Abstract: In a fluid level measurement system for the measurement of a level of fluid in a vessel the electrical impedance of a first conduction path between a central rod electrode and a surrounding cylindrical electrode and the electrical impedance of the second conduction path between the cylinder and the vessel are established. The first conduction path is restricted to be below the minimum fluid level by an insulating coating on the rod. The second conduction path varies with the fluid level. An output signal is extracted from the electrodes potentiometrically which is indicative of the fluid level. The signal may be linearized by application to a circuit having a matched non-linear transfer function. With this arrangement, a continuous output signal indicative of the fluid level is produced which is not subject to errors due to changes in fluid resistivity.

Abstract: A plurality of transmitters synchronized to a common clock each transmit a data signal spread by a common bipolar pseudo-random code having a different assigned code sequence shift. A receiver, synchronized to the clock, discriminates the signal transmitted by a predetermined transmitter from signals transmitted by the others by generating a first pseudo-random code that is a replica of the common bipolar pseudo-random code and has a code sequence shift corresponding to that of the predetermined transmitter, and a second bipolar pseudo-random code that is a replica of the common bipolar pseudo-random code and has an unassigned code sequence shift. The difference between the first and second bipolar pseudo-random code sequences, which is a trinary code sequence, is cross-correlated with the incoming signal. The cross-correlation despreads only the signal having the predetermined code sequence shift.

Abstract: A snap-fitting cover assembly for the terminal block (12) of an electrical transformer (10) comprises a backing plate (18) having apertures (20) for receiving terminals (14) of the transformer and adapted to be mounted against the terminal block (12). The width of the backing plate 18) is slightly greater than the width of the terminal block (12) so that opposite side portions (A) of the plate (18) extend beyond the block. A cover (28) adapted to fit over the backing plate (18) and block (12) has a pair of inwardly extending ears (26) that snap fit around the extending portions of the backing plate (18). With the backing plate (18) secured to the transformer terminals (14) by nuts (24), the cover (28) is retained to the terminal block (12) by a seal wire (34) extending through the cover (28) and behind the plate (18).

Abstract: The photosensitivity of a photomultiplier dynode to white light or infrared radiation is greatly reduced by coating the dynode with a layer of an alkali halide material having good secondary electron emission characteristics. A method of applying the coating to the dynode is also described.

Abstract: Pulses generated by the pulse initiator of an electricity meter (30) are counted during successive measurement intervals. The pulse count for each interval is stored in the solid state memory (42) of a recorder (10), to be thereafter transmitted to a central computer and printed and/or displayed to obtain energy demand survey and billing data. The operation of the recorder is controlled by a programmable microprocessor (38). To verify the accuracy of the pulses counted during each interval, the counts are accumulated over a predetermined number of successive intervals constituting a record. The accumulated count is compared with an encoded register reading obtained from the meter (30) at the end of the record. If there is acceptable correlation between the accumulated count and encoded meter reading, the interval pulse counts associated with that record are deemed verified.

Abstract: A digital signal processor (10) has a crossbar network (110) interconnecting a control and timing circuit (100), a multiplier (112), a serial access data memory (128), temporary storage registers (122, 124, 126), an accumulator (120) and input and output inferfaces (130, 132). Instructions in an external memory (12) are decoded by the control and timing circuit to cause the crossbar network to interconnect the other circuit elements in various patterns to feed selected signals from the input interface and stores to the multiplier, and the multiplier results to the stores and output interface. The sequence of interconnection patterns can be chosen to provide a selected signal processing function such as filtering. A multiplicand register (116) and a substitution circuit (118) enable the data to be modified in transit to implement other more complex signal processing functions.

Abstract: A single jet liquid meter comprises a cylindrical measuring chamber having first and second end walls perpendicular to the axis of the chamber, an injector and an ejector in communication with the measuring chamber, and a turbine having a hub and plurality of blades fixed to the hub. The hub has first and second end faces disposed opposite the first and second end walls, respectively. A pivot and shaft guide the turbine in rotation about the axis of the chamber. A set of radiating ribs are fixed to the first end wall and project into the chamber. The meter further includes an assembly consisting of an axial stop disposed adjacent the first end face and includes a pivot having a tapering point and an abutment which is in contact with the point when the liquid flow rate is zero. The meter is arranged such that the second end face is subjected to a pressure reduction effect produced by rotation of the liquid in the chamber.

Abstract: A magnetic circuit, such as used in a magnetic recording head, or with a Hall-effect device, is biased by applying signals having noise-like properties to the magnetic circuit. Since the biasing signals will be effectively uncorrelated with other signals being applied to the magnetic circuit, the biasing signals cannot introduce an offset in the applied signals which might otherwise cause distortion. In addition, the spectrum of the biasing signals is broadband and of low amplitude. As a result, the biasing signals are unlikely to cause interference with other nearby electrical components.

Abstract: Method and apparatus for determining, at a measurement point in a faulty conductor of electrical energy, a fault parameter such as the distance between the point of measurement and such fault or the direction of such fault. As a signal of a fault current, the device utilizes a signal I.sub.pa formed by a linear combination of a signal representative of homopolar current and a signal representative of an inverse current associated with a fault. The invention is particularly applicable in the case of networks having at the point of measurement an insensitivity to homopolar current or to inverse current.

Abstract: A method of manufacturing a memory card comprises taking an electronic module, which includes an insulating substrate and an integrated circuit, and locally raising the temperature of the plastic material of the card to its softening point. The module is then applied, with pressure, on one side of the card at its softened location to embed the module in the plastic material.

Abstract: Tape drive apparatus having a drive roller 1 and pinch roller 2 including a idler roller 3 around which tape 4 passes. The pinch roller 2 which is rotatable about two normal axes (A2 and A4), is resiliently urged against the drive roller 1 and the idler roller 3, the two rollers being spaced apart from each other. This apparatus is particularly useful for magnetic tape cassettes, the pinch roller 2 being formed as either part of the cassette or as part of a tape recorder/player for using a cassette.

Abstract: A frequency and phase demodulating circuit provides direct frequency demodulation utilizing only addition, subtraction and multiplication steps. Division of signals is avoided, as is the need for a look-up table of trigonometric values corresponding to the results of such division. By maintaining a substantially constant input amplitude to a quadrature sampler, a number of approximations may be made without introduction of error. Compensation for actual signal variation, as well as for first order errors due to the approximation process of the invention, results in accurate frequency evaluation and avoids the necessity for differentiating an initial phase determination.

Abstract: To energize an electromagnetic clutch or other electromagnetic device having a movable armature, a voltage is applied across the coil of the device to cause an initial current to flow therethrough. A current dip upon initial movement of the armature is detected, and in response, a substantially linearly increasing current is applied to the coil, establishing a controlled movement of the armature.

Abstract: A battery backup circuit for a CMOS RAM is isolated from the negative, or ground, power supply rail of the memory so that the memory is held at a potential which is sufficiently different from that of the normal write-enable signal (usually zero volts) to prevent spurious signals from affecting the memory.

Abstract: A plurality of transmitters synchronized to a common clock each transmit a data signal spread by a common bipolar pseudo-random code having a different predetermined assigned code sequence shift. A receiver, synchronized to the clock, discriminates the signal transmitted by a predetermined transmitter from signals transmitted by the others by generating a first bipolar pseudo-random code that is a replica of the common bipolar pseudo-radom code and has a code sequence shift corresponding to that of the predetermined transmitter, and a second bipolar pseudo-random code and has an unassigned code sequence shift. The difference between the first and second bipolar pseudo-random code sequences, which is a trinary code sequence, is cross-correlated with the incoming signals. The cross-correlation despreads only the signal applied by the sequence having the predetermined code sequence shift.

Abstract: A fluid pressure transmitting diaphragm assembly is disclosed in which a diaphragm support plate (14) and a force transmitting disk (16) are attached respectively to the outer flange (46) and inner flange (48) of an annular diaphragm (44) having a concave portion (50) between the flanges, the concave portion having been formed by fluid pressure acting on the diaphragm to freely deform it following hermetic welding of the flanges. A method of manufacturing such an assembly also is disclosed.

Abstract: A plurality of single-phase energy sensors each having a first input connected to a current converter and a second input connected to voltage converter supply pulses to a calculating device. The number of pulses over time represents the energy detected by the single-phase sensor. The calculating device is based on a microprocessor and comprises accumulators controlled by the pulses delivered by the energy sensors for supplying the active and reactive power measurements sought. In the case of a four-wire network, it is not necessary to use voltage transformers for the interphase network voltages, and the energy sensors supply pulses which represent the active and reactive energy of each phase.

Abstract: A digital "signature plug" for applying digital signals representative of shaft characteristics to a digital shaft torque measuring system comprises a printed circuit mounted on an insulating support. The support has an input pin connected to a common printed circuit track, which is connected in turn to sixteen output pins via respective individual printed circuit tracks. The support is shaped beneath each of the sixteen individual tracks to facilitate severing of the track with a punch tool, so that any desired combination of the output pins can be disconnected from the input pin. Consequently, if a logic level 1 signal, for example, is applied to the input pin, any desired pair of eight-bit digital signals can be produced at the output pins.