National Semiconductor Corporation

Ixys Ch Gmbh

Rex Liebert Allison, Iii

Jeffrey Robert Perry

Wanda Carol Garrett

Martin Garrison

Richard Levin

Phil Gibson

Khang Duy Nguyen

Vandana A Sojrani

John Perzow

Vandana Sojorani

A microcontroller determines the position of the rotor of a brushless, direct-current motor by determining the time of zero crossing of back electromotive force (EMF) emanating from the non-driven phase winding. The zero crossing point is determined by interpolating voltage differentials that are time stamped. Each voltage differential is the difference between the phase voltage of the phase winding and the motor neutral point voltage. The time of zero crossing is determined without using a comparator and without interrupting the processor at each zero crossing point. The processor interpolates the time of zero crossing independently of when the zero crossing point occurs. A hold signal conductor is connected both to a sample and hold circuit and to the load input lead of a time stamp register. The microcontroller simultaneously captures a phase voltage in the sample and hold circuit and a timer count in the time stamp register.

Sample and hold time stamp for sensing zero crossing of back electromotive force in 3-phase brushless DC motors

Sample and hold time stamp for sensing zero crossing of back elecromotive force in 3-phase brushless DC motors

A method and apparatus for thermally simulating a circuit over a network is provided. Techniques are provided for designing a circuit that satisfies user-specified functional requirements received over a network. Based on the specified requirements, components and a topology for constructing the circuit are automatically determined. The components determined during this operation have operational values such that, when the components are arranged according to the topology to form the circuit, the circuit satisfies the user-specified functional requirements. One or more web pages that identify the components are then delivered to the browser over the network. The component and topology information may be used to generate a schematic diagram that is delivered in a web page to the user over the network. The user may thermally simulate the designed circuit. Many characteristics of the board may be adjusted to provide an accurate thermal simulation. The user may place an order over the network for one of the components, a kit of all of the components, a custom made circuit made from the components, and/or a prefabricated circuit that is functionally similar to the one that was designed.

Method to perform thermal simulation of an electronic circuit on a network

Techniques are provided for designing a circuit that satisfies user-specified functional requirements without the user having to obtain additional education or possess specialized software. According to one embodiment, user-specified functional requirements are received over a network from a client executing a browser. The network may be, for example, the Internet. Based on the user-specified requirements, components and a topology for constructing the circuit are automatically determined. The components determined during this operation have operational values such that, when the components are arranged according to the topology to form the circuit, the circuit satisfies the user-specified functional requirements. One or more web pages that identify the components are then delivered to the browser over the network. According to one aspect of the invention, the component and topology information is used to generate a schematic diagram that is delivered in a web page to the user over the network. According to another aspect of the invention, the user is provided with a web page that has a control which, when selected, initiates an operation for placing an order over said network for one of the components, a kit of all of the components, a custom made circuit made from the components, and/or a prefabricated circuit that is functionally similar to the one that was designed.

Network-based integrated device identification and ordering system

A method and apparatus for PCB layout of a circuit simulated over a network is provided. Techniques are provided for designing a circuit that satisfies user-specified functional requirements received over a network. Based on the specified requirements, components and a topology for constructing the circuit are automatically determined. The components determined during this operation have operational values such that, when the components are arranged according to the topology to form the circuit, the circuit satisfies the user-specified functional requirements. The components are placed on a PC board having landing areas designed to accommodate all of the anticipated component sizes for the type of circuit being designed. The PC board may be cropped to the desired size. The PCB may be cropped automatically or manually by the user. The component and topology information may be used to generate a schematic diagram that is delivered in a web page to the user over the network. The user may thermally and electrically simulate the designed circuit. Many characteristics of the PC board may be adjusted to produce an accurate circuit.

Creating a PC board (PCB) layout for a circuit in which the components of the circuit are placed in the determined PCB landing areas

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Santa Clara, CA, United States of America

Rex Liebert Allison, Iii