Sendyne Corporation

Usar Systems, Inc.

Other

Semtech Corporation

Sensata Technologies, Inc.

Semtech New York Corporation

Ioannis Milios

Victor Marten

Wei Wang

Nicolas Clauvelin

Carl Oppedahl

Aleksandar Prodic

Mahmoud Shousha

Tadashi Okuto

Dimitrios Korres

Jun Liu

Mike Paloyan

Robert C Melville

An isolation monitoring approach according to the invention is defined with respect to first and second battery connection positions, each of which is not tied to a chassis. First and second respective resistor strings, each having a first end and a second end, are each connected at their first end to the respective first and second battery connection positions. The first and second resistor strings are each connected at their second end to the chassis. In each of the first and second resistor strings, an optically-controlled MOSFET relay is connected across part of the resistor string. Connected to each of the resistor strings, at a point between the MOSFET relay and the chassis, is a respective voltage measurement circuit connected to measure voltage relative to the chassis. In operation, the MOSFETs associated with the resistor strings can be turned on and off. This brings about an excitation signal with respect to the resistor strings, and the voltage measurement circuits can measure the voltages during the time of the excitation signal, comparing them with the voltages in the absence of the excitation signal. This permits arriving at an inferred value for isolation loss along a modeled leakage path between the associated battery connection positions and the chassis. In the event of an isolation failure, the event can be annunciated.

Isolation monitoring

Wide deployment of high voltage battery systems in traction, industrial and renewable energy installations is raising the concerns for human safety. Exposure to hazardous high voltages may occur due to deterioration of insulation materials or by accidental events. It is thus important to monitor for such faults and being able to provide timely warnings to affected persons. For this purpose it has become mandatory for electrified passenger vehicles (CFR 571.305) to maintain high isolation values which can be continuously monitored by electrical isolation monitoring devices. The task of monitoring isolation resistance within the electrically noisy car environment is not a trivial task and the solution to this problem has become quickly a field of research and innovation for all affected industries.

Isolation monitoring device and method

A complete model numerical solver resides on an embedded processor for real time control of a system. The solver eliminates the need for custom embedded code, requiring only model equations, definition of the independent and dependent variables, parameters and input sources information as input to solve the model equations directly. Through elimination of the need for custom code, the solver speeds up the model deployment process and provides the control application sophisticated features such as Automatic Differentiation, sensitivity analysis, sparse linear algebra techniques and adaptive step size in solving the model concurrently.

Model numerical solver for system control

Cell balancing aims to prolong the battery operating life by equalizing the Electro Motive Force (or Open Circuit Voltage) of the participating cells. Even perfectly balanced cells though will exhibit different output voltages because of differences in their internal impedances. The difference in voltage will depend on the load current frequency and intensity. A method is described for re-distributing charge in such a way so when the worst (from the point of view of voltage spread) possible load conditions occur, cells will have similar outputs and none will cross the under-voltage threshold causing a premature shut down of the battery.

Charge redistribution method for cell arrays

What is described is a battery management architecture that eliminates previously described problems of the previous solutions and compensates for the extra cost of a cell-balancing circuit. These advantages are achieved by integrating the voltage step-up and balancing functions as well as charging functions inside a single converter topology. Instead of providing the entire output voltage and power, the converter in this configuration is merely assisting the battery by providing a portion of the power delivered to the load, rather than the entirety of the power delivered to the load. This portion of power is proportional to the difference between the output and the battery pack voltages.

Assisting converter

A type of protection and cell conditioning circuit is proposed that partly uses the typically existing hardware present in traditional cell-protection circuits and that can achieve an optimum state of charge for the individual cell independently from the actions of the external battery charger. For minimum cost, the proposed circuit and system can solve the battery-cell-balancing problem, while optimizing the performance of the battery pack and while simultaneously enhancing the safety of the battery pack. Multiple battery cells can be communicatively combined to form large batteries. Information from and commands to each of the individual battery cells can be relayed through a low-power serial bus in order to form 'intelligent' and optimally managed battery systems.

Battery cell protection and conditioning circuit and system

In a direct methanol fuel cell, fuel efficiency is maintained by periodically adding a higher methanol concentration mixture through a cartridge into the primary fuel container. The cartridge replenishes methanol and partial water losses due to the consumption of fuel in the power generating process. In a typical system, the fuel replenishment mechanism is controlled through an electronic apparatus that monitors the power conversion process and is capable of predicting remaining operating capacity.

Fuel supply method for direct methanol fuel cell

A conveyor specialized to convey people, and more particularly a conveyor which may serve as a conventional staircase, comprises treads that can individually raise and lower by the amount of the tread rise. To ascend, a user stands on the lowest level, and the tread lifts to match the height of the next tread. The user steps forward to the next tread. That tread likewise lifts to match the height of the next tread, and so on. In this way the user is able to ascend the height of the staircase without having to step up. A corresponding process permits descending the height of the staircase without having to step down. The conveyor can work even if the staircase winds or curves or goes around corners. Optionally a platform is caused to move laterally from each step to the next, so that the user need not even step forward during the process.

Conveyor for conveying people

A wireless host is used with a computer having a BIOS, an operating system, a serial bus interface coupled with the BIOS, the wireless host operating under a protocol that functions only in the presence of a corresponding wireless communications driver in the operating system, and the BIOS characterized in that human interface device information received via the serial bus interface is made available to the operating system by means other than the wireless communications driver. Human interface device information is received via the wireless host. Depending on a predetermined condition, the human interface device information is passed to a wireless communications driver in the operating system, or is passed to the serial bus interface and is made available to the operating system by means other than the wireless communications driver. The predetermined condition may be the absence of the wireless communications driver, or for example may be the determination that the human interface device information is an escape sequence. In this way, user communications to the computer can be robust even in the event of operating system or software failure.

Wireless host with improved roustness and boot capabilities

A system is described in which the Master can stop its clock and go into a low-power state (for power conservation reasons) at arbitrary times. Before going into the stopped-clock or low-power mode, the Master checks that the serial bus is idle (defined as both Clock and Data lines being &ldquo;High&rdquo;). A latch circuit is provided which is active when them aster is in low-power mode. The latch circuit watches for the very first negative-going clock pulse (from the slave), and its configuration is such that when latched, it holds the clock line low. Holding the clock line low prompts the slave to discontinue efforts to send the data. Stated differently, the slave will not conclude that it had successfully sent its data, and this prompts the slave to retain a copy of its data for later resending.

Power conservation with a synchronous master-slave serial data bus

A controller contains software which, when triggered in some prearranged way such as assertion of an input to the controller, calculates a digital signature for the contents of the protected memory of the controller. The digital signature is preferably extracted from the contents of the memory by means of a function that varies greatly with even small changes to the memory contents. The function preferably is such that one cannot easily determine from the output what input generated the output. The function is preferably such that one cannot easily create a data set for input that yields any particular predetermined output. The circuitry generating the signature may be embedded in hardware of the controller so that its digital signature function is unknown even to the programmer writing the main body of code to be stored in the protected memory. With such a hardware configuration, it is possible to have a very high degree of confidence that the memory contents are what they are expected to be.

Microcontroller with secure signature extraction

A clock stretching circuit (,) mites between a synchronous bus (,) and a microcontroller (,) which is asleep most of the time to save electrical power. The bus is of a type in which a slow bus device can cause the sender of data to &ldquo;hold&rdquo; the data until the slow device is up to speed. The stretching circuit (,) is of small component count and low power consumption, and there is no requirement for a continuous clock. In one embodiment is comprised of a triple analog switch (,) and a very small number of additional components. In another embodiment a dual four-position multiplexer (,) is employed. In still another embodiment, four transistors (,) are used with handful of additional components. A level shifter (,) including an MOSFET and a large-value resistor help to minimize power drain within the bus device. The components can be external to an off-the-shelf microcontroller or can be included in an IC that also contains an embedded microcontroller.

Clock stretcher and level shifter with small component count and low power consumption

A controller contains software which, when triggered in some prearranged way such as assertion of an input to the controller, calculates a digital signature for the contents of the protected memory of the controller. The digital signature is preferably extracted from the contents of the memory with a function that varies greatly with even small changes to the memory contents. The function preferably is such that one cannot easily determine from the output what input generated the output. The function is preferably such that one cannot easily create a data set for input that yields any particular predetermined output. The circuitry generating the signature may be embedded in hardware of the controller so that its digital signature function is unknown even to the programmer writing the main body of code to be stored in the protected memory. With such a hardware configuration, it is possible to have a very high degree of confidence that the memory contents are what they are expected to be.

Stored program system with protected memory and secure signature

An improved energy-saving keyboard with low parts count accomplishes a sophisticated regime of low-power mode intervals in response to key closures and communications from the computer to which the keyboard is connected. An interrupt pin of the keyboard controller (encoder) prompts the transition from low-power mode to normal mode. The communications from the computer is synchronous communications mediated by a clock line, and the interrupt pin is tied not to the clock line but to the data line of the synchronous channel. The interrupt pin is also tied to a resistor array providing pullup biases to the keyboard matrix; in normal-power mode a discrete output of the encoder forces the common point of the resistor array to a fixed voltage level. In low-power mode, on the other hand, the discrete output is not asserted, and the resistor array is pulled high by a pullup impedance of relatively high resistance to the fixed voltage level. In this way, any key closure at the keyboard triggers the interrupt. LEDs, if lit, are gradually dimmed in the absence of key activity, to conserve electrical power.

Growing community of inventors

New York, NY, United States of America

Ioannis Milios