Abstract: An amplifier having a rail-to-rail common mode input range that can be used in low voltage power supply applications includes differential input and output stages, the output stage having first and second current paths. First and second output duplicating circuits are respectively connected in parallel with the first and second current paths in the differential output stage to duplicate the differential output. A circuit for detecting a common-mode voltage difference is provided between nodes of the first and second output duplicating circuits for developing a current related to the common-mode voltage difference. A current mirror circuit is connected to receive the current related to the common-mode voltage difference for controlling the current in the first and second current paths in the differential output stage.

Abstract: A molded device package supports a volatile memory chip and a replaceable backup battery for preserving data in the event of loss of main power supply. The package includes an external socket for receiving a replaceable backup battery which can be manually inserted into or removed from the socket after molding encapsulation and metal trim work have been completed. The socket is intersected by an exposure cavity which permits the positive and negative terminals of a backup battery to engage positive and negative finger leads. The positive and negative battery terminals are engaged by resilient terminal contact portions of the positive and negative finger leads which project into the exposure cavity. Socket shoulder portions and a retainer cap hold a backup battery within the socket and in electrical contact with the resilient terminal contact portions.

Abstract: A two-stage class-AB operational amplifier, that can be implemented either with bipolar or MOS transistors, includes a differential input circuit adapted to receive a differential input signal to produce an amplified differential output signal for application to first and second nodes. The differential input stage has a common-mode control circuit that produces first and second common-mode control voltages on the first and second nodes. The common-mode control voltages are combined with the amplified differential output signal on the first and second nodes to produce a first stage differential output signal. A high-swing output stage is connected to receive the first stage differential output signal. First and second current mirrors each have a mirror transistor to mirror an output current produced in response to the differential input signals on respective lines including the first and second nodes. The common-mode control circuit is in series with mirror transistors of the first and second current mirrors.

Abstract: A circuit automatically changes the gain in a PLL for driving a motor of the type having a motor speed signal that indicates the speed of motor rotation. The circuit includes a phase detector for sensing a phase difference between the motor speed signal and a reference frequency and for producing an output signal of duration proportional to the sensed phase difference. A counter counts clock pulses throughout the duration of the output signal, and a motor driving circuit drives the motor in response to the count reached by the counter. A source of clock pulses provides clock signals at first and second frequencies, the second frequency being lower than the first frequency, and a lock range sense circuit produces a sense signal output that indicates when the PLL is within a predetermined phase difference range.

Abstract: A circuit and method are provided for automatically adjusting a commutation delay from events indicating a position of a polyphase dc motor. The circuit includes a driver to supply drive current to selected stator coils of said motor. A sequencer is connected to control the driver to apply drive current to selected motor coils to rotate the motor. Motor position detecting circuitry is connected to detect the events indicating the position of the motor. A commutation delay circuit is connected to increment the sequencer in response to the detection of the events indicating the position of the motor detected by the motor position detecting circuitry. A circuit for adjusting the delay of said commutation delay circuit between each event and each sequencer commutation provides optimum motor commutation for maximum power efficiency.According to the method, drive current is supplied to selected stator coils of said motor in predetermined commutated sequences to rotate the motor.

Abstract: A windshield wiper system and method includes a dc motor for connection to drive a windshield wiper. A motor current switch controls current through a field winding of the dc motor. First and second speed selection switches are provided for selecting a speed desired for the windshield wiper. Means responsive to actuation of the first speed selection switch operates the motor current switch to control the current through the field winding of the dc motor for a first duty cycle, and means responsive to actuation of the second speed selection switch operates the motor current switch to control the current through the field winding of the dc motor for a second duty cycle different from the first duty cycle. A delay switch is provided, and a motor drive circuit responsive to a first activation of the switch enables the circuit for operating the motor to drive the windshield wiper once.

Abstract: An automotive charging circuit fault detection circuit includes a pseudo stator-phase signal generator and a stator-phase existence circuit for determining if a stator-phase signal is below a predetermined threshold. A pseudo stator-phase signal control circuit selectively applies the pseudo stator-phase signal to replace the stator-phase signal when the stator-phase existence circuit determines that the stator-phase signal is below the predetermined threshold. A voltage detector circuit continues the application of the pseudo stator-phase signal if an output voltage from the charging circuit is above a minimum voltage. A timer times a predetermined time the stator-phase signal is below the predetermined threshold to enable the voltage detection circuit, and a warning indicator provides a warning if the pseudo stator-phase signal is applied and if an output voltage from the charging circuit is below the minimum voltage.

Abstract: A door-stop alarm has a frame adapted to be affixed to an inside surface of a door, and a rotatable lever carried on the frame rotatably movable between a position engaging a floor surface and a position away from engagement with the floor surface. Means for are provided for translating rotational movement caused by slight opening of the door to upward movement of one end of the rotatable lever. An alarm switch is provided within the frame, and a projection on the rotatable lever engages the alarm switch upon upward movement of the rotatable lever. The rotatable lever comprises a portion to engage the alarm switch for turning the alarm circuit on and off when the lever is rotated to a position away from the position engaging the floor surface.

Abstract: An integrated circuit structure is presented that includes a substrate in which integrated circuit elements are constructed, a first interconnection metalization over the substrate interconnecting selected ones of the integrated circuit elements, and an oxide layer over the substrate and the first metal interconnection pattern. A glass layer over the oxide layer is substantially planar between portions that overlie the metalization and portions that do not over lie the metalization.

Abstract: A circuit and method for buffering a high output impedance voltage generator circuit to a low input impedance load circuit is described. Two emitter-follower stages are used with a load current feedback configuration so that the base to emitter voltages of all four transistors maintain a fixed relationship and therefore the output voltage presented to the load maintains a fixed relationship to the input voltage presented to the buffer amplifier circuit.

Abstract: A structure for protecting an integrated circuit against high supply line voltages is formed in an epitaxial silicon layer of one conductivity type on a semiconductor substrate of another conductivity type. A transistor is formed in the epitaxial layer to protect the integrated circuit against low range overvoltages. A highly doped region in the epitaxial layer on one side of the transistor of the same conductivity type as the expitaxial layer extends to the substrate. The highly doped region is connected to a reference potential and establishes a parasitic SCR with the transistor and substrate with a controllable breakover voltage above the protection voltage of the transistor.

Abstract: Regulator circuitry for connection to field coils of an alternator in an electrical system of a vehicle having a system voltage maintained by the alternator includes circuitry for providing a variable drive to the field coils of the alternator, and circuitry for generating a velocity signal related to a rotational velocity of a driven shaft of the alternator. The regulator circuitry also includes circuitry for producing a deviation signal when the system voltage deviates more than a predetermined amount from a predetermined value, and circuitry responsive to the deviation signal to vary the field coil drive to the alternator at a rate dependent upon the velocity signal. In addition a method is presented for regulating the voltage delivered by an alternator in an electrical system having a system voltage maintained by the alternator.

Abstract: Synchronization of the output of an internally-driven VCO to an exterior clock signal is obtained by using the exterior clock signal to re-start the VCO at every exterior clock pulse, until the pre-set VCO frequency is reached. At that point, the restarting of the VCO ceases, and the VCO locks onto the internal signal it is designed to track. One application of this circuit is for enabling a smooth transition between open-loop, ramp-up of a polyphase DC motor to closed loop operation. Implementation of the circuit described phase-synchronizes the output of a phase-switching PLL loop, which is tracking the back emf of the motor, to the external clock used for motor ramp-up, so that there is no "jolt" in the motor at the transition from open-loop to closed-loop operation of the motor.

Abstract: A circuit for operating a polyphase dc motor, for example of the type having a plurality of "Y" connected stator coils, has circuitry for unambiguously determining the actual instantaneous position of the rotor of the motor, circuitry for determining a desired rotor position precedent to executing a desired commutation sequence, and circuitry for executing the desired commutation sequence when the circuit for determining the actual instantaneous position of the rotor detects that the rotor is actually in the desired rotor position. The circuitry for unambiguously determining the actual instantaneous position of the rotor includes a back emf amplifier switchably connected to at least one floating coil in accordance with sequence signals received directly from a sequence generator, and circuitry for determining when the voltage received by the back emf amplifier crosses zero from a predetermined direction.

Abstract: A transparent glazing material with a plurality of concentrating lenses on its top surface such that incident radiation on the top surface is focused to pass through apertures in a corresponding plurality of integral reflective surfaces with a plurality of segments of thermal insulating material arranged directly beneath the reflective surfaces along the bottom of the transparent material in a pattern with apertures in the reflective and insulating materials located directly below each lens such that incident radiation on the top surface is focused by the lenses and passes through the holes in the reflectors and insulation and out the bottom. Radiation in the direction opposite to the incident radiation will strike the bottom of the reflectors and be reflected back from the bottom.

Abstract: A circuit for providing a signal proportional to the average current supplied to the coils of a motor operated in both linear and PWM modes includes a sense resistor across which a voltage representing the current flowing supplied to said coils is developed. The voltage is selectively applied to an output circuit which operates as a low pass filter circuit when drive current is supplied to the coils and as a voltage hold circuit when drive current is not supplied to the coils. The output circuit includes an amplifier connected to receive a voltage produced by the sense resistor when the motor is operated in the linear mode, and a capacitor and a resistor connected in parallel, the capacitor and resistor being connected between an input and an output of the amplifier to operate as a low pass filter circuit.

Abstract: A method for starting a polyphase motor of the type having a plurality of stator coils and a rotor includes the steps of measuring the rise time of current on each of the stator coils, determining from the rise time measurement the position of the rotor, and determining a coil to apply a voltage to produce maximum startup torque of the motor. Any position ambiguities are resolved by determining the direction of rotation of the motor by applying a voltage to the determined coil sufficient to produce at least a slight rotation of the rotor, remeasuring of the rise time of current on at least a plurality of the rotor coils, and determining a difference between the rise time measurement and remeasurement. The difference indicates the direction which the rotor was rotated.

Abstract: A brushless direct current motor with minimized current ripple and a method is disclosed. The motor system includes commutation current control for controlling the rate of turn-off of the current flowing in the phase being turned-off while simultaneously controlling the rate of turn-on of the current flowing in the phases being excited. This minimizes torque ripple in the motor.

Abstract: A circuit for resynchronizing the rotor of a polyphase dc motor having "Y" connected stator coils and a moving rotor has circuitry for determining the actual instantaneous position of the rotor, and circuitry for determining a desired rotor position precedent to executing a desired commutation sequence.

Abstract: A buffer circuit includes an input amplifier connected to receive an input signal and an output amplifier connected provide an output signal. A differential amplifier is connected to also receive the input and output signals and to provide an output related to the difference between the signals to maintain a desired relationship between the input and output signals. The buffer circuit can be configured so that the signal from the differential amplifier is provided either to the input or the output amplifier, and can be accomplished in either bipolar or BICMOS technologies. The combination of the open loop and differential type buffer amplifiers, retains the best features of both, with the excellent speed performance of the open loop circuit as well as the enhanced accuracy of the differential amplifier circuit.