Abstract: A fuel delivery system for an internal combustion engine that includes an electric-motor fuel pump and an electronic control circuit for applying electrical power to the pump motor from a source of d.c. potential. The electronic control circuit is responsive to voltage level at the source of d.c. potential for automatically boosting electrical power applied to the pump motor when voltage available at the source decreases to a preselected level. In the preferred embodiments, the pump motor is a d.c. motor, and the electronic control circuit takes the form of a d.c.-to-d.c. convertor having a transformer and a rectifier circuit coupling the transformer to the motor. Power switches apply alternating current to the transformer when voltage available at the d.c. power source is inadequate, thereby increasing or boosting power applied to the motor through the rectifier circuit.

Abstract: Sensor and reference wires are directly exposed to the airflow past a vehicle. The wires are electrically conductive, and each has a resistance varying with its temperature. A continuous fixed voltage is passed through the reference wire. A short pulse of greater constant voltage is passed through the sensor wire, the voltage of sufficient magnitude to cause the rapid heating of the sensor wire during the pulse. The resultant rate of heat of the sensor wire, and its final temperature at the end of the pulse, is determined by whether ice or water is on the sensor wire. Circuitry is provided to generate an ice present signal when the difference in current flow during the pulse through the sensor wire and through the reference wire is of such magnitude and sign as to indicate that ice was in contact with the sensor wire. Due to water's heat of fusion, the effect of ice on the sensor wire is readily distinguished from the effect of water.