Abstract: A sampling circuit monitors a high voltage level in an electric vehicle drive. A resistor ladder receives a drive voltage to be sampled and provides sufficient isolation to allow use of low cost switching devices. An N-channel MOSFET is connected between the ladder and a reference resistance. A junction between the source terminal of the MOSFET and the reference resistance provides a sampled voltage output adapted to be input to an analog-to-digital converter. A discrete optocoupler has an output side with a collector and an emitter. The collector is coupled to the resistor ladder, and the emitter is connected to a gate terminal of the MOSFET and coupled to the ground reference by a load resistor.

Abstract: A sampling circuit monitors a high voltage level in an electric vehicle drive. A resistor ladder receives a drive voltage to be sampled and provides sufficient isolation to allow use of low cost switching devices. An N-channel MOSFET is connected between the ladder and a reference resistance. A junction between the source terminal of the MOSFET and the reference resistance provides a sampled voltage output adapted to be input to an analog-to-digital converter. A discrete optocoupler has an output side with a collector and an emitter. The collector is coupled to the resistor ladder, and the emitter is connected to a gate terminal of the MOSFET and coupled to the ground reference by a load resistor.

Abstract: A circuit is provided for detecting peaks of a sinusoidal input signal includes circuitry for generating first and second sinusoidal output signals that are out of phase with one another and with the sinusoidal input signal. A comparator block compares the sinusoidal output signals to determine instances where the amplitudes of the first and second sinusoidal output signals cross over each other. The sinusoidal output signals may lead the sinusoidal input signal somewhat so that, after taking into account processing delay, the indicated crossover instances substantially coincide with peaks in the sinusoidal input signal such that a trigger signal generated by the circuit accurately indicates the timing of the peaks.

Abstract: A circuit is provided for detecting peaks of a sinusoidal input signal includes circuitry for generating first and second sinusoidal output signals that are out of phase with one another and with the sinusoidal input signal. A comparator block compares the sinusoidal output signals to determine instances where the amplitudes of the first and second sinusoidal output signals cross over each other. The sinusoidal output signals may lead the sinusoidal input signal somewhat so that, after taking into account processing delay, the indicated crossover instances substantially coincide with peaks in the sinusoidal input signal such that a trigger signal generated by the circuit accurately indicates the timing of the peaks.

Abstract: A connection system for communicating multiple signals between a steering wheel and a steering column of a vehicle over a single wire is provided that uses time division to multiplex multiple signals. A plurality of signals are multiplexed together ranging from two to as many signals as desired. Input switches are grouped together to form a ladder multiplexer, such as a resistive multiplexer, that includes voltage and current muxing. A plurality of ladder multiplexers are joined together in a time division multiplexing scheme that operates continuously. An analog line may be added as a single channel. A marker pulse is used to signal the start of each time window to be divided for all the channels. Time division multiplexing is provided by a number of switching means.

Abstract: A connection system for communicating multiple signals between a steering wheel and a steering column of a vehicle over a single wire is provided that uses time division to multiplex multiple signals. A plurality of signals are multiplexed together ranging from two to as many signals as desired. Input switches are grouped together to form a ladder multiplexer, such as a resistive multiplexer, that includes voltage and current muxing. A plurality of ladder multiplexers are joined together in a time division multiplexing scheme that operates continuously. An analog line may be added as a single channel. A marker pulse is used to signal the start of each time window to be divided for all the channels. Time division multiplexing is provided by a number of switching means.

Abstract: Dashboard dimmer light circuit for a vehicle, for example a car or truck. A power supply 10 provides a step-function voltage signal to an op-amp oscillator circuit 20 which provides a triangular voltage oscillation signal to an op-amp level comparator 40 which, in turn, compares the triangular voltage oscillation signal to a voltage reference for providing a pulse-width-modulated (PWM) voltage signal to a power FET driver 70 which, in turn, responds to the pulse-width-modulated voltage signal by providing a current signal to an automobile dashboard dimmer light 80. Features of the invention include a) a dashboard dimmer light having a stable oscillator frequency, b) PWM duty cycle stability in a dashboard dimmer light, c) efficient accomplishment of the invention's oscillator and level comparator functions within a single IC, d) reduction of electromagnetic interference which might otherwise intefere with other electronic equipment in the dashboard.

Abstract: A power supply polarity reversal protection device includes a voltage controlled switching device, e.g. an N-channel MOSFET connected between the power supply output (e.g. a positive supply voltage) and the circuit to be powered by the supply, i.e. the load. A diode, preferably the parasitic diode inherent in the MOSFET between the drain and source, is arranged so that when the positive supply terminal is connected to the transistor, the diode is forward biased and will allow a diode current to flow. A sensing means generates a control terminal voltage in response to the diode current flow. This control terminal voltage is applied to the switching means control gate and is sufficient to cause full conduction through the switching means. If, instead, a negative supply voltage is connected to the transistor, the diode will be reverse biased and no current will flow.

Abstract: A DC-to-DC converter is disclosed that uses a relay coil as an inductor. A relay has a coil and an associated relay contact. When the coil is energized, the contact closes and connects a first DC voltage signal to an electrical load. The coil is periodically energized and de-energized. The duration of de-energization is less than that necessary to permit the contact to open. The periodic energization and de-energization of the coil results in voltage values being developed across the coil. A rectifying diode is used to electrically couple the coil to a storage capacitor. The voltage developed across the storage capacitor provides a second DC voltage signal having a value greater than the first DC voltage signal relative to a common reference.

Abstract: An electronic control system for a steering assembly having an electric motor coupled to the steering assembly for providing power assist. The electric power assist motor is drivably connected to a steering member for assisting movement thereof in response to applied input torque to the vehicle steering wheel. The electronic control unit monitors an output signal from a torsion sensor which measures the amount of applied input torque. The electronic control unit generates a pulse width modulated signal having a duty cycle proportional to the measured amount of applied input torque. Solid state switches provide connection between the vehicle battery and the motor, the connection time being controlled by the duty cycle of the pulse width modulated signal. A speed decoder determines which of a plurality of speed ranges the vehicle is moving. A plurality of look-up tables are provided, each table includes a value of power assist for a given amount of applied input torque.

Abstract: An electronic control system for a steering system having an electric motor coupled to the steering system for providing power assist. The steering system is of the rack and pinion type having an input gear coupled to the steering wheel and a pinion gear in meshing engagement with the rack. Two torsion sensors are coupled across the input and pinion gears and generate analog output signals. When no input torque is applied to the steering wheel, the output signals from the two torsion sensors are equal. When input torque is applied to the steering wheel, the signals from the torsion sensors vary substantially linearly in opposite directions. An electronic control unit controls operation of the electric power assist motor in accordance with the output signal from one of the torsion sensors. Failsafe circuitry is provided for monitoring the outputs of the redundant torsion sensors to insure proper control of the electric power assist motor.