Abstract: A drivetrain (48) for an electric passenger vehicle (10) includes a battery (40) for energizing a single-phase A.C. traction motor (18) which drives a ground engaging wheel (12) through a multispeed transaxle (20). The motor is characterized by an external ferrite permanent magnet rotor (26) drivingly engaging an input shaft (32) of the transaxle. The motor is controlled by an inverter circuit (44) and a control circuit (46) which generates switch command signals to reciprocally actuate power transistors (56) and (62) within the inverter circuit as a function of operator demand, rotor position and rotor speed. The control circuit includes a motor positioning circuit (442) which toggles the motor current when the rotor speed falls below a predetermined level to dither the rotor about a park position for a predetermined period. A prestart rotor positioner (224) is provided to mechanically lock the rotor in its park position to ensure the availability of a high electrical starting torque.

Abstract: A drivetrain (48) for an electric passenger vehicle (10) includes a battery (40) for energizing a single-phase A.C. traction motor (18) which drives a ground engaging wheel (12) through a multi-speed transaxle (20). The motor is characterized by an external ferrite permanent magnet rotor (26) drivingly engaging an input shaft (32) of the transaxle. The motor is controlled by an inverter circuit (44) and a control circuit (46) which generates switch command signals to reciprocally actuate power transistors (56 and 62) within the inverter circuit as a function of operator demand, rotor position and rotor speed. The control circuit includes a motor positioning circuit (442) which toggles the motor current when the rotor speed falls below a predetermined level to dither the rotor about a park position for a predetermined period. A pre-start rotor positioner (224) is provided to mechanically lock the rotor in its park position to ensure the availability of a high electrical starting torque.

Abstract: Tire pressure monitors (10) are incorporated in vehicles (12) having pneumatic tires (15) to continuously or periodically measure air pressure within each tire and to alert the driver should the pressure in any of the tires fall below a predetermined value. A passive transponder (22) is affixed within the drop center (41) of each wheel (17) and includes a pressure sensing switch (36). An RF transmitter (46) centrally located within the vehicle body interrogates each transponder, either serially or simultaneously. Each transponder, in turn, reflects a predetermined harmonic of the RF signal back to a receiver (48) as a function of the state (open or closed) of its associated pressure switch. The receiver then outputs a signal to a processor/display unit (50) to activate an alarm or indicating device (58).

Abstract: A viscous fan clutch (10) is typically employed in a fan drive mechanism within a truck or automobile. A shaft (12) driven by the engine, rotates a clutch member (24) within the fan drive. The clutch member is arranged for fluid engagement with a body member (42) for the transmission of torque thereto when the fluid is disposed in an operating chamber (70) defined by complimentary shear surfaces (30 and 56) in the clutch and body members. During relative rotation between the two members, fluid is pumped from the operating chamber to a storage chamber (76) through a return passage (111). Fluid is returned to the operating chamber via bleed ports (118). The return passage and bleed ports are selectively restricted by an electromagnetically controlled valve (112) which taps the kinetic energy of the rotating members. A control system (132) senses vehicle coolant temperature and actuates the valve as a function thereof.

Abstract: An inverter (34) which provides power to an A.C. machine (28) is controlled by a circuit (36) employing PWM control strategy whereby A.C. power is supplied to the machine at a preselectable frequency and preselectable voltage. This is accomplished by the technique of waveform notching in which the shapes of the notches are varied to determine the average energy content of the overall waveform. Through this arrangement, the operational efficiency of the A.C. machine is optimized. The control circuit includes a micro-computer which calculates optimized machine control data signals from various parametric inputs and during steady state load conditions, seeks a best V/HZ ratio to minimize battery current drawn (system losses) from a D.C. power source (32). In the preferred embodiment, the present invention is incorporated within an electric vehicle (10) employing a 144 VDC battery pack and a three-phase induction motor (18).

Abstract: A combustible mixture composed of a flowing fuel and gaseous oxygen is ignited by exposing one or both of the constituents of the mixture to a region of corona discharge in order to generate molecular radicals which subsequently combine with radicals of the other constituent to initiate combustion. The apparatus includes at least two electrodes (14 & 16) having a voltage potential impressed thereacross to generate a region of intense electric field and means to maintain the resulting voltage-current characteristic relationship within a corona discharge region of operation (42).

Abstract: An acoustic fuel injector system comprises a DC-to-DC converter (14) for supplying a regulated voltage to a frequency controlled oscillator (16) which drives the injector valve (18) or valves. The converter comprises a flyback oscillator (28) including a switching transistor (32) and a transformer (34, 36) for applying rectified current pulses of variable amplitude and occurrence rate to an output capacitor (42). A variable impedance device (50) in the input circuit to the flyback oscillator is controlled by a feedback signal (68) from the output circuit (30) to vary the cycle rate of the flyback oscillator to maintain output voltage at a desired value. The feedback signal is coupled to the oscillator control circuit input to effect a variable regulated output voltage which is relatively high upon injector turn-on but decays to a lower operating level thereafter.

Abstract: A drivetrain (48) for an electric passenger vehicle (10) includes a battery (40) for energizing a single-phase A.C. traction motor (18) which drives a ground engaging wheel (12) through a multi-speed transaxle (20). The motor is characterized by an external ferrite permanent magnet rotor (26) drivingly engaging an input shaft (32) of the transaxle. The motor is controlled by an inverter circuit (44) and a control circuit (46) which generates switch command signals to reciprocally actuate power transistors (56 and 62) within the inverter circuit as a function of operator demand, rotor position and rotor speed. The control circuit includes a motor positioning circuit (442) which toggles the motor current when the rotor speed falls below a predetermined level to dither the rotor about a park position for a predetermined period. A pre-start rotor positioner (224) is provided to mechanically lock the rotor in its park position to ensure the availability of a high electrical starting torque.

Abstract: A pneumatically operated speed governor (26) moves an engine throttle member (10) for controlling the speed of a vehicle. The governor includes a pneumatically operated actuator having an output connected to the engine throttle member. A pivotally mounted valve member (44) is positioned intermediate a vacuum supply orifice (46) and an atmospheric air orifice (48) and supplies a pneumatic signal to the actuator. An internal speed sensor (82) responsive to vehicle speed has an output member (100) which reacts against an improved, self-wiping minimum speed switch (102) and a set-speed control member (52) which in turn reacts against the pivotally mounted valve member (44) for varying the position of the valve member as the vehicle speed tends to fall below or rise above a predetermined set speed.

Abstract: An inverter is connected between a source of DC power and a three-phase AC induction motor, and a microprocessor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .theta., where .theta. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands for electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor.

Abstract: A heating and air conditioning control system having a compressor clutch cycle control feature for controlling the in-car temperature of a vehicle passenger compartment is disclosed. The system comprises an automatic temperature control (ATC) sensor (32) which provides a modulated vacuum control signal for a vacuum motor (38). The vacuum motor has an output which adjusts a biasing element in an electrical switch (82), resulting in on/off duty cycling of an electrically energizable clutch (28) which transmits power from the vehicle engine to the air conditioner compressor (26). The percentage of time that the compressor is on versus the time off is a function of the control signal which is, in turn, a function of the ambient, in-car, and manually selected set point temperatures sensed by the ATC sensor.

Abstract: A hydraulic lash adjusting tappet 10 for use in engine valve gear of the direct acting type having one end of the tappet contacting the end of the combustion chamber valve stem 26 and the other end contacting the camshaft lobe 16. The tappet has the body 40 formed with a tubular wall portion 42 having an inwardly extending web portion 44 intermediate the ends thereof with a tubular hub 46 disposed therewithin formed integrally with the web and extending axially therefrom. A cam face disc member 18 is attached about the periphery thereof to one end of the tubular wall. A plunger means 50 is slidably received in the tubular hub and includes a piston 64 slidable therein forming a high pressure chamber 86 within the plunger remote from the cam face and having therein one-way valve means for admitting fluid to the chamber for lash adjustment. An annular retainer 56 is received over the outward end of the hub and a passage 84 is provided through the tubular wall portion for communicating fluid to the reservoir.

Abstract: An acoustic fuel injector-atomizer comprising a horn (74) actuated by piezoelectric crystals (28a, 28b) to form a resonant structure (18) excited by an oscillator signal. The oscillator (16) which generates the excitation signal is self-tuned to the resonant frequency of the structure (18) by means of a first transformer coupling (66, 56) which provides a feedback path between the structure (18) and the oscillator transistor (24) and a second transformer coupling (68, 56) which provides a compensation signal representing static capacitance of the crystals (28a, 28b). The compensation signal is subtracted from the feedback signal of the structure (18) so as to eliminate the static capacitance component as an error source in the self-tuning function.

Abstract: A viscous fan clutch (10) is typically employed in a fan drive mechanism within a truck or automobile. A shaft (12) driven by the engine, rotates a clutch member (24) within the fan drive. The clutch member is arranged for fluid engagement with a body member (42) for the transmission of torque thereto when the fluid is disposed in an operating chamber (70) defined by complimentary shear surfaces (30 & 56) in the clutch and body members. During relative rotation between the two members, fluid is pumped from the operating chamber to a storage chamber (76) through a return passage (111). Fluid is returned to the operating chamber via bleed ports (118). The return passage and bleed ports are selectively restricted by an electromagnetically controlled valve (112) which taps the kinetic energy of the rotating members. A control system (132) senses vehicle coolant temperature and actuates the valve as a function thereof.

Abstract: An inverter is connected between a source of DC power and a three-phase AC induction motor, and a micro-processor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .THETA., where .THETA. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands of electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor.

Abstract: A low pressure drop hot film/swirl air flowmeter (10) for an automotive engine is disclosed. The flowmeter includes a main air flow passage (18), a relatively small venturi (20) disposed within the passage for receiving a portion of the air flow, a constant temperature thermal anemometer (48) positioned to sense the air flowing in the throat (44) of the venturi, and a set of swirl vanes (22) operative to impart a swirl to the remainder of the air in the main passage, thereby creating a reduced pressure at the venturi outlet for forced aspiration therethrough without appreciably increasing the pressure drop across the flowmeter. The anemometer includes a bridge circuit (114), one leg of which comprises a resistive sensor (70) within the throat of the venturi. In the preferred embodiment of the invention, an ambient air temperature sensor (72) is included as another of the legs of the bridge to provide temperature compensation for the flowmeter.

Abstract: Tire pressure monitors are incorporated in vehicles having pneumatic tires (14) to continuously or periodically measure the air pressure within the tires and to alert the driver should the pressure in one of the tires fall below a predetermined value. A self-contained battery powered rf transmitter unit (10) is affixed within the drop center (22) of each wheel (12) and includes a pressure sensing switch (84). The battery is contained within a housing (20) mounted to the external surface of the wheel adjacent a fill valve (30) through which electrical wires (50) are routed to the transmitter (11). The transmitter employs a programmable unijunction transistor (PUT) timer (56) which generates a pulse every 33 seconds when the air pressure within the tire is above a prescribed value. A receiver (13), located in the passenger compartment of the vehicle, receives the signal(s) from the transmitters and counts the number of signals received over a given time period established by a second internal PUT timer (266).

Abstract: A low pressure drop hot film mass air flowmeter (10) for an automotive engine is disclosed. The flowmeter includes a main air flow passage (20), a fixed contoured flow nozzle (22) disposed in the main air flow passage to establish a localized pressure differential thereacross and, a closed circuitous recirculation path (40) disposed adjacent the main air flow passage and in fluid communication therewith through an inlet port (42) disposed upstream of the flow nozzle and an outlet port (44) disposed downstream from the flow nozzle. Pressure differential at the ports establishes a substantially laminar control flow therebetween within the recirculation path which, in turn, by viscous action, establishes a recirculation flow (67) within the recirculation path. A constant temperature thermal anemometer (54) includes a hot film probe (56) and a temperature compensating probe (58) positioned to sense the recirculating air within the recirculation path.

Abstract: A quick vent response valve (12) is fluidically series connected between a vacuum regulator valve (14) and an exhaust gas recirculation valve (16) which comprises a fluid pressure control system (10). The quick response valve operates to vent the system more quickly than if the system were vented through the vacuum regulator valve itself by employing the modulated control signal from the vacuum regulator valve as a pilot signal. The quick response valve improves response time of the vacuum system when venting from a high to a low vacuum level by momentarily displacing a valve element (56) disposed within a housing (18) to establish a nonrestricting flow path to atmosphere.

Abstract: A pneumatically operated speed governor (26) moves an engine throttle member (10) for controlling the speed of a vehicle. The governor includes a pneumatically operated actuator having an output connected to the engine throttle member. A pivotally mounted valve member (44) is positioned intermediate a vacuum supply orifice (46) and an atmospheric air orifice (48) and supplies a pneumatic signal to the actuator. An internal speed sensor (82) responsive to vehicle speed has an output member (100) which reacts against an improved, self-wiping minimum speed switch (102) and a set-speed control member (52) which in turn reacts against the pivotally mounted valve member (44) for varying the position of the valve member as the vehicle speed tends to fall below or rise above a predetermined set speed.