Abstract: A measurement circuit device for a vehicle includes a power transistor and a voltage measurement circuit coupled to the power transistor that measures a voltage across the power transistor. The measurement circuit device also includes a microcontroller that determines a junction temperature using the measured voltage and adjusts a capacity of the power transistor based on the determined junction temperature. In some embodiments, the measurement circuit device may include a clamping device that clamps the voltage across the transistor when the transistor is off. The measurement circuit device may also include an analog-to-digital converter that converts the measured voltage from an analog value to a digital value.

Abstract: A measurement circuit device for a vehicle includes a power transistor and a voltage measurement circuit coupled to the power transistor that measures a voltage across the power transistor. The measurement circuit device also includes a microcontroller that determines a junction temperature using the measured voltage and adjusts a capacity of the power transistor based on the determined junction temperature. In some embodiments, the measurement circuit device may include a clamping device that clamps the voltage across the transistor when the transistor is off. The measurement circuit device may also include an analog-to-digital converter that converts the measured voltage from an analog value to a digital value.

Abstract: Due to the intermittent nature of electrical connection through moving contacts on electrically propelled vehicles, electrical power converters such as power supplies and inverters are subject to large voltage transients. For compactness and low weight, a high-frequency power converter comprised series-connected high-speed switching circuits, so that an input voltage with voltage transients is split between the switching circuits. As a result, lower-rated switching elements such as IGBT's and MOSFET's can be used while maintaining resistance to input-voltage transients.