Abstract: A precision rectifier circuit includes two differential amplifiers each having a negative feedback path including a diode. Two pnp transistors have their base-emitter paths connected in parallel with the respective diodes and their collectors connected together and via an output resistor to ground. An a.c. signal to be rectified is applied to non-inverting inputs of the amplifiers, whose inverting inputs are interconnected via a resistor in series with a capacitor, to develop a unipolar output voltage across the output resistor. The capacitor renders the output voltage independent of input offset voltages of the amplifiers. The transistors can comprise Darlington-connected transistors to avoid the need for matching.

Abstract: A gas filled surge arrester having improved impulse ratio, characterized by an ion source in an electric field outside of the spark gap.

Abstract: A telephone set base, for both wall and desk top mounting, has an elongate plastic molded base plate and a top housing. To improve stability a flat metal weight is positioned on the base plate and is spaced a small distance from the base plate to form an acoustic chamber. A speaker is mounted on the weight. A printed circuit board is mounted over the weight and modular jacks are attached to a flexible circuit member which connects to the printed circuit board, speaker, and other items. Recesses are formed in the base plate to provide for alternative arrangements of line cords and plug-in mounting on a wall. Slots in the base plate provide access to the recesses for cords entering at the ends of the base plate. A battery housing is provided.

Abstract: For a telephone handset, a rigid chassis is provided, of elongate form with positions at each end for mounting respectively a receiver and a transmitter and an intermediate position for a pushbutton dial. A flexible circuit member carries the majority of the various components for the handset. The flexible circuit is elongated and extends along the back of the chassis, down through a slot and back along the front of the chassis, with the pushbutton dial assembly attached to the flexible circuit member. The majority of the items such as electronic components, recall button, line cord jack and other components can be preassembled to the flexible circuit member which is then assembled to the chassis, followed by attachment of the pushbutton dial assembly.

Abstract: A modular telephone connector for use in providing connection of a telephone to both telephone lines and a separate power source, has a bottom member for fastening to a wall or other member at a required telephone position and a top assembly which attaches to the bottom member with a flat cable gripped between. On attachment of the top assembly to the bottom member, insulation piercing terminals pierce the cable and make contact with conductors in the cable. The top assembly includes a circuit board having conductor patterns to which the insulation piercing terminals are connected, and also to which are connected terminals from a modular jack, or jacks, mounted in the top assembly. A cover clips over top assembly and bottom member.

Abstract: An adaptable telephone baseplate can be used for either wall mounting or desk or table top mounting. The baseplate has an enclosed recess at an intermediate position and a modular jack position at what would be the top edge when wall mounted. A slot connects the jack position and enclosed recess. When wall mounted a short cord can be inserted in the slot with a plug at one end being inserted in the jack at the jack position and a plug at the other end being in the recess for insertion into a wall jack. When desk mounted a normal line cord enters through a groove into the jack position for insertion of a plug into a jack. Alternatively a line cord can enter through the groove, extend along the slot and then pass up through the slot for hard wiring of the conductors to a circuit board. Snap-in mountings are provided for the jack, a circuit board, ringer and possibly other items.

Abstract: A pushbutton dial assembly, particularly for a telephone handset, is in the form of a sandwich structure comprising a pushbutton member having a plurality of push buttons; a flexible transfer member having a plurality of actuating members, one for each push button, each actuating member having a domed portion extending away from the push button; a flexible contact member having a plurality of domed areas or bubbles, the domed areas extending towards the actuating members and in contact with the domed portions, the concave surface of each domed area having a conducting surface; a flexible insulating spacer member with apertures aligned with the domed areas; and a circuit member having a plurality of contact areas, a contact area aligned with each domed area, and a circuit pattern interconnecting the contact areas. Pressure on a pushbutton causes a domed portion to depress the related domed area which snaps through to make contact with the related contact area.

Abstract: A multiple cantilever spring contact switch has a plurality of cantilever spring contacts, in one or more series, with the contacts of each series clamped between surfaces which provided a predetermined relative inclination of the contacts. A pivotal member is mounted on the switch assembly for actuation by an operating member, the pivotal member in turn actuating the contacts. The contact between operating member and pivotal member is localized so that misalignment between operating member and the switch assembly does not affect actuation of the contacts. Such misalignment can occur when the switch assembly or operating member or both are mounted on printed circuit boards. The switch is particularly suitable for a hook switch of a telephone.

Abstract: The present invention provides a circuit for monitoring an a-c input signal to determine if the signal level falls within a selectable level range.

Abstract: Telephone signalling test apparatus is provided for monitoring telephone lines under live traffic conditions. The apparatus is modular with a main frame having a line interface and central control and storage unit, as well as numerical display.

Abstract: A communications line under test intercouples programmable local units, one of which transmits an analog waveform to the other in response to digital control signals received from a computer. The receiving programmable local unit transmits a digital signal to the computer representative of the received analog signal to thereby enable the computer to determine transmission characteristics of the communications line intercoupling the programmable local units.