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公开(公告)号：US3849601A
公开(公告)日：1974-11-19
申请号：US40455473
申请日：1973-10-09
Applicant: MOTOROLA INC
Inventor： GONCHAROFF N
CPC classification number: H03G5/10 , H03G1/0023 , H04S7/307
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.
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公开(公告)号：BR7016688D0
公开(公告)日：1973-01-04
申请号：BR21668870
申请日：1970-02-11
Applicant: MOTOROLA INC
Inventor： GONCHAROFF N , JABBAR K
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公开(公告)号：BR7408326D0
公开(公告)日：1975-09-16
申请号：BR832674
申请日：1974-10-08
Applicant: MOTOROLA INC
Inventor： GONCHAROFF N
Abstract: 1461187 Volume and tone controlling circuits MOTOROLA Inc 25 Sept 1974 [9 Oct 1973] 41767/74 Headings H4R and H4J In a volume and tone controlling circuit an input signal at 12 is applied via a transistor 20 to the common terminal of a differential amplifier 14 and the division between the two halves of the differential amplifier is controlled by potentiometer 30 to control the output signal level from one half of the differential amplifier, at 28. The input signal is also connected to a tone control circuit 68 having two transistors 76 and 84. At the minimum setting of tone control potentiometer 69, transistor 76 is conductive, providing attenuation of the input signal at all frequencies. Movement of the control slider 72 from the minimum position causes transistor 76 to be cut off but high frequencies are still attenuated by capacitor 78, so that a bass boost is effected. Further movement of the slider 72 causes transistor 84 to become conductive, making capacitor 86 effective to provide top cut. As described a second differential amplifier 50 is connected parallel opposed with the gain control differential amplifier 14 as far as d.c. is concerned so that the d.c. level of the output at the point 56 remains constant with movement of the control potentiometer 30 to prevent d.c. changes introducing noise. The volume and tone control potentiometers are common to an identical circuit arrangement, not shown, to provide control of both channels of a stereophonic amplifier. A balance control 46 differentially varies the collector loads of the gain control differential amplifier arrangement in the two channels.
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公开(公告)号：BR7016032D0
公开(公告)日：1973-01-04
申请号：BR21603270
申请日：1970-01-14
Applicant: MOTOROLA INC
Inventor： GONCHAROFF N , JABBAR K
Abstract: 1293122 Automatic voltage regulation MOTOROLA Inc 7 Jan 1970 [15 Jan 1969] 711/70 Heading G3X [Also in Division H3] A circuit for tuning a plurality of resonant circuits 11, 18, 30 each including a voltage variable capacitor 14, 20, 31 has a reference voltage means 50 connected to a D. C. source B+ for providing different D. C. reference voltage outputs, such as 59 and earth, to different ones of the voltage variable capacitors and a variable control voltage 51 obtained from the D. C. source B+ supplies all of the resonant circuits so as to simultaneously tune the circuits such that the resonant circuits have a predetermined constant frequency offset established by the different reference voltage outputs. Zenor diode 54 stabilizes the D.C. output voltages from the bridge 50 and by making resistor 55 greater than 56 variation of the Zener voltage of diode 54 can be compensated. Silicon diodes 53 compensate for the effects of temperature on the Zener diode 54.
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