US3558796A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Touch percussion for electronic organ with back-to-back diode gates
Assignee: Baldwin Piano and Organ Co
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Filing: 1968-11-13
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Granted: 1971-01-26
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Expires: 1988-11-13
Abstract
Abstract An electronic organ system in which tone signals deriving from percussive voice tabs are passed through a slow percussive linear diode gate to an amplifier and loudspeaker. The percussive voices are provided by either percussive gates or key switches individual to tone sources and have relatively fast decays following release of key switches. The individual percussive gates remain open while key switches are closed. The slow percussive gate is common to all the percussive voices and is either (1) normally open and gradually closed during any tone or (2) is normally closed and is rapidly opened and then gradually closed in response to onset of any tone regardless of whether other tones are then present, by means of a novel gating wave generator. The system utilizing percussive gates as tone generators is particularly useful in simulating piano tones since if a key is held down a long sustain results, which cuts off fairly rapidly if the key is released, but which is percussive, if a key is actuated staccato, with a short sustain.
Inventors
- 👤 Michael R Harris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:55
CPC Classifications
G; G10; G10H; G10H1/00; G10H1/02; G10H1/04; G10H1/053; G10H1/057
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
136 words
A percussion circuit, including: an array of tone signal sources each connected to a bus via a separate percussive gate having a relatively rapid decay rate; a load circuit; a further percussive gate connected between said bus and said load circuit, said further percussive gate having a relatively slow decay rate, said further percussive gate including; back-to-back diodes connected in series between said bus and said load circuit; means DC isolating said diodes; a coupling capacitor connected between said diodes for solely AC coupling said diodes; means maintaining AC current flow from said bus into said further percussive gate below about 25 mv; and means separately biasing said diodes in response to a gating current wave which decreases gradually as a function of time from not more than 50. Mu a to substantially 0. Mu a.
Claim 2
Dependent Claim
136 words
A percussion circuit, including: an array of tone signal sources each connected to a bus via a separate percussive gate having a relatively rapid decay rate; a load circuit; a further percussive gate connected between said bus and said load circuit, said further percussive gate having a relatively slow decay rate, said further percussive gate including; back-to-back diodes connected in series between said bus and said load circuit; means DC isolating said diodes; a coupling capacitor connected between said diodes for solely AC coupling said diodes; means maintaining AC current flow from said bus into said further percussive gate below about 25 mv; and means separately biasing said diodes in response to a gating current wave which decreases gradually as a function of time from not more than 50. Mu a to substantially 0. Mu a.
Claim 3
Dependent Claim
30 words
The combination according to claim 1, wherein: said further percussive gate is normally open; and means responsive to presence of signal on said bus for generating said gating current wave.
Claim 4
Dependent Claim
36 words
The combination according to claim 1, wherein: said further percussive gate is normally closed; and means responsive to each initiation of conductivity of any one of said separate percussive gates for generating said gating current wave.
Claim 5
Dependent Claim
107 words
Gating circuit for musical tone signals, comprising: a first diode; a second diode; a coupling capacitor connecting said diodes in a series circuit; means applying musical tone signals to said series circuit; means deriving musical tone signals from said series circuit; first resistive means DC isolating said diodes from each other and applying separate substantially identical gating waves to corresponding electrodes of both said diodes; second resistive means connecting the remaining ones of said electrodes to ground; and said first resistance means being arranged to limit diode bias current to less than 50. Mu a peak, the applied musical tones having peak amplitudes of less than 25.ma.
Claim 6
Dependent Claim
107 words
Gating circuit for musical tone signals, comprising: a first diode; a second diode; a coupling capacitor connecting said diodes in a series circuit; means applying musical tone signals to said series circuit; means deriving musical tone signals from said series circuit; first resistive means DC isolating said diodes from each other and applying separate substantially identical gating waves to corresponding electrodes of both said diodes; second resistive means connecting the remaining ones of said electrodes to ground; and said first resistance means being arranged to limit diode bias current to less than 50. Mu a peak, the applied musical tones having peak amplitudes of less than 25.ma.
Claim 7
Dependent Claim
142 words
A gating system, comprising: a transistor switch having a first terminal providing voltage at two discrete levels with respect to ground selectively; a timing capacitor having one terminal connected to ground and having a further terminal; and a diode and a timing resistance connected in parallel and both connected between said first terminal and said further terminal, said diode being poled to conduct current into said capacitor while said voltage is at the higher of said two discrete levels, a linear diode gate responsive to the voltage across that capacitor, said linear diode gate including back-to-back diodes separated by a coupling capacitor connected in series between a tone signal source and a load circuit, and separate current limiting resistances connected between said capacitor and said diodes, said resistances being selected to limit bias current in said diodes below 50. Mu a peak.
Claim 8
Dependent Claim
142 words
A gating system, comprising: a transistor switch having a first terminal providing voltage at two discrete levels with respect to ground selectively; a timing capacitor having one terminal connected to ground and having a further terminal; and a diode and a timing resistance connected in parallel and both connected between said first terminal and said further terminal, said diode being poled to conduct current into said capacitor while said voltage is at the higher of said two discrete levels, a linear diode gate responsive to the voltage across that capacitor, said linear diode gate including back-to-back diodes separated by a coupling capacitor connected in series between a tone signal source and a load circuit, and separate current limiting resistances connected between said capacitor and said diodes, said resistances being selected to limit bias current in said diodes below 50. Mu a peak.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |