US3849601A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Volume and tone controls for multichannel audio systems
Assignee: Motorola Solutions Inc
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Filing: 1973-10-09
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Granted: 1974-11-19
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Expires: 1993-10-09
Abstract
Abstract A single volume control and a single independent tone control set a plurality of audio channels. Each channel contains a gaincontrollable differential amplifier operated as small-signal amplifier, driven by a constant-current source transistor which also accepts the input audio signal. Gain is varied by altering the DC bias on one of the differential amplifier elements. However, such variation causes noise which is cancelled by a second differential amplifier connected in parallel with the first, but oppositely Phase d. Tone is varied by shunting the input with capacitors in series with a pair of oppositely conducting transistors which function as level-controlled resistors.
Inventors
- 👤 N Goncharoff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:48
CPC Classifications
H; H03; H03G; H03G5/00; H03G5/02; H03G5/04; H03G5/10; H03G1/00; H03G1/0005; H03G1/0017; H03G1/0023; H04; H04S; H04S7/00; H04S7/30; H04S7/307
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
368 words
In an audio signal translating system including a differential amplifier having first and second transistors, one of the transistors being connected to an output terminal, a signal translating transistor component including an input and output, the output thereof being connected to the first and second transistors of said differential amplifier for applying operating current and simultaneously an audio signal path thereto, an audio signal input means coupled to the input of said signal translating transistor to provide an input signal thereto, settable volume control means coupled to said differential amplifier a predetermined portion of said audio signal being passed by said differential amplifier to said output terminal in accordance with the setting of said volume control means, a tone control circuit connected to said input of said signal translating transistor for diverting predetermined frequency components of said audio signal therefrom to adjust the tonal quality of the audio signal passed to said output terminal, said tone control circuit including in combination; tone control selector means coupled to a source of power, first and second transistor means coupled electrically to said tone control selector means and capacitor means, said tone control selector means being movable to a first setting for providing a first predetermined voltage for rendering a first one of said first and second transistor means conductive, whereby high and low frequency components of said audio signal are diverted from said signal translating transistor through said first-mentioned transistor means, to provide a relatively flat frequency response to said audio output, to a second setting for providing a second predetermined voltage to render said first transistor means cut off, whereby high frequency components of said audio signal are diverted from said signal translating transistor through said capacitor means to provide a bass boost to said audio output and to a third setting for providing a third predetermined voltage for rendering said second transistor means conductive while maintaining said first transistor means cut off, whereby additional high frequency components of said audio signal are diverted from said signal translating transistor through said second transistor means while also diverting other high frequency components of said audio signal through said capacitor means, to provide a treBle cut effect to said audio output.
Claim 2
Dependent Claim
368 words
In an audio signal translating system including a differential amplifier having first and second transistors, one of the transistors being connected to an output terminal, a signal translating transistor component including an input and output, the output thereof being connected to the first and second transistors of said differential amplifier for applying operating current and simultaneously an audio signal path thereto, an audio signal input means coupled to the input of said signal translating transistor to provide an input signal thereto, settable volume control means coupled to said differential amplifier a predetermined portion of said audio signal being passed by said differential amplifier to said output terminal in accordance with the setting of said volume control means, a tone control circuit connected to said input of said signal translating transistor for diverting predetermined frequency components of said audio signal therefrom to adjust the tonal quality of the audio signal passed to said output terminal, said tone control circuit including in combination; tone control selector means coupled to a source of power, first and second transistor means coupled electrically to said tone control selector means and capacitor means, said tone control selector means being movable to a first setting for providing a first predetermined voltage for rendering a first one of said first and second transistor means conductive, whereby high and low frequency components of said audio signal are diverted from said signal translating transistor through said first-mentioned transistor means, to provide a relatively flat frequency response to said audio output, to a second setting for providing a second predetermined voltage to render said first transistor means cut off, whereby high frequency components of said audio signal are diverted from said signal translating transistor through said capacitor means to provide a bass boost to said audio output and to a third setting for providing a third predetermined voltage for rendering said second transistor means conductive while maintaining said first transistor means cut off, whereby additional high frequency components of said audio signal are diverted from said signal translating transistor through said second transistor means while also diverting other high frequency components of said audio signal through said capacitor means, to provide a treBle cut effect to said audio output.
Claim 3
Dependent Claim
79 words
An audio signal translating system as claimed in claim 1 wherein said first and second transistor means are of opposite conductivity, wherein each said first and second transistor means includes first and second electrodes and wherein said tone control selector means includes variable resistance means coupled between a source of power and the first electrodes of said first and second transistor means, the second electrodes of said first and second transistor means being coupled to said signal translating transistor.
Claim 4
Dependent Claim
94 words
An audio signal translating system as claimed in claim 2 wherein said tone control circuit further includes noise suppression means interposed electrically between the first electrode of the first one of said transistor means and said tone control selector means for suppressing noise due to the mechanical movement of said variable resistance means, said noise suppression means including a combination resistance means and capacitor means coupled in parallel electrical relation with respect to each other, the combination being connected in series with said first electrode of said one transistor and said variable resistance means.
Claim 5
Dependent Claim
135 words
An audio signal translating system as claimed in claim 1 wherein the output from said differential amplifier is taken at the collector electrode of a first one of said first and second transistors thereof, wherein said system further includes a second differential amplifier connected in parallel relation with said first-mentioned differential amplifier, said second differential amplifier also being connected to said settable volume control means and wherein the collector of the second transistor of said second differential amplifier is connected to said output terminal so that an output signal is taken therefrom which is out of phase with the signal taken from said first differential amplifier, whereby the level of the output signal at said output terminal is maintained substantially constant to eliminate mechanical noise due to the movement of said settable volume control means.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |