Abstract: An audio current pick-up device for use with an electric wire 6 carrying an electric current containing audio information comprises a pair of substantially identical magnetic induction coil assemblies 26, 27 disposed in parallel to each other with an axial deviation and orthogonally to the wire, each coil means including a magnetic core in the form of rod 30, 38 and a pair of induction coils 32A, 32B, 39A, 39B wound in opposite directions on respective halves of its core rod. An output of either of the induction coils is phase-shifted by a preset amount and composited with an output of the other magnetic induction coil to form a sound pick-up signal from which a sound output signal is derived.

Abstract: A transmission control unit disclosed is used when an electronic device which is usually directly connected to a telephone line is used via a public telephone or the like. In this case, the transmission control unit is connected to a MODEM included in the electronic device, and a microphone and a speaker of the transmission control unit are brought to confront the speaker and the microphone of the telephone. When the transmission to the electronic device on the other end of the line is conducted, tone dialing is conducted to make a call and data is then transmitted. The thus transmitted data is converted by a converter of the transmission control unit so as to be transmitted to the telephone line connected to the other end of the line, while data from the electronic device on the other end of the line is transmitted and converted so as to be supplied to the MODEM.

Abstract: A coupler for a balanced two wire data transmission line includes input and output ports as well as a forward coupled port and a reflected coupled port. The coupler is constructed of passive components including transformers and resistors to provide at the forward coupled port a signal proportional to the signal transmitted from a source to a load and provide at the reflected coupled port a signal proportional to the magnitude of the signal reflected from the load due to mismatch.

Abstract: A portable device to be carried by a reporter and coupled to a telephone line to a location from which the reporter wishes to transmit a report to a broadcast station to be broadcast live has a casing with a microphone (1) for voice input, a tape input (2) for receiving a tape signal and a monitor (3) for providing acoustic signal to the reporter.The device has signal conditioning circuitry including voice control gain adjustment (20) and amplification (5) for providing a signal to be transmitted by the telephone line in a form suitable for broadcasting. The device is coupled to the telephone line by a hybrid transformer arrangement (7 to 14) which serves to cancel unwanted components of the signal to be sent down a telephone line from that to be received from the telephone line. The device is portable and has its own power supply in the form of batteries or connections for an AC mains auto supply.

Abstract: The present invention provides an insert (1) forming an independent assembly of a coil body (15). The electroacoustic transducer comprises an insert (1) formed of a case with a vibrating membrane (2) and its electric connectors (4, 5) and a coil body (15) distinct and separable from the insert. The coil body can be fitted to the rear face (14) of the insert and comprises axial passages (20, 21) through which the insert connectors (4, 5) pass. Contact pieces (22, 23) provide the electric connection of the coil with the insert connectors.

Abstract: An optical hookswitch assembly useable on a telephone set as an optical communications port is disclosed. The hookswitch assembly is comprised of light emitting and detecting diodes so disposed in the telephone so as to detect the presence of a handset. A processor connectable to the telephone circuitry and the light emitting and detecting diodes is provided such that the telephone circuitry is activated by the processor when the light emitting and detecting diodes fail to detect the presence of a handset. The light emitting and detecting diodes are useable as an optical communciations port for accessing the processor by allowing an external computer to communicate with the processor via an optical coupler.

Abstract: The automobile telephone is used in a hands-free condition by coupling its handset with a cradle-shaped coupler which is provided with a pair of swingable support plates for receiving a transmitter portion and a receiver portion of the handset in use to make it possible to receive the handset regardless its size and mounting angle. On a back surface of the swingable support plates are provided a speaker and a microphone which are coupled with the transmitter portion and the receiver portion of the handset respectively so as to make it possible to use the telephone in a hands-free condition through these speaker and microphone incorporated in the cradle-shaped coupler.

Abstract: At a transmission line (La', Lb') connected with telephone station equipment (Tel) via a lowpass filter (TP), via which telephone station signals are transmitted in a first frequency range, there is connected via a line transformer (U3) a data terminal (DG) which is able to receive and to send data signals in a second frequency range above the first frequency range. On its side toward the transmission line (La', Lb'), the lowpass filter (TP) has a capacitive termination (C7) which is rated so that its a-c resistance is in the order of magnitude of or preferably less than the characteristic impedance of the data transmission line in the second frequency range.

Abstract: Apparatus (10) for providing isolation and interconnection between the tip (1) and ring (2) conductors of a telephone line and data communications equipment to be connected thereto, such as a modem or other device (12). The apparatus serves also as a circuit for dialing the telephone, responsive to dialing signals applied thereto. All switching is done electronically, eliminating the need for mechanical relays. A diode bridge (18) is connected to the tip (1) and ring (2) conductors of the telephone line; the active circuitry of the interface derives power through the bridge. A switchable constant-current load (48, 20, 22) is placed across the output nodes of the bridge. The load is switched by an opto-isolator (40) which, in turn, is controlled by the line-seizing switch of the data communications equipment. When the line-seizing switch is closed (i.e., the device is off-hook), the opto-isolator (40) causes the switchable load to place a low impedance d.c.

Abstract: A telephone handset having a receiver housing at one end has a flux coil positioned at the front corner at the junction between the peripheral wall and the front wall of the housing. The flux coil is connected in series or in parallel with the receiver. The flux coil, by this arrangement, is positioned very close to the front face of the receiver housing, giving very good coupling between flux coil and a hearing aid. Normally unused space is occupied by the flux coil and permits use of any convenient receiver.