Abstract: The undesired temperature variation of a capacitive pressure sensing element (10) having a positive temperature coefficient of capacitance (TCC) is compensated by a series resistor R and compensating capacitor (C.sub.c) connected in parallel to the pressure sensing capacitor (C.sub.x). The compensating capacitor and presssure sensing element have opposite polarity temperature coefficients of capacitance, and the magnitude of the resistor is selected such that its resistive impedance is nonnegligible and is comparable to the magnitude of the capacitive reactance of the pressure sensing capacitor or compensating capacitor at a predetermined operative frequency of an electrical signal applied to and/or determined by the pressure sensing and compensating capacitors.

Abstract: An electrical component assembly (10), comprising a rectifier bridge, utilizes a protective cover (30) for mechanical protection of semiconductor diode dies (11, 12) mounted on an aluminum heat sink support carrier (16). Channels (37, 37B) with effective openings (40, 40A) therein are provided in a top surface (38) of the protective cover to facilitate applying an environmental sealing materail (45) through said channels and openings to the semiconductor diode dies of the electrical assembly as well as to various critical electrical interconnections (48) in the electrical assembly. By utilizing the mechanically protective cover to also provide for guiding the application of an environmental sealing material for the electrical assembly, extensive fixturing in providing a desired electrical assembly is minimized, the assembly is rendered more readily manufacturable, and protection of the assembly is provided even during the step of dispensing the sealing material.

Abstract: In a substrate mounting assembly (10) critical bonding pads (20) adjacent one lateral edge (21) of a ceramic substrate (11) are connected to semiconductor die (13) via wires (26). The substrate and die are mounted on a aluminum base carrier plate (12) which serves as a heat sink for the semiconductor die. A relatively rigid first adhesive (40) is applied in one area between the substrate and base carrier so as to effectively fix one lateral edge (21) of the substrate and the critical bonding pads (20) with respect to the base carrier, while a second adhesive (41), comprising an acrylic adhesive tape, bonds other areas of the ceramic substrate to the base carrier. At a lateral edge (23) of the substrate opposite to the lateral edge (21) adjacent the critical bonding pads, additional bonding pads (22) are provided and wires/conductors (27) connect these additional bonding pads to lead frame projections (28) from a non-conductive housing (29) fixed to the aluminum base carrier.

Abstract: A fixed volume receiving cavity (18) of a fuel injector (11) receives fuel from a fuel inlet valve means (23, 24) in accordance with the time duration(T.sub.A) of fuel metering control signal pulses (100). Injection occurrence control signal pulses ( b 101) actuate a compressed air inlet valve means (26-30) connected to the cavity to inject the contents of the cavity through an outlet valve (20) and into a combustion chamber (15) of an engine. The fuel metering pulses (100) are developed by a microprocessor (50). Circuitry (53-66; 70-79,66) separate from and external to the microprocessor receives the fuel metering control signal pulses and provides, in response thereto, the fuel injection occurrence control signal pulses. Use of a fixed volume receiving cavity in the injector, in combination with the time-controlled fuel inlet valve means, eliminates many mechanical likages required in most prior injectors.

Abstract: An integrated circuit sensor circuit (10) is disclosed which is operable in differential or single-ended modes at DC input potentials which can be below the integrated circuit substrate bias potential (ground). Substrate injection is prevented and the circuit is operable for input signals which can vary relatively widely with respect to the substrate bias potential. This is accomplished even though only a single polarity power supply (+5 volts) with respect to substrate bias potential is used for the integrated circuit. An input stage of an integrated circuit (16) comprises a pair of identical polarity transistors (23, 24) operated in a differential common base mode with an opposite polarity transistor (25) used to supply appropriate bias potential to the common base connection. This prevents substrate injection while maintaining a wide operative range for the sensor circuit.

Abstract: Several embodiments for mass airflow sensors are illustrated herein. In each case a sensing element (11) for the mass airflow sensor (10, 34, 50) is provided on a first portion (18) of a thin flexible film substrate (19) while an extension of this substrate provides integral electrical conductive metallizations (24) that connect the sensing element (11) to associated sensor electronic components (21) mounted on a second portion (23) of the film substrate remotely located from the first film portion. This eliminates the need for individual soldered wire connections to connect the sensing element to its associated electronics. In addition, housing portions (12, 13) for the sensor (10, 34, 50) mate together and provide protection for both the sensing element (11) and the sensor electronics (21) thereby providing an integral sensor module including the sensing element and its associated electronics.

Abstract: Inductor coil (13) of a relay (12) used to supply battery power to a power load (11) of a vehicle engine control system (10) is also used to provide a substantially higher than battery voltage (V.sub.Batt) boost voltage (V.sub.Boost) for vehicle control apparatus (20). Microprocessor (21) generates a control signal (V.sub.in) having a 10:1 duty cycle for control of current excitation of the coil (13) during an effective on logic state for the relay (12). During coil current interruptions during the on logic state, energy stored in the inductor (13) is utilized via a rectifier means (26 and 27) to provide the boost voltage. During the on relay state, a movable member (14) of the relay is maintained in its actuated position since current interruptions during the on state are shorter than the relaxation time required for the movable member to assume a nonactuated state.

Abstract: A technique for metallizing a substrate while providing stress relief for the metallization on the substrate is disclosed. Chrome conductive metallization (22) is deposited on a top surface (21) of an insulating glass substrate (20). An interior gold conductive metallization (23) is deposited on the chrome, and metallization (24) having a substantial nickel composition is deposited on the gold. Subsequently, an additional outer gold metallization (25) is provided on the nickel, and solder is provided on the additional gold metallization. Prior to the application of solder to the outer gold layer 25, the metallization layers are subjected to anodic bonding temperatures and voltage potentials. The gold layer between the nickel and chrome layers diffuses along the grain boundaries of the nickel and chrome layers, thus reducing the ability to transmit stress through these metallizations induced by the solder.

Abstract: An improved dual limit solenoid driver control circuit is disclosed in which solenoid current is sensed and provided as an input to two separate comparators (24, 25). Each comparator receives, during a solenoid pull-in (initial) period (T.sub.1), fixed maximum and minimum reference threshold levels which determine the maximum and minimum current limits (I.sub.max, I.sub.min) for solenoid current during initial pull-in excitation. Subsequently during a hold period T.sub.2 following the pull-in period, each of the comparators receives different maximum and minimum thresholds so as to establish holding solenoid current limits (H.sub.max, H.sub.min). The outputs of the compartors are connected as inputs to a set/reset flip flop (32) whose output controls the operation of a solenoid driver circuit (15). A monostable multivibrator (33) reacts to an initial control pulse (41) to produce a predetermined pull-in time pulse (43) that results in the maximum and minimum pull-in solenoid current limits.

Abstract: A display assembly for an LCD device is disclosed wherein the LCD essentially comprises an elongated horizontal plate. The LCD is mounted in a recessed portion of the top surface of a carrier made of light transmitting material with preferably the back surface of the LCD contacting the carrier top surface. Beneath the LCD, the carrier has an effective wedge-shaped portion, or at least an inclined planar surface of the carrier, and a light source is effectively positioned adjacent the carrier. At least one retainer member is utilized to mount the LCD to the carrier with edges of the carrier top surface recessed portion laterally surrounding and thereby laterally locating the LCD device with respect to the carrier. The preceding configuration allows the carrier to provide for backlighting of the LCD since the carrier serves as a light pipe in addition to providing mounting structure for the LCD.

Abstract: A pressure transducer (10; 10') having a silicon diaphragm (14; 14') and an insulating glass base (11; 11'). Surfaces (16, 12; 16', 12') of the diaphragm and glass base are anodically bonded together to form a hermetic seal for an internal reference cavity (24; 24') therein and also to provide hermetic protection for critical areas (70, 77; 70', 80, 81) on the silicon diaphragm. A plurality of semiconductor components are synthesized in an area (70; 70') in the silicon diaphragm. A plurality of conductors (71-73; 71'-73') are embedded (sealed) in the glass base so as to provide external electrical access to the semiconductor components without disrupting the hermetic seal provided between the silicon diaphragm and the glass base.

Abstract: In a solenoid fuel injection system, an output transistor (16) receives switching signals to control through current therein which is provided to a solenoid fuel injection coil (11) in series with a current sensing resistor (17). A current control circuit (12) provides pulse width modulation control of solenoid current by monitoring the voltage across the sensing resistor. The fault detection circuit provides separate fault signals for short circuits at either the first or second end terminals (E, H) of the solenoid coil. Separate voltage comparators (18, 23) monitor voltages at the first and second end terminals, and separate delay timers (20, 25) effectively gate the comparator outputs to indicate actual detected short circuits. Each of the fault detection signals sets a fault latch (22) which then acts to reduce current through the output transistor and coil. The fault latch is periodically reset.

Abstract: A voltage regulator (11) provides a pulse width modulated voltage regulator output (40) to a drive circuit (37) to provide field coil excitation for a voltage generator (15-17) providing a charging signal for a battery (14). The voltage regulator output determines on/off states of an FET power switching device (28) coupled in series with a field coil (17) across a maximum power source voltage potential V.sub.BAT corresponding to battery voltage. The drive circuit includes a charge pump (26, 35, 36) with a low capacitance capacitor (26) coupled and decoupled across a source of voltage potential at a rate determined by a high frequency signal (41), provided by the regulator, having a frequency substantially in excess of the frequency of the voltage regulator output. The drive circuit includes a pair of switches (21, 35) which alternately couple one terminal of the capacitor to either battery voltage or ground potential in accordance with the voltage regulator output.

Abstract: A two-way radio communications system includes a battery-operated portable unit and a base unit having a receptacle for receiving the portable unit when the portable unit is not in use. A security circuit in each unit allows communication with other units only upon the reception of an address code corresponding to an address code stored in the unit. When the portable unit is seated in the base unit receptacle, the batteries of the portable unit are recharged by current supplied by the base unit. At the same time, the address code of the base unit is entered into the portable unit by encoding circuitry which modulates the battery charging current in accordance with the address code. Circuitry within the portable unit demodulates the charging current to recover the address code for storage in the security circuit of the portable unit. The invention can also be used in systems where data other than address codes must be sent to a unit being charged.

Abstract: An improved solenoid driver control circuit is disclosed in which solenoid current is sensed and provided as an input to a comparator means comprising two separate comparators (24, 25). The comparator means receives a solenoid current sense signal (45) and maximum and minimum reference threshold levels which determine maximum and minimum current limits (I.sub.max, I.sub.min ; H.sub.max, H.sub.min) for solenoid current during initial pull-in excitation and subsequent hold excitation. Pull-in time (T.sub.1) is defined by a monostable multivibrator (33) reacting to a control pulse (41) to produce a predetermined pull-in time pulse (43) such that the pull-in time is independent of sensed solenoid current. During pull-in time a boost driver switch (53) applies high boost voltage to a power source terminal (16) which supplies solenoid current, and in response to achieving the maximum pull-in current limit (I.sub.max) lower battery voltage is provided at the power source terminal.

Abstract: A vehicle electronic transmission control system (10) having a servo control loop is disclosed. During the selection of a new gear, a countershaft (27) and transmission input drive shaft (13) are declutched from an engine crankshaft (11) and decoupled from a transmission output shaft (15). An error signal e is calculated representative of the difference between a desired speed related to input shaft speed (w.sub.1) and actual output shaft speed (w.sub.2). The error signal e is utilized to provide a servo control signal C having a first proportional term related to the square of the error signal, but having the polarity of the error signal, a second term related to the integral of the error signal multiplied by the absolute magnitude of the error signal and a third term related to the derivative of the error signal.

Abstract: An inexpensive semi enclosed alternator provides high power prolonged operation in environments having particle contamination in the ambient atmosphere. An alternator housing has front and rear housing portions, and a drive shaft carrying a rotor assembly is within the housing. A drive shaft extension from the housing holds a fan assembly. The rear housing portion has cylindrical sidewalls joined to a closed end portion 27 and forms an air sealed cavity except for an open end facing the front housing portion. The front housing portion comprises cylindrical sidewalls, having through-openings therein, which terminate in a first end opening 31, facing rear housing open end 28, and a substantially open second end opening 30 facing the fan assembly and the ambient atmosphere. Preferably rotor and stator assemblies, and rectifying diodes, are positioned within the housing substantially between the through openings and the closed end portion of the rear housing.

Abstract: A failsafe engine fuel control system is disclosed in which a primary control signal, normally a direct function of an engine manifold pressure sensor signal, is utilized by an electronic engine control microprocessor to calculate control signals for engine fuel injectors and engine spark apparatus. Pressure sensor failure detection apparatus is provided which, in the event of the engine manifold pressure sensor signal being non-representive of actual engine manifold pressure, results in making the primary control signal utilized by the microprocessor a direct function of at least an analog sensor signal representative of engine throttle position rather than engine manifold pressure. Preferably, in the event of a pressure sensor failure the primary control signal is calculated as a function of both a throttle position signal and an engine speed signal.

Abstract: A pressure sensor assembly includes a pressure transducer having a pressure displaceable diaphragm bonded to a base. Displacement of the diaphragm results in varying of electrical characterisitcs of the transducer in response to sensed pressure. Electrical output connections (wires) of the transducer extend from a central portion of a top surface of the base, which faces the diaphragm, to a central portion of a base bottom surface and peripheral portions of the diaphragm and base top surface are hermetically bonded together. The transducer is mounted on a carrier plate and integral extensions of the electrical output connections pass through holes in the carrier plate. A housing for the sensor assembly has an opening therein to provide access to the diaphragm by ambient atmosphere/fluid surrouding the housing.

Abstract: A flyback power supply is disclosed which includes a sample and hold feedback path. A pulse width modulation circuit provides control signals for a drive device that determines current excitation pulses for a primary winding of a transformer. A secondary winding of the transformer is connected to a rectifier circuit and provides a DC voltage signal at an output terminal. A selective feedback path is provided between the output terminal and a sense input terminal of the pulse width modulation circuit. The selective feedback path comprises a sample and hold circuit which provides for effectively coupling the output terminal to the sense input terminal at times during the storage of energy in the transformer, corresponding to an increase in transformer flux, and wherein at other times when the transformer flux is decreasing and energy is being transferred from the transformer to the rectifier circuit the feedback path effectively disconnects the output terminal from the sense input.