Abstract: A resistance microphone for a toy telephone mouthpiece includes a pair of circularly bored cylindrical carbon cups secured to a plastic sheet diaphragm in opposed spaced apart relationship and a cylindrical carbon rod having two conical ends held loosely in the cups. Holes are provided in the diaphragm on opposite sides of the cups and wires are wrapped around the cups, in annular grooves in the cup peripheries, threaded through the openings and twisted onto themselves to both secure the cups to the diagram and to provide contact leads for the microphone.

Abstract: An attendant board system in a telephone exchange in which when the direct connection type attendant board system is desired in connecting the office trunk and the attendant trunk, the office trunk and the attendant trunk are connected with each other directly, while when the channel access type attendant board system is desired, the office trunk and the attendant trunk are connected with each other through a channel switch frame. This change in the connection mode is performed by plugging in a direct connection type office trunk or a channel access type office trunk.

Abstract: In an amplification system comprising an amplifier, a loudspeaker, normally open contacts connected in series between the amplifier and the speaker, and a power supply for the amplifier having relatively long buildup and decay times of its output voltage in response respectively to the connection and disconnection of the power supply to and from the a.c. line, means are provided responsive to the connection of the power supply to the a.c. line for delaying the closing of the normally open contacts until after the power supply voltage has built up to its full operating potential for eliminating the transient audio signals from the amplifier associated with power supply voltage buildup from being reproduced by the loudspeaker. Means are also provided for opening the contacts quickly after the power supply is disconnected from the a.c. line for eliminating the distorted audio signals from the amplifier associated with power supply decay from being reproduced by the loudspeaker.

Abstract: A device having an analog storage for storing in real time an electric analogue signal proportional to vocal tract resonance periods within speech pitch periods of speech in gas in deep sea diving. A clock is used for providing clock pulses proportional to the depth at which the speech is being made for clocking the analog signal into the analog storage device. A second clock is used for clocking the speech out of the analog storage device at that frequency corresponding to normal voice.

Abstract: An electronic tone ringer for use in telephone subsets. Operating in response to and powered from incoming received ringing signals, the ringer circuitry provides audible multitone signals. The circuitry employed eliminates so-called "bell tapping" or "chirping" during dialing.

Abstract: A telephone amplifier circuit comprising a transmit amplifier and a receive amplifier provides gain in both the transmit and the receive directions. Loss is voice-switched into the receive amplifier in response to the sum of the transmit and receive speech levels to provide sidetone and gain control.

Abstract: A method and apparatus for counting a large number of events by storing in a register a smaller number statistically related to the large number.An estimate v is stored representing the actual number of events n according to a logarithmic relationship. The register is updated only if (1) an event occurs to be counted and (2) a random number r obtained from a sample with uniform distribution over the interval 0,1 is less than ##EQU1## WHERE A IS A NUMERICALLY DERIVED PARAMETER CONTROLLING THE SIZE OF THE EVENT COUNT.

Abstract: A miniature unidirectional condenser microphone includes a diaphragm dividing a housing into first and second chambers. Each chamber communicates through a sound inlet port to the atmosphere. One of the sound inlet ports is covered by a sheet of porous, non-absorbent, hydrophobic thermoplastic material forming an acoustical resistance.

Abstract: The present invention relates to an analysis device, for use in a transit exchange for transmission of asynchronous data signals with known character structure and known nominal signalling rate. The character structure comprises a start pulse and a number of data pulses which are sampled in the exchange by means of sampling pulses in synchronism with clock pulses from a clock pulse source several times per data pulse for the establishment of the binary informational content of the data signals. The device includes means through the aid of which a summation is made of the clock pulse occurring during a data pulse with indication signals being delivered at specific clock pulse positions within the data pulse.

Abstract: A signal interpreting system for frequency-selective multi-frequency tone dialing includes a code tester and a code converter, and two serially connected delay means processing the output of said code tester and having an output controlling logic circuitry arranged in the output circuits of said code converter.

Abstract: There is disclosed herein an improved dial assembly suitably adapted to provide an expanded capability for a touch-tone telephone system or to replace existing rotary dial assemblies in various equipment manufacturers' subsets with a touch-tone like assembly. In particular the improved dial assembly includes an upper frame and a pushbutton arrangement similar to known touch-tone dial assemblies. Longitudinal and transverse rods positioned in separate planes immediately below the upper frame convert the downward movement of a particular depressed button into rotational movement. The rotational movement of the rods is utilized by suitably positioned cooperating sets of switches to connect in the necessary manner the various telephone circuits within and/or external to the particular subset. The improved dial assembly above expands the capability of present day assemblies in that it enables the provisioning of ancillary telephone functions, such as repertory dialing, toll restricting circuitry, etc.

Abstract: Two-way links communication capability between time-division multiplexed subsystems is provided via dual time division address and data busses correlated by a recirculating memory having sections respectively associated with the address busses. Addresses on the address busses are recognized by the individual subsystems and further decoded to gate data to and from the busses data according to time slots assigned to terminal devices in the subsystems. The dual bus arrangement provides a full-duplex link in the sense that there is simultaneous communication via the two data busses, one each way.

Abstract: A plurality of remote terminals are each connected to different pluralities of gas or electric meters or the like which are close together such as in an apartment building complex. The remote terminals communicate with a central terminal over a single public telephone line. The central terminal transmits an interrogation signal to the remote terminals over the telephone line, which then transmit the meter readings over the telephone line to the central terminal for recording.

Abstract: Sound signals are created at the eardrums of a listener to correspond to sound signals which would be created at the eardrums of the listener in a predetermined acoustical environment in response to first electrical signals applied to a loudspeaker having known sound-reproducing characteristics. A determination of the relative position of the head of the listener when the listener is in the predetermined acoustical environment is made, producing a second signal. An equalizing network is provided with a first input for receiving said first electrical signals, and a second input for receiving the second signals, and a pair of outputs connected to the earphones on the headset of a listener.

Abstract: A data terminal is connected to a telephone line for data transmission and reception. When a malfunction is detected in the data terminal, the data terminal is automatically disconnected from the telephone line and a telephone set connected to the telephone line. After a predetermined time interval, the telephone set is automatically disconnected from the telephone line and the data terminal re-connected to the telephone line.

Abstract: A changeable exhibitor incorporating a timing device displays, as a function of time indicating intervals, a direct visual readout of the telephone charges for a direct dial call between any two points in the continental United States.

Abstract: A sound reproducing device comprising a first (low frequency) speaker and a second (high frequency) speaker, the high frequency speaker mounted within its own housing which allows rear-cone radiation out the housing sides, in addition to front-cone radiation out the front, thereby improving radiation efficiency and transient response.

Abstract: A battery saving system for a portable duplex communications system such as a portable telephone system includes a voice operated transmitter within each portable unit which automatically transmits radio signals upon application of audio signals thereto and discontinues transmission upon termination of the audio signals to conserve battery power. A companion receiver includes a fast acting squelch system to substantially eliminate the noise bursts occurring between transmissions by said portable unit.

Abstract: Successively larger fractions of a first composite signal are compared with an entire second composite signal to obtain control signals. The composite signals comprise similar direct components with push-pull a-c signals superimposed thereon. One of these control signals may be used to standardize the average amplitude of the push-pull signals by causing them to be attenuated when they exceed a given amplitude, and at least one other, for controlling the synchronous regeneration of the a-c signals. The invention is useful for PCM repeaters in telephone cables.

Abstract: A multi-frequency receiver is provided as part of a system able to evaluate the presence of 2 out of 5 signals and which incorporates 5 channel paths each including a parallel resonant circuit each of which is tuned to a distinct one of the frequencies of the 5 signals. In each channel path a first and second detection circuit is coupled to the corresponding resonant circuit and reacts when the voltage at the coupling point is larger than a respective common first or second threshold voltage, the second of which is larger than the first one. When spurious signals are received, at least one of the first detection circuits will react and the 2 out of 5 evaluation circuit is blocked. When a second detection circuit in a channel path reacts, the effect of the first one in this channel path is inhibited. Only signals having a well determined frequency combination are evaluated.