Showing papers by "Motorola published in 1981"

Fault detection and diagnostic system for automotive battery charging systems.

Abstract: An in situ self-diagnostic automotive alternator battery charging system is disclosed. Included are: a battery; voltage regulator sensing battery voltage and generating an excitation signal; and an alternator driven by a vehicle engine provide a rectified electrical signal to charge the battery in response to the excitation signal. Electronic circuit status detectors, variously coupled to the battery, voltage regulator and alternator, maintain a first logic state when a corresponding signal characteristic is within a predetermined range and a second logic state when the corresponding characteristic is outside the predetermined range. Combinatorial logic means respond to a logic state sequence from the detectors to identify predetermined sequences of the logic states resulting in the identification of faults in the charging system. The logic means also provides a warning to the operator of detection of a fault and a display of the location of the fault as occurring in one of the major components of the charging system.

Ripple detector for automotive alternator battery charging systems

Abstract: Detector (28) monitoring the voltage ripple in the rectified electrical output signal of an alternator (22) in a multiphase alternator battery charging system. A circuit monitors the undulating alternator output signal and produces a signal level in response. To correct the detector operation for various magnetic phenomena present in the alternator, a first circuit measures the rotational speed of the rotor and produces a proportional signal. A second circuit determines the excitation current supplied to the field coil. The measurement and determination are separately weighted and combined to form a corrected comparison threshold value. A variable threshold circuit combines the signal proportional to the rotational speed of the rotor and the determined field coil excitation current to produce a combined signal level. Comparison means compare the signal level from the monitored alternator output signal with the combined signal level and produce an output signal level indicative of the detection of a voltage ripple in excess of the combined signal level. The output signal is corrected for the effects of significant alternator performance characteristics.

Method of mounting interrelated components.

Abstract: One specially designed fixture allows two components such as a microprocessor and its associated ROM to be simultaneously mounted on opposite surfaces of the substrate, with all or nearly all internal connections made through the area of the substrate between the components. A second fixture allows for wave soldering lead frames to the assembly while protecting the reflow soldered components. The method thus provides the most direct connections between the two components with all internal connections and external connections made by two automatic operations. A third component can be positioned astraddle the mounted assembly for minimum lead lengths.

Silicon pressure sensor

Abstract: A monolithic silicon pressure sensor employing a four-terminal resistive element is formed in a thin monocrystalline silicon diaphragm. The resistive element is a diffused resistor having current contacts at the ends and two voltage contacts located midway between the current contacts and on opposite sides of a current axis defined between the two current contacts. The thin silicon diaphraghm has a square shape and is oriented in a (100) silicon surface with its sides parallel to a [110] crystal orientation. The resistor is oriented with its current axis parallel to a [100] crystalline direction and at 45 degrees with respect to the edge of the diaphragm to maximize sensitivity of the resistor to shear stresses generated by flexure of the diaphragm resulting from pressure differentials across the diaphragm. With a current flowing between current contacts, a shear stress acting on the resistor generates a voltage which appears at the voltage contacts and which is proportional to the magnitude of the shear stress.

Polling system for multiple terminal units

Abstract: A semi-duplex communication system provides high channel efficiency by having the base station transmit a reference signal which each terminal uses as a sync signal. Each unit having data to send to the base responds with a very brief signal such as a burst of silent carrier transmission during an assigned time slot in a queue of slots. Only those units which responded thus are polled during the subsequent polling cycle. During the transmission time slots, the base can be sending acknowledgments to those terminal units having sent messages during the previous polling cycle. While polling for data or acknowledgments or sending acknowledgments, the base can also be listening for the respective responses. The address code of a terminal unit is further encoded to carry other required information in both directions.

Microstrip to waveguide transition

Abstract: A microstrip to waveguide transition is achieved by passing a portion of a microstrip circuit through an aperture in a transverse wall of a waveguide. The aperture is dimensioned and positioned so as not to significantly disturb propagation in the waveguide. A tab of the microstrip substrate extends through the aperture and into the waveguide, where a probe disposed on the tab couples to energy in the waveguide. The probe is connected to the microstrip circuit by means of a transition section on the tab within the aperture. The transition section is as narrow as possible to minimize capacitive coupling to the waveguide wall and is an integral multiple of one-half wavelength for a smooth impedance match from the probe to the microstrip.

Ttl to cmos input buffer

Abstract: A TTL to CMOS input buffer accomplishes buffering a TTL signal to a CMOS signal without static current flow when the TTL is a logic "1" by isolating the input from an input P channel transistor and using feedback from an input N channel transistor to turn off the P channel transistor. A second P channel transistor is used to couple a positive power supply voltage to the input P channel transistor in response to an output from the N channel transistor.

Memory management unit

Abstract: A memory management unit of use in a memory management system. The memory management unit selectively maps a logical address to a respective physical address in accordance with a selected one of a plurality of segment descriptors, each of which defines a logical-to-physical address mapping and a range of address spaces for which such mapping is valid. The mapping is achieved using an improved associative memory circuit. Means are provided to detect mapping conflicts between new segment descriptors and segment descriptors already stored, and to prevent the storage of such conflicting segment descriptors. A method and circuit are provided to coordinate the parallel operation of a plurality of the memory management units or the like.

Battery-saving arrangement for pagers

Abstract: A pager or other selectively-addressed electronic device powered by a small power cell operates in four different modes and at two power levels, depending on signals received and a timing sequence. The device can stay active continuously, be activated at intervals or remain in a powered-down state. The address code assigned to a particular device would be transmitted at a predetermined time interval following a sync signal, thus the device can be powered-down until the approximate time period in which its address code could be transmitted. The system provides increased channel efficiency since information codes are superimposed on actual address codes, and there is no dead time in a channel while there are address codes waiting to be transmitted. The system is particularly well adapted to time multiplexing.

Programmable digital data terminal for mobile radio transceivers

Abstract: In a data transmission system, for communicating messages between a base station and a plurality of mobile stations, each mobile station includes a radio frequency transceiver and a programmable data terminal for sending and receiving predeterminedly formatted digitally encoded messages. A keyboard subsystem and character display subsystem are controlled by a programmable microprocessor subsystem which also processes received and transmitted messages. A transmit and receive system clock interrupts the operation of the microcomputer to process messages. The messages include a cyclical redundant check byte as well as a control number byte. Characters which are not editable blink. A terminal status display line is provided and a message received character is also provided. The system sets the system clock period to be the same for all data rates. Automatic restart of the system is provided as well as a means for detecting and generating a pseudo-random message preamble. Cursor positioning, memory interchange, and display keys are provided. Receipt and acknowledgement of various types of messages are also provided.

Implementation of a tunable transmission zero on transmission line filters

Abstract: The invention is directed to a interdigital filter comprising a plurality of conductive strips positioned in a row and electromagetically coupled to one another. A conductive transmission line is positioned with respect to the row of conductive strips such that the two ends of the transmission line are capacitively coupled to the ungrounded ends of two nonadjacent conductive strips. This arrangement gives the frequency response of the filter a transmission zero. The frequency of the transmission zero can be adjusted by trimming the ends of the conductive transmission line so as to effect the capacitive coupling between the non-adjacent strips.

Sample and hold circuit

Abstract: A sample and hold circuit for producing an output voltage the magnitude of which is representative of the peak magnitude of a sampled input signal. The sample and hold circuit comprises a unity gain amplifier having an input terminal to receive said input signal and a cascoded output section for sourcing current at an output terminal. A discharge circuit is provided which includes a cascoded section for sinking current at said output terminal. Each of said cascoded sections being coupled to a capacitive load for charging or discharging the capacitor respectively to provide said output voltage.

Whip antenna construction

Abstract: A whip antenna assembly of conductive cable, conductive base section, conductive protection knob and a environmental cover. The conductive antenna cable is constructed of multiple layers of brass plated stainless steel wire wound in a helix about a single wire strand which serves as a central core. The conductive base section and conductive protection knob consist of a zinc alloy and are injection cast onto opposite ends of the conductive antenna cable. An environmental cover made from polyurethane is injection molded over the subassembly of conductive antenna cable, conductive base section and conductive protection knob.

Housing arrangement with breakaway battery access door

Abstract: An improved housing arrangement is disclosed for a small, hand-held battery powered portable device which includes an associated battery compartment with integral battery door accessible from the side of the housing. The battery door and compartment are intercoupled by a non-destructive, breakaway hinge device which permits separation therebetween when the door is pivoted outwardly from the top beyond a set predetermined limit. It may be reattached simply and conveniently by a press fit. A latch mechanism is included integral with the surface of the battery door which may be operated by hand without special tools to latch and unlatch the door.

Multiaddress pager with a call storage and priority paging option

Abstract: A pager includes means for receiving emergency calls immediately upon reception of the emergency calls and means for receiving non-emergency calls and, storing the non-emergency calls for subsequent readout upon interrogation. The pager is shown implemented in hard-wired logic form and alternatively in a programmable microprocessor form.

Scrambler key code synchronizer

Abstract: A method for synchronizing the scrambling sequences of communicating scrambler units of a privacy communications system in a reliable and secure manner. The method is particularly adapted for use in noisy or fade prone transmission environments, and permits late entry of authorized third parties to the system. The method utilizes digital sequences interleaved periodically with scrambled analog information to provide reliable synchronization.

Self-clocking data transmission system.

Abstract: Systeme de transmission de donnees ou des signaux de donnees sont transmis par le transmetteur (101 et Fig. 2) avec quatre etats binaires possibles a deux bits des lignes de signaux des donnees verifiees (221) et des donnees complementaires (220). data transmission system or data signals are transmitted by the transmitter (101 and Fig. 2) with four possible binary states two bits verified data signal lines (221) and complementary data (220). Un etat de texte est prevu avant et apres le signal de donnees et un etat un ou un etant zero suivi d'un etat de bit est prevu pour chaque bit du signal de donnees. A text is expected state before and after the data signal and a state one or a zero being followed by a bit of state is expected for each bit of data signal. Les recepteurs de donnees (102, 103, 104, et Fig. 3) detectent l'etat de bit pour recuperer un signal d'horloge binaire (311) et detecter l'etat un et l'etat zero pour recuperer un signal de donnee NRZ (305, 306). The data receivers (102, 103, 104, and Fig. 3) detect the bit state to recover a bit clock signal (311) and detect the state and a zero state to retrieve a given signal NRZ (305, 306). En reponse au signal d'horloge de bit, le signal de donnees NRZ est introduit par decalage seriel dans un registre (312) tandis qu'un signal de donnees de retour charge anterieurement en parallele est sorti par decalage du registre (312) et est applique (314, 315, 316) a la ligne de signaux de donnees de retour. In response to the bit clock signal, the NRZ data signal is introduced by seriel lag in a register (312) while a return data signal in parallel load previously walked out of lag register (312) and is light (314, 315, 316) to the return line of data signals.

Phase corrected clock signal recovery circuit

Abstract: As shown in Fig. 4 a phase corrected clock signal recovery circuit (150) for multilevel digital signals includes a transition marker generator (200) for generating a narrow width pulse each time a received multilevel digital signal crosses one of the threshold levels between the adjacent logic levels of multilevel signal. Picket fence-like pulse trains are thus formed, the pulses (transition markers) of which correspond to the threshold crossings of the received digital signal. The pulse trains are interspersed with spaces or eye intervals which correspond to the absence of any threshold crossings. Each eye interval additionally corresponds to the time during which each respective bit of digital signal information is transmitted. The rate of occurrence of the pulse trains is substantially equal to the clock frequency of the received digital signal. A phase error detection circuit (400) is operatively coupled to the output of the transition marker generator (200) and to an electronically tune bandpass filter (300) capable of adjusting the phase of the pulse trains. More specifically, the phase error detection circuit (400) includes an up/down counter (410, 411) and adjusts the phase of the clock signal recovered from the pulse trains such that the number of transition markers generated during the high portion of the clock signal equals the number of transition markers generated during the low portion of the clock signal. Thus, selected transitory edges of the pulses of the recovered clock signal are centered at the middles of the respective eye intervals, that is, at the points in time when each respective bit of multilevel digital signal information occurs. This phase corrected recovered clock signal is conveniently applied to appropriate sampling circuitry to enable sampling of the multilevel digital signal at optimum times, that is, at the center of the eye intervals.

Dual mode dc/dc converter.

Abstract: A DC/DC converter operates at peak efficiency in either of two output current level states in response to the power demands of an associated electronic device, thereby reducing wasted current to a minimum. The converter is designed to operate from a one-cell battery, and is particularly suited to an integrated circuit implementation.

Dopant predeposition from high pressure plasma source

Abstract: A method is provided for predepositing dopant material on semiconductor substrates. The semiconductor substrates are positioned within a high pressure plasma reactor apparatus. A high pressure rf plasma is generated in the apparatus at a pressure of about one atmosphere or greater. Dopant materials such as B2 H6, PH3, or AsH3 are introduced to the plasma and form ionized species of the dopant. The plasma and the ionized species are directed to the surface of the semiconductor substrates whereon a uniform layer of the dopant is deposited.

Faultindicating circuit for an automotive alternator battery charging system

Abstract: A fault indicating circuit (17) for an automobile alternator battery charging system. The charging system comprises an alternator (11) providing a rectified battery charging signal in response to alternator field coil excitation which is controlled by a voltage regulator (15) that senses battery voltage. The fault indicating circuit comprises a low voltage detector circuit (58) which provides constant DC excitation for an indicator lamp (19) in response to low alternator output voltage and a high voltage detector circuit (57) which provides intermittent excitation for the lamp in response to an excessively high alternator output voltage, the lamp (19) being maintained in a de-energized state in response to the normal alternator output voltage.

Method and apparatus for automatically attempting to seize a radio channel in a multichannel communication system

Abstract: Apparatus is disclosed for enabling a mobile radiotelephone to automatically attempt to seize a radio channel in a multichannel radio communication system. The mobile radiotelephone scans the radio channels for a non-busy radio channel and provides an indication signal when detecting a non-busy radio channel. A counter which is continuously clocked by a clock signal is incremented for each clock cycle interval of the clock signal in response to the presence of the indication signal and is decremented for each clock cycle interval of the clock signal in response to the absence of the indication signal. Thus, the totalized count of the counter is proportional to the degree of radio channel blocking of the radiotelephone system. After an unsuccessful channel seizure attempt by the mobile radiotelephone user, time interval generating circuitry provides a random time interval that has a maximum magnitude that is inversely proportional to the totallized count of the counter. Thus, the maximum random time interval is shortest when the totallized count of the counter is greatest. At the end of the random time interval, circuitry automatically attempts to seize a radio channel and if unsuccessful, additional automatic channel seizure attempts are provided after corresponding random time intervals. Thus, overall radiotelephone system efficiency is enhanced by dynamically optimizing the average random time interval between automatic channel seizure attempts according to the degree of radio channel blocking.

Bonding means and method

Abstract: A new wire bonding capillary design is employed in which the bonding and cutting surfaces of the bonding capillary are separated. The bonding capillary tip has an annular bonding surface and an annular cutting ridge raised from the bonding surface and of smaller diameter.

Plasma pressure pulse sterilization.

Abstract: A sterilization procedure and apparatus is disclosed in which articles of irregular shape or having long, narrow apertures or cavities may be sterilized at low temperature by being subjected to a plasma whose pressure is varied in a cyclic manner so as to provide forced convection of active species into the apertures, cavities, and crevices of the article to be sterilized

Non-hermetically sealed stackable chip carrier package

Abstract: An improved stackable integrated chip carrierassembly is disclosed which is especially suited for use in printed circuit board with dense configuration of components in limited areas of surface. The chip carrier assembly is mounted on an associated circuit board and allows the vertical stacking of active components in chip form, integral therein. The interconnections of the associated integrated circuit chips are accomplished without soldering which lends itself for easy disassembly when it becomes necessary to remove or replace an internal chip. The chip carrier assembly has an adaptable design allowing single or vertically stacked utilization of the module-like package. To achieve the necessary electrical isolation property, a ceramic cap is placed at the upper most position relative to the integrated module assembled package. This design has relatively few parts and allows smaller diameter wire to be used to achieve the required integrated circuit chip to package electrical bonding connections, when such is required.

Thermal Characteristics of 16- and 40-Pin Plastic DIP's

Abstract: The thermal performance of 16- and 40-pin plastic dual in-line packages (DIP's) is described in light of current trends towards higher device powers and ambient temperatures. Extensive experimental and computer modeling studies on both package types have revealed that extraordinary improvements in thermal characteristics can result from proper selection of package materials and cooling parameters. In particular, judicious choices of leadframe material, molding compound, heatspreader, and mode of external cooling can lead to excellent thermal performance. To accomplish this, component manufacturers and system users must work closely to properly select materials and conditions to maximize effectiveness. In the best case, thermal resistances of 38°C/W and 26°C/W were found for 16- and 40-pin plastic DIP's using forced air cooling. The importance of both device power level and board temperature rise above ambient on theta JA is discussed in some detail. Suggestions are made to both component manufacturers and system users on how to minimize variations in measured theta JA .

Low cost electro-optical connector

Abstract: A low cost electro-optical device is disclosed in which a plastic encapsulated, electro-optical semiconductor device is provided with an aperture into which a segment of optical fiber can be inserted. A suitable connector member is also described.

Power amplifier and envelope correction circuitry

Abstract: Generating apparatus providing a preferred pulse envelope which is compared to the envelope of output pulses from a nonlinear power amplifier, the error between the two being used, along with a stored predistorted pulse, to generate an updated predistorted pulse that is utilized to modulate the input signal to the nonlinear amplifier to produce a pulse at the output thereof having the preferred envelope and to update the stored predistorted pulse.

Bonding method adaptable for manufacturing capacitive pressure sensing elements

Abstract: A method of utilizing anodic bonding to bond a conductive semiconductor wafer to a metallized dielectric glass plate so as to form a capacitive pressure sensing element is disclosed. The method includes positioning the semiconductor wafer in contact with the glass plate, heating the wafer and glass plate and applying a substantial positive DC potential to the semiconductor wafer and metallization on the glass plate while applying a negative DC voltage potential to the glass plate. The glass plate metallization forms one capacitor plate of the capacitive pressure sensing element while the semiconductor wafer forms the other capacitor plate. By applying the same voltage potential to the glass plate metallization and the semiconductor wafer during anodic bonding of the wafer to the glass plate, the corona field between the glass plate metallization and the semiconductor wafer is reduced thereby improving the bond between the wafer and the glass plate and reducing the possibility of arcing between the semiconductor wafer and the glass plate metallization. Also sodium ion migration to the glass plate metallization and any metallization connected to this metallization is inhibited wherein the ion migration would impair the subsequent solderability of these metallizations.

Moisture and dust seal arrangement for a portable radio or the like

Abstract: An improved moisture and dust seal assembly is disclosed which is especially suited for application in small hand-held radio apparatus or the like which includes a molded plastic enclosure. A vertical wall is provided on one of the mating members forming the enclosure, such as the cover. The wall has essentially right angle corners and is adapted to receive a standard O-ring thereabout. The assembly is completed by affixing a ribbon-like member, in the form of a closed loop, to the top of the verticle wall. The ribbon-like member extends a predetermined distance beyond the edge of the verticle wall to form a groove-like space for retaining the O-ring. The ribbon-like member may be affixed to the top of the wall by a convenient heat staking operation.