Abstract: A pneumatic speech simulator has a vibratory tone-generating element which produces an audible tone in response to the flow of pressurized air within a predetermined pressure range, said tone being transmitted to a patient's pharyngeal region by a conduit, such as a nasal catheter. The simulator includes a pressure compensation valve, upstream from the tone-generating element, which maintains the pressure experienced by the tone-generating element within its operating range as the pneumatic resistance of tone-transmitting conduit is increased due to partial or total blockage.

Abstract: A pulse position modulated (PPM) signal is derived from an input FM signal, and first and second switching signals are derived which are opposite in phase and correspond to alternating half cycles of the PPM signal. First and second opposite phase subcarrier signals are derived synchronized to the pilot signal in the input FM signal, and various combinations of the switching and subcarrier signals are multiplied together and the multiplication products combined to obtain left and right channel outputs.

Abstract: A test set designed for testing meter reading units as well as telephone line connections for automatic utility meter reading systems. The test set is capable of simulating the meter reading apparatus when testing the telephone line and of simulating the telephone line when testing the meter reading components. The test set further simulates the receiving apparatus in the central office to test the combination of the meter reading apparatus and the telephone line. The test set is self powered by batteries or may be powered from conventional AC outlets. The test set is operative both in the telephone plant and in the field.

Abstract: A communication system includes a device connected to a line through a hybrid coil and performing the transmission/reception of data and voice from and/to an opposite device. A switching relay of a voice transmission/voice reception in the device is controlled by a control data from the opposite device. The control data is sent out a plurality of times and after detection in a data detecting portion, a continuous transmission check is made in a continuous transmission checking portion. In the device, a connection of data detecting portion and the line and a connection of a microphone and the line are alternately disconnected by a relay, so that a detection of data is made only when the transmission of voice is interrupted. The disconnecting relay is driven in response to a pulse of a predetermined duty ratio.

Abstract: An improved radiotelephone includes a unique microprocessor and peripheral devices for controlling the operation of portable or mobile radio transceivers in a cellular-type radiotelephone system. The microprocessor is coupled by a data interface unit and synchronization unit to the radio transceiver for transmitting and receiving Manchester-coded supervisory signalling having a 10 KHz bit rate. The microprocessor is also coupled by a unique self-clocking serial data bus and unique interface adapters to the radio transceiver for controlling the operating frequency, audio signals and transmitted RF signal thereof, to a keyboard for sampling the keys thereof, an off-hook switch and display for displaying telephone numbers, and to serial number and telephone number memories for accessing the stored serial and telephone numbers assigned to the radiotelephone.

Abstract: An amplitude limiter for an AM broadcast transmitter to minimize energy in the broadcasted signal outside an allocated broadcast bandwidth. The secondary and higher order spectra (i.e. second and higher harmonics) of a broadcasted AM stereophonic signal are minimized by limiting the amplitude of the audio signal, prior to modulation onto the carrier, within a predetermined portion of the audio frequency range. This is achieved by controlling the gain of the audio signals in that predetermined portion as a function of the level of a submodulation component also within that predetermined portion of the audio frequency range.

Abstract: An alarm system used in a home or office for determining when the consumption of oil or other utility in a tank has been depleted to a predetermined alarm level, and automatically telephoning a computer located at the utility company's office to report the alarm and request delivery of fuel. A pump run count is calculated corresponding to the number of cycles of electricity required to pump a given amount of fuel down to a predetermined alarm level in the tank. As fuel is displaced by the pump, a counter is advanced until it reaches the pump run count whereafter an alarm is activated to cause the alarm system to automatically seize the customer telephone service and dial the computer at the utility office for requesting delivery of fuel oil. The system eliminates the human intervention for reading meters and calling the fuel oil company over the telephone to place an order for delivery.

Abstract: In a system for transmitting a charging signal from an exchange to a telephone system together with a voice signal, radio equipment in the exchange side detects the charging signal sent from the exchange and encodes it into a pulse code signal comprising a plurality of continuous pulses. Thereafter, this pulse signal is modulated into a frequency signal outside the voice transmitting frequency band and then transmitted as a radio signal after it is superimposed on the voice signal. Radio equipment on the telephone side detects this charging signal carrier and demodulates it into the pulse code signal, then counts it and transfers the charging signal when the counted value reaches a specified value.

Abstract: An FM stereophonic radio broadcasting system in which stereophonically related audio frequency source signals L and R are matrixed to obtain stereophonic sum and difference signals M and S, respectively. At the transmitter, the difference signal, is compressed, and the conventional difference signal and the compressed difference signal modulate respective quadrature-related sub-carriers of the same frequency to develop two double-sideband, suppressed-carrier signals, the frequency of the sub-carriers being sufficiently high as to assure a frequency gap between the lower sidebands of the modulated sub-carrier signals and the sum signal M. The M signal, the aforementioned suppressed-carrier signals, and a pilot signal having a frequency which lies within the frequency gap, are combined and frequency-modulated onto a high frequency carrier for the purpose of transmitting the same to one or more remote receivers.

Abstract: In a cordless, head mounted telephone set a means of powering the radio transmission and reception unit and selecting telephone lines is provided by ganging the power and selecting switch thereof to the rotation of the microphone mouth piece.

Abstract: An apparatus for driving n transducer units (n>1), each comprising one or more electro-acoustic transducers, comprises m signal inputs (m.gtoreq.1) for connecting m signal sources to the apparatus. Each signal input is connected to an associated amplifier unit and there are n signal outputs to which said transducer units may be connected. A signal input is connectable to one or more of the signal outputs via the associated amplifier unit. The apparatus further comprises k auxiliary amplifier units (k.gtoreq.1) with one or more of said auxiliary amplifier units being connectable in parallel with an arbitrary amplifier unit so that the total power of the apparatus may be reduced substantially.

Abstract: A cordless musical extension telephone unit with programmable capabilities, wherein a singular or a plurality of respective data block relevant to future phone calls to be made can be entered into its micro-computer's memory so that, according to the sequence of programmed time and/or data when each respective phone call becomes due, as coordinated with the forward progression of actual time and date, the integrated alarm system can effectively remind the user to make the respectively pre-programmed phone call without delay, while the relevant block of information about the current targeted call becomes automatically displayed at the LCD or LED display window.

Abstract: A method for processing the audio signal in a loudspeaker system prior to delivery to the loudspeaker and the apparatus for such processing is disclosed. Uniform acoustic output with respect to frequency at frequencies below the resonant frequency of the loudspeaker system is achieved by changing the strength of the signal at a constant rate in inverse proportion to audio signal frequencies from a frequency below the resonant frequency to a frequency at least one octave above the resonant frequency. A method and apparatus for limiting the audio signal to prevent distortion is also disclosed.

Abstract: A sound detecting device for amplifying distant or weak sounds, including a novel loud sound suppressing circuit for temporarily shunting the amplifier input signal to ground whenever the amplifier output signal exceeds a predetermined amplitude. The microphone, amplifier, and sound suppressing circuit are mounted in a wand shaped much like a flashlight. The wand can be attached to headphones.

Abstract: A power line telephone extension system for carrying electrical signals between a subscriber's telephone line of a conventional telephone communication system and the subscriber's remote transmit-receiver device, (such as a conventional extension telephone), over the AC electric power wires available to the subscriber which includes: master linking circuits for processing signals between the subscriber's telephone line and the AC power wires; extension linking circuits for processing signals between the AC power wires and the subscriber's remote transmit-receive device, such as a conventional extension telephone; and a directional coupler circuit electrically coupling the remote transmit-receive device and the telephone line. The extension system is quite suitable for use with the presently available, well known, conventional extension telephone that plugs in by the plug (modular or 4 prong) provided therewith, to the directional coupler.

Abstract: There is disclosed a thermal printer with memory to memorize pattern information which has previously been printed by a thermal head, a converter connected to the memory and to convert the pattern information memorized in the memory into time information, and a device connected to the converter and to cause new pattern information to be printed by the thermal head on the basis of the timing signal to be obtained from the converter.

Abstract: A sound reproduction system with an improved audio mixing console provides means for instantaneous recordation of the positions of control elements on modules of the mixing console. Means are also provided for recalling the recorded positions and indicating to the sound engineer the recorded positions by use of a pair of light-emitting diodes adjacent to each control element on the console.

Abstract: A technique for reducing the nonlinear frequency characteristics of a carbon granule microphone of the type generally used in telephone handsets wherein a tone outside the voice range is applied to the microphone simultaneously with the audio signal desired to be transmitted. This technique has particular advantages with telephone modems, especially those where the sending and receiving frequencies are hamonically related.

Abstract: In a cellular mobile telecommunication system, a method and apparatus for controlling the process of locating a mobile unit from the cell sites. When a mobile unit goes beyond the radio range of its associated controlling cell site, that cell site sends a message to nearby cell sites to measure and report the strength of the received signal from that mobile on each of their directional antennas and to report radio channel availability. These reports are returned to the controlling cell site which compares the received signal strength mesurements against stored thresholds. The controlling cell site generates and transmits to the mobile telecommunications switching office (MTSO) a hand-off request message including a list of candidate hand-off cell sites and directional antennas. The MTSO then selects an available channel associated with one of the candidate cell sites and antennas and generates a sequence of messages to hand-off communications control from the controlling cell site to a candidate cell site.

Abstract: Method and apparatus for automatically controlling exposure of a photographic film by evaluating non-visible spectral scene light frequencies. Particularly for artificially lit scenes, an evaluation of predominantly infrared frequencies is preferred. In one embodiment, the IR scene lighting is evaluated under control of the shutter aperture system while in another embodiment, the strobe itself is controlled by its own photodetector responsive to IR scene light.