Abstract: A single-port RAM generator architecture, for the generation of different RAM structures in a CAD environment, and to test the operation capabilities of the different RAM structure. The architecture includes a Static RAM matrix and a self timed architecture, which includes a control logic, both a dummy row and a dummy column having respectively equivalent load of a word line and of bit column of said matrix. The dummy column is discharged at a faster rate than the corresponding bit column optimizing the timing and reducing power consumption. Different column multiplexer selections provide different RAMs for a selected RAM size, each having slightly different silicon area and timing performance.

Abstract: A circuit protects a power transistor of the vertical MOS or IGTB-type during the off state against forward overvoltages. The protection circuit includes a first circuit for limiting the voltage across the transistor to a predetermined voltage, lower than the forward breakdown voltage of the power transistor, a circuit for detecting the quantity of energy dissipated in the transistor when the first circuit is enabled, and a second circuit for turning the transistor on at low impedance. The second circuit is enabled when the detection circuit has detected that the dissipated energy has exceeded a predetermined energy threshold.

Abstract: A programmable frequency sine wave signal generator, including a generator for generating square-wave signals having a programmable frequency; a counter for counting the periods of the square-wave signals; circuits for providing successive discrete sine wave values from successive states of the counter; and a low-pass filter receiving the successive discrete sine wave values and providing the sine wave. The low-pass filter is a switched-capacitor filter with a switching mode that is controlled by a signal having a frequency proportional to the frequency of the square-wave signal. Correct selection of the values of the filter capacitors allows the cut-off frequency of the filter to be continuously substantially the same as the frequency of the sine wave.

Abstract: A self-priming centrifugal pump includes a cylindrical metal plate case forming a pressure chamber and provided with a suction inlet and a pressure outlet. The pressure chamber has a bladed impeller with a peripherally arranged diffuser, an axial ejector device including a venturi tube, and a torus-shaped interspace adapted to convey the emitted flow from the radial diffuser towards the pressure chamber. A single curved blade is arranged in the lower portion of the interspace and extends from the peripheral region of the radial diffuser up to a central annular outlet passage of the interspace which extends all around said ejector device in such a manner to counteract the rotational component of the fluid speed direction and to promote separation of air.

Abstract: A method and apparatus for reducing the acoustic noise of an electromechanical load. Switching frequencies are chosen so that the switching ripple is submerged in the natural noise of the load. This device includes a converter which, through use of one or more pulse switches, controls the load, a chopper circuit and a control unit, a random number generator being linked to the chopper.

Abstract: A phase/frequency comparator includes: two inputs which respectively receive first and second logic signals; a first logic gate which is at an active state during a duration equal to the phase advance of the first signal with respect to the second signal; and a second logic gate which is at an active state during a duration equal to the phase advance of said second signal with respect to the first signal. The phase/frequency comparator also includes: a first switching element operated by the active state of the second gate to prevent transmission to the first gate a state liable to switch the first gate to its active state; and a second switching element operated by the active state of the first gate to prevent transmission to the second gate a state liable to switch the second gate to its active state.

Abstract: Bipolar transistors and MOS transistors on a single semiconductor substrate involves depositing a single layer of polysilicon on a substrate, including complementary transistors of either or both types, and a method for fabricating same. The devices are made by depositing a single layer of polysilicon on a substrate and etching narrow slots in the form of rings around every bipolar emitter area, which slots are thereafter filled with an insulating oxide. Then, emitters and extrinsic base regions are formed. The emitters are self-aligned to the extrinsic base regions. An optional cladding procedure produces a surface layer of a silicide compound, a low resistance conductor. The resulting structure yields a high-performance device in which the size constraints are at a minimum and contact regions may be made at the top surface of the device.

Abstract: A double beam cyclotron maser comprising two electron guns for introducing two electron beams traveling parallel to each other at different speeds into an electron drift tube/waveguide. The beams have respectively different electron cyclotron space-charge harmonics. A solenoid maintains a magnetic field parallel to the direction of propagation of the electron beams while a magnetic wiggler field initially imparts a transverse force to the electrons such that they propagate down the drift tube with a helical gyration. The magnetic fields, electron beam velocities, and beam space charge harmonics are adjustable to set the interaction frequency at which amplification of electromagnetic radiation can occur. The waveguide is a slow wave structure so configured as to slow the signal from the magnetron to match the phase velocity of the double stream cyclotron space-charge wave.

Abstract: A retainer for holding a printed circuit card in a card rack or the like is disclosed. The retainer comprises a plurality of wedge-shaped members slideably mounted end-to-end on a rod, with at least one of those members being moveable in a transverse direction relative to the rod and to its respective adjacent members upon effective shortening of the rod to thereby bring a clamping surface of the transversely moveable member into contact with a printed circuit board and to apply a clamping force thereto. The rod is formed of an alkaline metal alloy that has been tempered to provide the rod with sufficient strength and decreased weight.

Abstract: A semiconductor laser gain structure having a tapered gain region comprising cavity spoilers for receiving light which is reflected off of the output facet back into the semiconductor and removing it from the gain region so as to reduce or eliminate self oscillation. The boundaries of the gain region are also designed to have a very low refractive index gradient so as to minimize reflection of light off of the boundaries back into the gain region. The gain structure may be embodied in a semiconductor laser oscillator or semiconductor laser amplifier depending on whether the input facet is or is not, respectively, anti reflection coated. The output facet is anti-reflection coated in either embodiment.

Abstract: Improved electrolytic cells for producing metals by the electrolytic reduction of a compound dissolved in a molten electrolyte are disclosed. In the improved cells, at least one electrode includes a protective layer comprising an oxide of the cell product metal formed upon an alloy of the cell product metal and a more noble metal.In the case of an aluminum reduction cell, the electrode can comprise an alloy of aluminum with copper, nickel, iron, or combinations thereof, upon which is formed an aluminum oxide protective layer.

Abstract: Calendering takes place in a calendering zone which operates under pressure with application of temperature and moisture. The desired smoothness is achieved with a correspondingly long dwell time of the material web in a correspondingly long calendering zone in view of the speed of web travel. A web which is still wet is guided between parallel heatable surfaces which are arranged on both sides of the web and face each other through the web and can each be pressed against the web. The surfaces are designed to form and hold a given precise contour of the calendering zone over its full length. One surface is constructed e.g. as a casing of a heated roller and the second surface is constructed as an endless flexible belt which can be pressed in a direction towards the roller casing by means of a concave supporting element. If wished, the web can be calendered on both sides with the method.

Abstract: An adaptor for interconnecting two or more IEEE-488 cables, each cable terminating in a connector having a male fitting. The adaptor includes a housing defining first and second ports which are disposed on opposite sides of the housing, and a pair of first and second electrically connected female fittings. The first female fitting is disposed in the first port and the second female fitting is disposed in the second port to enable the two IEEE-488 cables to be interconnected using the male fittings while leaving exposed their corresponding female fittings.

Abstract: A method and apparatus for encoding data to be transmitted through a RS-422 standard serial interface such that the encoded data approximates one of the Control-L, Control-S wired or Control-S infrared protocols used in some audio and video equipment. Each bit of a data byte to be transmitted to the audio/video equipment is converted into one or more expansion bytes and transmitted at a baud rate such that the encoded bits approximate the shape and size of a bit in the data format of the selected protocol. In the case of Control-L protocol, the receiving port of the RS-422 is coupled directly to the serial interface port of the controlled device while the transmitting port is coupled through a diode to the serial interface port of the controlled device. For Control-S wired protocol, the transmit port of the RS-422 is coupled by an uninterrupted wire to the serial interface port of the controlled device.