Abstract: A kelvin current sensing circuit in an integrated control circuit that controls the current flowing through the driving coils of a polyphase DC motor. The invention provides for adjusting the voltage to the lower driver transistors of the control circuit by having the kelvin current sensing occur internally within the chip. A ground compatible differential amplifier circuit is used in one embodiment. Each of the lower transistors are connected to the base of respective PNP transistors, the emitters of which being connected together to control one side of the differential amplifier. A control voltage is applied to the other side of the differential amplifier. The output of a comparator, that is connected to the differential amplifier, is used to control the operation of the lower driver transistors. Therefore all of the sensing is done internally in the semiconductor chip. The voltages are taken at the source of each of the lower transistors.

Abstract: A fuel delivery system in an engine is provided with a fuel flow stabilizing device for instantaneously providing a precise amount of fuel to the engine according to a particular fuel demand. The fuel flow stabilizing device has an accumulator device which stores a reserve amount of fuel under pressure and supplies or accepts excess fuel in response to a change in fuel pressure in the fuel delivery system. The accumulator device allows a simpler fuel pump motor and control system to be used as fuel pump response time requirements are reduced.

Abstract: A circuit and method for detecting when the back emf of a motor coil passes a predetermined level includes circuitry for providing a voltage proportional to the back emf of the motor coil, and circuitry for providing a voltage proportional to a reference potential. A first bias voltage is added to the voltage proportional to the back emf to produce a first added voltage, and a second bias voltage is added to the reference potential when the back emf of the motor coil is expected to change in a predetermined direction to produce a second added voltage. A comparator produces an output change when the first added voltage becomes larger than the second added voltage at the predetermined level.

Abstract: A PTAT current source has first and second current mirror circuits, each comprising a cascode transistor, an output transistor in series with the cascode transistor, and a base current compensating transistor having a control element connected to the cascode transistor on a side away from the output transistor, and a current flow path element connected to a current control element of the output transistor, the cascode transistors of the first and second current mirror circuits having differently sized emitter areas. A resistor is connected between the cascode transistors of the first and second current mirror circuits across which a differential current is developed. An output circuit develops a current in the output transistor of the second current mirror circuit. In one embodiment, a third mirror circuit is provided, to cancel a portion of an emitter current flowing in the output transistor of the second current mirror circuit.

Abstract: A full wave rectifier includes an amplifier having a minus input, a plus input and an amplifier output; an input resistor connected between a circuit input and the minus input; and a current bridge having an output terminal connected to the circuit output, a first terminal connected to the minus input and a second terminal connected to the amplifier output. The current bridge includes a first current mirror circuit and a second current mirror circuit. The first current mirror circuit includes a first current source and a second current source, a source end of each current source of the first and second current sources being connected to the first terminal, a drain end of the first current source being connected to the second terminal and a drain end of the second current source being connected to the output terminal.

Abstract: A logarithmic amplifier has first and second mirror circuits, each having active transistors interconnected by a resistor. The current input is applied within one of the mirror circuits so that a logarithmic function thereof is generated for output by an output current mirror circuit. The mirror circuits are similarly constructed with an active transistor, a cascode transistor, and a base current compensating transistor. The cascode and active transistors are connected in series between an input node and a reference potential, or ground, with the base current compensating transistor connected between a supply voltage source and a base of the active transistor. The base of the base current compensating transistor is connected to the reference current input node. Through modification of the basic circuit by injection of an input current to the active transistor with respect to the reference potential, an exponential converter is presented.

Abstract: A wideband current multiplying divider circuit that produces an output current of any ratio to the input current has a first bipolar transistor and a first reference current source connected in series between a supply voltage and ground. A second bipolar transistor and a second reference current source are also connected in series between the supply voltage and around. A summation current source is connected at one side to ground and at the other side to a divided current path. A first resistor is connected in series with the station current source between a base of the first bipolar transistor and ground, and through which an input current can be connected to flow. A second resistor is connected in series with the summation current source between a base of the second bipolar transistor and ground, and through which an output current can be connected to flow.

Abstract: A method and apparatus for operating a polyphase dc motor selectively in dual-coil or uni-coil commutation modes. The motor has a plurality of "Y" connected driving coils connected together at a center tap. Each driving coil has an input node at an end opposite the center tap, and is driven by a switch pair. Each switch pair is arranged for connection in series across a power supply voltage, and has a node between each switch connected to a respective one of the coil input nodes. An additional pair of switches are provided for connection in series across the power supply with a connection node between each switch connected to the center tap. A circuit is provided to operate the switches to cause a driving current to be passed between sequentially selected pairs of the driving coils for an initial start-up time.

Abstract: A circuit for increasing the reverse breakdown voltage of a bipolar transistor that provides drive current to an inductor has a voltage control transistor connected between the collector and base of the bipolar transistor, having a control element connected to one end of the inductor. The circuit can be fabricated as a portion of an integrated circuit formed on a single semiconductor substrate. Also disclosed is a method for increasing the emitter-collector breakdown voltage of a bipolar transistor in which the base and collector of the bipolar transistor are shorted when the emitter-collector voltage exceeds the breakdown voltage by turning on a transistor connected between the base and collector of the bipolar transistor.

Abstract: A vacuum cleaner attachment has an attachment cylinder and a plate enclosing one end of the attachment cylinder. A semi-rigid tube is attached to and extends from a front side of the plate. A flexible sheet is attached at a centrally located edge to a circumference portion of the attachment cylinder. A hook and loop fastener is attached to outside edges of the flexible sheet so that when the back side of the attachment cylinder is placed over an end of a vacuum cleaner hose, the flexible sheet may be wrapped around the vacuum cleaner hose and the hook and loop faster may be engaged to secure the attachment cylinder in place. Ridges may be provided along a central portion of a length of the tube to adjust the rigidity to the central portion of the tube, and top and bottom scrapper wings are attached adjacent an end of the tube away from the attachment cylinder.

Abstract: A method and circuit for braking a forward rotation of a rotor of a polyphase DC motor. A commutation sequencer is incremented by several phases to produce an incremented commutation sequence to produce a magnetic flux vector that lags a magnetic pole of the motor. Driving currents are applied to coils of the motor in accordance with the incremented commutation sequence to brake the rotor. The method is implemented in a circuit that has a sequencer for incrementally generating sets of commutation signals to select stator coils for energization to rotate the rotor. A power stage to which the commutation signals are applied energizes the selected coils in accordance with the commutation signals. A circuit interrupts the energization of the selected coils and the commutation sequence is altered to produce a sequence that produces a negative torque on the rotor.

Abstract: A circuit for sensing the current delivered to a load, or multiple loads, such presented by a polyphase DC motor, without significantly dissipating the energy delivered to the load, has a predriver circuit and a power delivery circuit for each load. The predriver circuit is connected in a series path between a voltage source and a control element of the power delivery circuit, and the power delivery circuit is connected between a connection node and a respective one of the loads. A sensing element is connected in a series path between the source of voltage and the power delivery circuit connection node. In a preferred embodiment, the sensing element is a resistor, the predriver circuit is a PNP transistor, and the power delivery circuit is an NPN transistor. The PNP and NPN transistors are connected to form a pseudo-Darlington transistor pair, with the collectors of the NPN transistors interconnected to enable a single sense resistor to be used to sense the current in each of the loads.

Abstract: A current source for producing a current that is proportional to absolute temperature (i.e., "PTAT") is disclosed. The current source is based upon a circuit having a pair of current mirrors, one based upon MOS transistors and the other based upon bipolar transistors, where each of two legs in the current source include the series connection of one of the MOS transistors with one of the bipolar transistors. Further included in the disclosed circuit is a series connection of three MOS startup transistors, useful in starting up the current source in a non-critical manner. A startup current source, sourcing a non-critical startup current, turns on one of the MOS startup transistors that is connected in current mirror fashion with the MOS transistor current mirror, turning on both current mirrors. As the output current increases, the current through the MOS startup transistors also increases, until equilibrium is achieved.

Abstract: A digital-to-analog converter has a bias block that provides first and second voltage outputs, and a bit cell having a switch for selectively connecting either a first or a second summing node to a current flow path depending upon the state of a binary input signal. An output bipolar transistor and a current source are connected in series between a supply voltage and a reference potential. A first MOS transistor is connected in the current flow path with its gate connected to the bipolar transistor. A base current compensating second MOS transistor is connected between the supply voltage and a base of the output bipolar transistor with its gate connected to the first voltage output of the amplifier. A resistor is connected between the base of the output bipolar transistor and the second voltage output of the amplifier. When a plurality of bit stages are provided, the resistor of each of the plurality of bit cells is sized according to a position of its associated cell in the bit order.

Abstract: A cascode mirror circuit, referred to as a "half-cascode mirror", or "HCM" has first (cascode), second (active), and third (base control) transistors. The cascode and active transistors are connected in series at a first node, the series being connected between a second node and a reference potential. The cascode transistors has its base connected to a second reference voltage. The base control transistor is connected between the supply voltage and a base of the active transistors, with its base connected between the first reference current source and the cascode transistor. Depending upon the selection of input and output signal locations, the circuit can perform various functions, including the generation of an output circuit that varies linearly, logarithmically, or exponentially with an input current, and the generation of an output voltage that varies linearly with the input current.

Abstract: A voltage multiplier has first, second, and third capacitors, each having first and second plates. The multiplied output voltage is developed between the first and second plates of the third capacitor. First and second diodes are connected respectively between first plates of the first and second and the second and third diodes. A switch is connected between the supply voltage and the first plate of the first capacitor. First and second inverters are provided, each having an input, and having an output connected respectively to the second plates of the first and second capacitors. The first inverter is connected to the supply voltage to produce the supply voltage as an output of the first inverter when a low state is applied to the input of the inverter. The second inverter is connected to the first plate of the first capacitor to produce a voltage from the first capacitor as an output of the second inverter when a low state is applied to the input of the second inverter.

Abstract: An apparatus for controlling a throttle of an internal combustion engine of a vehicle receives a signal related to an actual position of the throttle, and a target throttle position signal produced in response to a condition of the vehicle, such as loss of traction of one or more driving wheels. A polyphase motor is connected to control the position of the throttle. A circuit, such as a programmed digital computer, is also provided that is responsive to the target throttle position signal for simultaneously applying driving signals to at least two windings of the polyphase motor to cause the polyphase motor to move the position of the throttle until the signal related to the actual position of the throttle indicates that the throttle is at a position indicated by the target throttle position signal.

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 circuit and method for driving an inductive load has a first transistor with a current flow path connected to provide drive current at an output node to the inductive load, and a control element for controlling the current in the first current flow path. The control element is adapted for connection to receive a control signal for turning the current in the first current flow path of the first transistor on and off. A second transistor has a current flow path connected between the output node and the control element of the first transistor, and has a control element for controlling the current in the current flow path. A capacitor is connected between the control element of the second transistor and a reference potential, the capacitor being much larger than an inherent capacitance at the control element of the first transistor divided by a current gain of the second transistor. Finally, a rectifier is connected between the output node of the first transistor and the capacitor.

Abstract: The regulation of the output voltage of a voltage multiplier driven by a ring oscillator, an inverter of which is substituted by a NOR gate for providing a terminal through which stopping the oscillation, is effected by controlling the oscillation frequency in function of the current delivered by the voltage multiplier by means of a transistor T1 working as a current generator connected in series with a regulating chain of series-connected diodes by biasing the gate of the transistor with a constant voltage Vref, thus imposing a reference current Iref through the transistor. The voltage signal across the transistor is fed to the input of a first inverter with a preset triggering threshold and the output signal of the inverter is fed through an amplifying and phase-regenerating stage to said terminal for stopping the oscillation of said NOR gate of the ring oscillator.