Abstract: The service area of the system is divided into a plurality of overlapping radio zones and a mobile-system base station is installed in each zone. The mobile-system base stations are assigned with a common control channel and each station is assigned with a plurality of speech channels which are commonly controlled by the control channel. Where a mobile body originates a transmission, the intensities of signals received by respective stations which have resulted from a signal transmitted by the mobile body are compared so as to designate an idle speech channel of a station which has received a signal having the maximum intensity among mobile-system base stations including the idle speech channel.

Abstract: A telephone ringing extender is shown which includes a ringing signal detector and a switch. In response to ringing signals, the ringing extender grounds the tip conductor to operate telephone ringers bridged on the loop. Protection against excessive voltages and excessive currents is also provided.

Abstract: A device for maintaining a constant distortion output from a musical instrument amplifier over a volume range of the musical system. The amplifier is set at a predesired volume setting and volume control is provided by a potentiometer control interposed between the output of the amplifier which may, for example, be a guitar amplifier, and the loudspeaker. The potentiometer is connected so that one end is in series with the speaker providing the primary means for controlling volume while the other end is in parallel with the speaker. Because the load that the amplifier sees is a function of both the speaker impedance and the potentiometer setting, there is a calibration scale associated with the control dial of the potentiometer so that the amplifier output impedance can be matched to the impedance of the speaker being used.

Abstract: A speech analyzer is provided for determining the emotional state of a person by analyzing pitch or frequency perturbations in the speech pattern. The analyzer determines null points or "flat" spots in a FM demodulated speech signal and it produces an output indicative of the nulls. The output can be analyzed by the operator of the device to determine the emotional state of the person whose speech pattern is being monitored.

Abstract: This circuit utilizes the customer's own tip and ring lines to allow the customer selectively to transfer incoming calls from a primary equipment location (e.g. a primary telephone) to an auxiliary equipment location (e.g. answering bureau). A manually operable, double throw switch on the customer's premises is connected to the loop of the customer's primary phone, and in one position connects the primary loop directly to the associated telephone company's COE (central office equipment). In its other position the switch allows current leakage in at least part of the primary loop, and a sensing network effects energization of a transfer relay if the leakage current is sufficient and flows in the proper direction. The energized relay transfers the COE to the customer's auxiliary equipment location. Slave circuits controlled by the transfer relay may effect transfer on a multitude of central office lines. The transfer on each loop is only activated when the loop is idle.

Abstract: The lines or stations of a multi-line office telephone system are sequentially examined to detect a hold tone signal of a specified frequency or frequencies on one or more of the lines. The lines are examined for increasingly longer time periods in accordance with the type of energy sensed at each line. If the line is not active or connected in a first brief period, the scanner then proceeds to examine the next line for a hold tone signal. If wide-band energy is not detected on the line in a second, longer period, the examination of the line is terminated and the scan process is continued to the next line. If wide-band energy above a threshold is detected on the line in a third, still longer period, the detected energy is further examined to determine whether this energy includes a valid hold tone signal. If a hold tone signal is detected on a line, the line is scanned again to detect the removal of the hold tone signal therefrom, whereupon a hold status is assigned to the line.

Abstract: A centrally located processing unit controls the use of long-distance communication circuits and records the use of the circuits. The centrally located processing unit selects the least expensive telephone line available and instructs the remote satellite to thereby insure the optimum use of bulk rate communications lines. Where no desired bulk rate communication facility is available, a user enters a call-back number into the processing unit and is called back at that number when the facility becomes available.

Abstract: A headset having an ear cup with a beveled spherical socket hole which rotatably supports and seats a spherical boom support swivel. The swivel consists of two half ball elements held in registration on an asymmetrical boom through gripping action of an asymmetrical hole in each of the half ball elements. Opposing ramp projections and sockets in the half ball elements bias the half ball elements in opposing rotational motion about the boom axis when the half balls are urged toward each other by a floating spring retainer plate thus producing a torque on the boom which is tightly gripped by the opposing half ball elements. Opposing outward projections on the boom mate with depressions in the half ball elements to prevent longitudinal sliding of the boom opposite the swivel and adjacent the operator's mouth. The swivel is rotatably held in the beveled spherical socket hole by the floating spring retainer plate having a flanged dish forming a ball seat swivel.

Abstract: The cathode of the gas-discharge devices performing the distributor function for associated sparkplugs have lateral extension flanges approaching closely to the insulating envelopes of the devices. A grounded control electrode just outside the gas-discharge device is moved from a rest position to an operating position aligned with and adjacent to the cathode extension flange by an electromagnet operated by a transistor circuit in accordance with the cylinder firing order of the engine.

Abstract: A microphone assembly is adaptable to righthand or lefthand operation by having a reversibly positionable pushbutton. The microphone housing has two oppositely located apertures for receiving the pushbutton. The aperture not used is covered with a part of a reversibly positionable shroud. The pushbutton is a lever which pivots about a pin and activates a spring loaded leaf spring switch, the switch being operable from two opposite directions by the reversibly positionable pushbutton lever.

Abstract: A time division multiplex transmission system including a central unit and a plurality of terminal units connected through a single pair of bus lines to the central unit. The central unit transmits at least a set of address and control signals sequentially to the respective terminal units and also an electric power required for operating and controlling the respective terminal units at least accompanying the address and control signals. The respective terminal units include a condenser for accumulating the electric power from the central unit so that each terminal unit corresponding to each address signal from the central unit performs any desired operation with the accumulated power and transmits a response signal depending on a result of the operation to the central unit responsive to the control signal.

Abstract: A circuit for detecting ringing signals on a telephone line in which the alternating voltage oscillations are converted to direct current pulses which are used to charge a first capacitor. Only signals of 14 hertz or above are sufficient to repetitively charge the first capacitor to a high enough voltage to open continuously a grounding circuit through a comparator, thus, allowing a second capacitor to charge up and open a second grounding circuit thus permitting current to flow to a suitable output. The output is used to activate lights on the telephone which lights are either flashed or winked by a unique resistance balanced solid state flash or wink generator.

Abstract: An interface unit for use between a telephone system in which a single-frequency tone is transmitted in both directions when the circuit is on-hook (idle) and a single-channel-per-carrier radio system in which the radio frequency carrier is not transmitted when the circuit is idle. A transmitting portion includes a single-frequency tone detector means responsive to termination or initiation of the tone from the telephone system to turn on the radio frequency carrier. A receiving portion includes a radio frequency carrier detector means operative to switch the telephone system from the output of a local single frequency local oscillator to a voice frequency line from the radio system, and a single frequency detection means to switch the telephone system back to the output of the local single frequency oscillator.

Abstract: The headset comprises a head-encircling band which has a rectangular cross-section, and it includes one or two earpieces which have housings with rectangular slots engaged over and slidable on each band end. In addition, a microphone arm having a microphone at one end and an opposite end with a rotatable ring portion engages through a bore of the ring portion onto the band holding the earpieces or onto a similar band formed on the end of the earpiece housing.

Abstract: An optically controlled bidirectional (bilateral) electrical switch is formed by a pair of photo-Darlington devices connected in series opposing (back-to-back) relationship between the two controlled terminals of the switch. Each of these photo-Darlington devices is shunted by a separate unidirectional diode element, such as a PN junction diode, arranged to conduct current only in the opposite direction from that of current flow through the corresponding shunted photo-Darlington device in its "on" condition. Four embodiments are shown.

Abstract: A private automatic branch exchange (PABX) system having first and second exchange units each including a marker and a switch frame wherein the connection between a central office called trunk belonging to the first exchange unit and a subscriber belonging to the first exchange unit is made through the switch frame of the first exchange unit by activating only the marker of the first exchange unit from a position circuit, and the connection between the central office called trunk and a subscriber belonging to the second exchange unit is made through the switch frame of the first exchange unit, an interunit trunk and the switch frame of the second exchange unit by sequentially activating the marker of the first exchange unit and the marker of the second exchange unit from the position circuit.

Abstract: A hand-held microphone assembly for use with two-way communications equipment in which an electret-capacitor microphone is mounted in the upper surface of the barrel portion of a pistol-shaped casing. A push-to-talk trigger disposed at the end of the barrel actuates a double-pole, double-throw slide switch to couple the output of a local preamplifier in the casing to an audio output line leading from the casing and to make suitable couplings between three changeover lines. A resilient conductive strip disposed within the casing at the inner end of the slider element is actuated in response to the operation of the double-pole switch to couple the preamplifier to a normally disconnected amplifier power supply in the casing.

Abstract: A headset for use in a voice communication system which provides a common audio signal, such as a radio receiver signal, to a plurality of such headsets. The headset includes an earphone having a double voice coil and an ambient sound microphone arranged to receive sounds from the surrounding environment. One of the voice coils is coupled to the common audio signal, while the other coil receives a signal from the ambient sound microphone to permit simultaneous monitoring of the two signals while preventing undesirable signal interaction.

Abstract: A two-path intercom system wherein a first link or path is non-exclusive and the second link or path is exclusive. When the system is idle, the first call is automatically switched to the second link or path when the called party answers. While the first conversation is taking place on an exclusive basis, a subsequent call will be switched to the first link or path, on a non-exclusive basis. The subsequent call is automatically switched to the exclusive second link or path when said second link or path becomes idle. The system includes a conference feature whereby tone dialing phones may switch up to three stations to the second link for a private conference. An intercom code not assigned to a station is used to set up the conference. A conference on the first link may be established when the second link is busy; when the second link becomes idle, the conference is automatically switched to the second link. In the idle state all stations are connected internally to the first link or path.

Abstract: A switch actuating device for a telephone instrument of the one piece type comprising actuating means protruding through the base portion of the instrument for actuating the off-on switch when the instrument is removed from or put on a table surface. Said projecting actuating means comprises along a peripheral outline of said base portion distributed parts, each of which cooperates with an element which actuates the contact springs of the switch. Said element is symmetrically constructed and comprises two links and two arms. The links are turnably mounted in bearings, are spring actuated and are at their ends actuated by the said actuating means.