Abstract: A method of filtering an oxygen sensor signal is provided. The method includes obtaining the oxygen sensor signal from the oxygen sensor on a periodic basis. The oxygen sensor signal is then compared to an average oxygen sensor signal value. If the oxygen sensor signal is greater than the average oxygen sensor signal value, a high signal counter is incremented. If the high signal counter is greater than a high signal count threshold, the oxygen sensor signal is forced to a high signal value. If the oxygen sensor signal is less than the average oxygen sensor signal value, a low signal counter is incremented. If the low signal counter is greater than a low signal count threshold, the oxygen sensor signal is forced to the low signal value. The high and low signal count thresholds correspond to a preselected period of time indicating a low or high signal trend within the oxygen sensor signal.

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 solid state sequence logic circuit comprising a plurality of NOR gates fabricated on a single silicon chip generates an electrical signal whenever a seat belt switch is actuated indicating the utilization of the seat belt before a corresponding seat switch is actuated indicating the presence of an occupant. This logic circuit, while primarily intended for use in any type of vehicle, is applicable to determine whenever a pluraity of events takes place in an order other than a predetermined order.