Matches 301 - 350 out of 366 < 1 2 3 4 5 6 7 8 >
Match Document Document Title
4101840 Volume control arrangement for an electro-acoustic system  
A volume control arrangement for an electro-acoustic system, said arranget having an adjustable amplification factor and a frequency characteristic dependent thereon, and comprising a frequency...
4085365 Earphone adapter for aircraft radios  
An adapter making it possible for the pilot of an aircraft equipped with a navigation-communication system whose audio output is permanently connected to a loudspeaker to hear well with ordinary...
4068092 Voice control circuit  
In a voice control circuit comprising a variable loss circuit and a voice level detector which is connected to control the variable loss circuit, there is provided a noise control circuit. The...
4041408 Push-pull audio amplifier system with muting  
Audio signals are equally power divided with the power divided signals being 180° out-of-phase. These separate out-of-phase signals are separately applied to the inverting input of separate...
4027112 Head-rest and loudspeaker combination  
A body of foam substance forming a head-rest, for example a head restraint for an automobile seat, an aircraft seat, or the like, provides a housing and support for the loudspeaker; the forward or...
4024535 Sound generating system for a sound masking package  
A self-contained sound masking package including a housing having an interior forming a loudspeaker enclosure in the bottom of which is disposed an electric circuit arranged to be connected to an...
4000370 Line level microphone with built in limiter  
A line level microphone. The microphone includes an amplifier and a peak limiter variably shunting the input of the amplifier to substantially avoid distortion or clipping of the microphone output...
3939451 Balance control for use in 4-channel stereophonic system  
A balance control comprises a box-type frame, a plurality of variable resistors individually mounted on each side wall of the frame, the upper plate of the frame having a large hole, a pair of...
3914705 Control circuit with field effect transistors of a gain control amplifier  
A first one of plural field effect transistors formed in a semiconductor chip is used as a control field effect transistor operatively coupled to a gain control amplifier and acting as a variable...
3893038 Automatic gain control circuit  
An automatic gain control circuit for a stereo amplifier having separate gain control means in each channel, each gain control means being actuated by control signal means from the same channel and...
3819957 TWO CHANNEL BALANCE CONTROL DEVICE  
A signal level control device for varying the level of an input signal through the variation of a variable resistor. A switching circuit is turned ON for a period of time determined by the...
3796945 DIGITAL ATTENUATOR WHEREIN TRANSISTOR SWITCH MEANS ARE BIASED BY RECTIFIER CIRCUIT  
The disclosure describes a digital attenuator having non-isolated, L-type attenuator sections. The sections comprise shunt legs that are switched to ground potential by bipolar NPN transistors. An...
3784746 SINGLE ACTUATOR FOR EFFECTING MULTIPLE CONTROLS  
A control actuator in a first mode of displacement is shifted longitudinally along a predetermined axis to effect a first form of control to blend the sound for a stereo high fidelity sound system....
3760102 LEVEL SETTING IN NOISE REDUCTION SYSTEMS  
A special test tone at a predetermined level is recorded or transmitted to enable the level to be set correctly on playback or reception. To enable the tone to be identified, it is intermittently...
3699453 BI-DIRECTIONAL OPERATING MECHANISM  
A touch-operated volume control device in which a potentiometer is adjusted by depressing either end of a deflectable key. The volume is increased, progressively, by repeatedly depressing one...
3668323 AUTOMOTIVE VEHICLE SOUND DISTRIBUTION SYSTEM  
In an automotive vehicle, a relay is manually operable to shift control over the sound level of a rear seat speaker from a front seat fader exclusively to a rear seat fader and the front seat fader...
3629775 STEREO BALANCE AND FADER POTENTIOMETER  
A voltage and/or impedance control for simultaneously adjusting a number of circuits or electrical components finding useful application in a number of environments, including the provision of a...
3536861 HEARING AID CONSTRUCTION  
3446976 TELEPHONE OPERATED OPTOELECTRONIC VOLUME CONTROL  
3260954 Fader amplifier including a differential gain control mechanism  
3260952 Fader amplifier comprising variable gain transistor circuits  
3243511 Amplifier circuit  
3195067 Frequency compensated gain control circuit  
3055990 Hearing aid  
3020343 Audio selective fading system  
2987584 In-ear hearing aid  
2983797 Hearing aid  
2971065 Ear insert hearing aid  
2952748 Binaural eyeglass hearing aid construction  
2848539 Audiometer  
2824177 Hearing aid amplifier  
2783457 Voltage selection and indication  
2692305 Hearing and unit  
2520732 Sound amplifier muting means  
2515111 Electronic fade-in control system for phonographic reproduction or the like  
2511085 Cuing control for audio circuits  
2500301 Molded chassis for hearing aid apparatus  
2444302 Hearing aid  
2424243 Remote control system  
2389987 Apparatus for communication systems  
2336828 Portable microphone and amplifier  
2309109 Microphone  
2298618 Sound reproducing system  
2286540 Television system  
2253186 Sound characteristic control  
2226836 Interference-reducing system  
2207821 Sound picture apparatus  
2193428 Wired news disseminating system  
2184565 Sound picture apparatus  
2183389 Indicating circuit  
Matches 301 - 350 out of 366 < 1 2 3 4 5 6 7 8 >