a voltage controlled tone oscillator, a voltage sample and hold circuit comprising an amplifier having an input circuit and an output circuit, means for establishing a control voltage selectively in response to closure of a selected key switch of a plurality of key switches of said organ system, means including at least one diode for applying said control voltage less at least one diode voltage drop to said input circuit, means deriving a further voltage equal to said control voltage from said output circuit, and means for applying said further voltage to said voltage controlled oscillator in voltage controlling relation thereto, said voltage sample and hold circuit having a hold time of about at least 20 seconds.

Claim 21

The combination according to claim 15, wherein said sample and hold circuit includes a storage capacitor, and means for adjusting the voltage of said storage capacitor substantially instantaneously on closure of any of said key switches.

Claim 22

In an electronic organ, a keyboard having an array of keys, an array of two contact key-switches operated by said keys to close when said keys are actuated; a resistive voltage divider having a tap connected to each of said keyswitches, a diode connected conductiveLy between each of said taps and one contact of each of said keyswitches, and a common bus connected to the others of said contacts, a source of voltage connected to one end of said divider, a reference point connected to the other end of said divider, and resistance connected between that one of said taps connected to the last one of said array of keyswitches and said reference point, a voltage terminal connected at a point of said resistance, and a voltage responsive multivibrator oscillator connected jointly to said common bus and to said voltage terminal and arranged to oscillate at a frequency which is a function of the difference of the voltages of said common bus and of said terminal.

Claim 23

In an electronic organ, a keyboard having an array of keys, an array of two contact key-switches operated by said keys to close when said keys are actuated; a resistive voltage divider having a tap connected to each of said keyswitches, a diode connected conductiveLy between each of said taps and one contact of each of said keyswitches, and a common bus connected to the others of said contacts, a source of voltage connected to one end of said divider, a reference point connected to the other end of said divider, and resistance connected between that one of said taps connected to the last one of said array of keyswitches and said reference point, a voltage terminal connected at a point of said resistance, and a voltage responsive multivibrator oscillator connected jointly to said common bus and to said voltage terminal and arranged to oscillate at a frequency which is a function of the difference of the voltages of said common bus and of said terminal.

Claim 24

In an organ system having a plurality of key switches respectively allocated to notes of the muscial scale, a plurality of resistances all connected in a series chain, a source of voltage connected to one end of said chain, a ground point connected to the other end of said chain, a common bus, the junctions of said plurality of resistances being at voltages Vn, a plurality of diodes connected in conductive relation between junctions of said resistances and said common bus, means for deriving a voltage Vs responsive to the current flowing in said chain, a sample and hold circuit, said sample and hold circuit including an amplifier having an input terminal and an output terminal, means connecting said input terminal to said common bus, three multivibrator oscillators responsive jointly to Vs and Vn, means including variable resistances respectively connecting said output terminal in common to said three multivibrator oscillators, said variable resistances including a resistance in series commonly with all said oscillators for concurrently tuning all said oscillators, said variable resistances including resistances respectively connected individually in series with each of said oscillators for individually tuning said oscillators, means for deriving tone signals from said oscillators, and means for acoustically transducing said tone signals.

Claim 25

In an organ system having a plurality of key switches respectively allocated to notes of the muscial scale, a plurality of resistances all connected in a series chain, a source of voltage connected to one end of said chain, a ground point connected to the other end of said chain, a common bus, the junctions of said plurality of resistances being at voltages Vn, a plurality of diodes connected in conductive relation between junctions of said resistances and said common bus, means for deriving a voltage Vs responsive to the current flowing in said chain, a sample and hold circuit, said sample and hold circuit including an amplifier having an input terminal and an output terminal, means connecting said input terminal to said common bus, three multivibrator oscillators responsive jointly to Vs and Vn, means including variable resistances respectively connecting said output terminal in common to said three multivibrator oscillators, said variable resistances including a resistance in series commonly with all said oscillators for concurrently tuning all said oscillators, said variable resistances including resistances respectively connected individually in series with each of said oscillators for individually tuning said oscillators, means for deriving tone signals from said oscillators, and means for acoustically transducing said tone signals.

Claim 26

The combination according to claim 18, wherein the sample and hold sustain time of said sustain circuit extends over plural measures of music played on said organ.

Claim 27

The combination according to claim 18, wherein one of said voltage controlled oscillators is a root voltage controlled oscillator, another of said oscillators is a third voltage controlled oscillator, and still another of said oscillators is a fifth voltage controlled oscillators, and wherein is provided switch means for at will modifying the frequency of said third voltage controlled oscillator between major third and minor third frequencies by introducing a further resistance between said bus and said third voltage controlled oscillator.

Claim 28

The combination according to claim 18, wherein said sample and hold circuit connected between said common bus and said oscillators includes means for compensating for diode voltage drops in said plurality of diodes such that the voltage at the output of said sample and hold circuit equals Vn.

Claim 29

The combination according to claim 18, wherein said sample and hold circuit includes a further diode connected in series with said common bus, a first amplifier connected in cascade with said further diode, said first amplifier including transistors arranged to provide at the output of said first amplifier the voltage Vn minus one diode voltage drop, a further amplifier, a normally off FET switch connecting said first amplfier in cascade with said further amplifier, said second amplifier being arranged to add one diode voltage drop to its input voltage, means for tuning said FET switch on in response to closure of any of said key switches, said sample and hold circuit having a configuration arranged to provide said voltage Vn at its output, said further amplifier including a hold capacitor connected across the input of said further amplifier.

Claim 30

The combination acording to claim 18, wherein the frequencies of saiD oscillators are independent of the voltage of said source of voltage connected to said one end of said chain.

Claim 31

An organ system, including a series resistance chain, composed of plurality resistances, a source of supply voltage connected to one end of said chain, a common bus, means for deriving from one point of said chain a voltage Vs, means for connecting junctions of said plural resistances to said common bus, each of said last means including a diode and a key switch connected between each of said junctions and said common bus, said diodes being poled conductively of said supply voltage, said resistances of said series resistance chain connected between said one point of said chain and said source of supply voltage having values such that a series of voltages Vn is provided at said junctions such that Vn-Vs vary with the frequencies of notes of the equally tempered muscial scale, a sample and hold circuit connected in cascade with said common bus, said sample and hold circuit being arranged and adapted to so compensate for any voltage drop through said diodes as to provide an output voltage equal to Vn, a multivibrator oscillator responsive to the difference of said last named voltage Vn and Vs to generate tone signals of said frequencies of the equally tempered muscial scale.

Claim 32

An organ system, including a series resistance chain, composed of plurality resistances, a source of supply voltage connected to one end of said chain, a common bus, means for deriving from one point of said chain a voltage Vs, means for connecting junctions of said plural resistances to said common bus, each of said last means including a diode and a key switch connected between each of said junctions and said common bus, said diodes being poled conductively of said supply voltage, said resistances of said series resistance chain connected between said one point of said chain and said source of supply voltage having values such that a series of voltages Vn is provided at said junctions such that Vn-Vs vary with the frequencies of notes of the equally tempered muscial scale, a sample and hold circuit connected in cascade with said common bus, said sample and hold circuit being arranged and adapted to so compensate for any voltage drop through said diodes as to provide an output voltage equal to Vn, a multivibrator oscillator responsive to the difference of said last named voltage Vn and Vs to generate tone signals of said frequencies of the equally tempered muscial scale.

Claim 33

The combination according to claim 24, wherein said oscillator is responsive to a current flow into said oscillator in response to and proportional to the voltage Vn-Vs and is independent of variations of voltage of said source of supply voltage and of the temperature of said diodes.

Claim 34

In an organ system, a voltage controlled tone oscillator, a voltage sample and hold circuit having an input and an output, means including key switches for generating a control voltage for said voltage controlled tone oscillator, plural diodes conductively connected between said means for generating a voltage and said input circuit, whereby plural diode voltage drops occur between said means for generating a voltage and said input circuit, said sample and hold circuit including means for adding diode voltage rises corresponding to said diode voltage drops between said input circuit and said output circuit, and means connecting said output circuit to said oscillator in control relation.

Claim 35

In an organ system, a voltage controlled tone oscillator, a voltage sample and hold circuit having an input and an output, means including key switches for generating a control voltage for said voltage controlled tone oscillator, plural diodes conductively connected between said means for generating a voltage and said input circuit, whereby plural diode voltage drops occur between said means for generating a voltage and said input circuit, said sample and hold circuit including means for adding diode voltage rises corresponding to said diode voltage drops between said input circuit and said output circuit, and means connecting said output circuit to said oscillator in control relation.