摘要:
A method of detecting a ground fault condition between a direct current power system and the chassis ground of an electric or hybrid-electric vehicle is provided. The method includes sequentially opening and closing a first switch connected between a positive node of the direct current power system and the chassis ground of the vehicle and a second switch connected between a negative node of direct current power system and the chassis ground. The sequential opening and closing of the first and second switches charges and discharges an inherent capacitance present between the metal components of the direct current power system and the chassis. First and second currents are created as the inherent capacitance is charged and discharged. Measurements of the created first and second currents are then used to determine whether a ground fault condition exists between the direct current power system and the vehicle chassis ground.
摘要:
The ring magnet speed and direction sensing scheme according to the present invention addresses many of the shortcomings of the prior art. In accordance with various aspects of the present invention, a pair of bridges placed on the same semiconductor chip are provided for sensing the passing of north/south transition points on a ring magnet. In accordance with an exemplary embodiment, the bridge contains a first group of runners that are perpendicular to a second group of runners. The bridges are placed to cause the signal from one bridge to slightly follow the signal from the other bridge. Placement of the bridges on the same chip enables highly accurate readings.
摘要:
A method is provided for assuring good electrical contact between a power supply and appropriate regions of silicon wafers to assure proper etching during the micromachining of the silicon die locations on the wafer. A plurality of conductors are disposed in the interstices between rows and columns of die locations and each die location that is to be etched is provided with a conductive extension connecting its relevant region with one of the interstice conductors. A preselected number of die locations are dedicated to the purpose of providing conductive pads against which contacts of a power supply can be disposed. The many interconnections between the row interstice conductors and the column interstice conductors assures good electrical distribution across the entire surface of a first side of the wafer.
摘要:
A method of detecting a ground fault condition between a direct current power system and the chassis ground of an electric or hybrid-electric vehicle is provided. The method includes sequentially opening and closing a first switch connected between a positive node of the direct current power system and the chassis ground of the vehicle and a second switch connected between a negative node of direct current power system and the chassis ground. The sequential opening and closing of the first and second switches charges and discharges an inherent capacitance present between the metal components of the direct current power system and the chassis. First and second currents are created as the inherent capacitance is charged and discharged. Measurements of the created first and second currents are then used to determine whether a ground fault condition exists between the direct current power system and the vehicle chassis ground.