Abstract: A mass fluid flow sensor is disclosed which utilizes a sensing bridge circuit to develop a sense (control) signal related to fluid flow. A fluid temperature variable resistor, separate from said bridge circuit, is utilized to implement temperature compensation so that a desired output signal is a function of sensed fluid flow, but is less dependent on fluid temperature than the sense (control) signal provided by the bridge circuit. A resistor in the bridge circuit is selected such that the sense (control) signal provided by the bridge circuit has a rate of change as a function of flow rate substantially independent of fluid temperature, but this sense signal still varies as a function of fluid temperature. This permits fluid temperature compensation of the bridge sense signal in a noncomplex and cost effective manner. An improved adjustable circuit (36-41) is provided for producing a desired temperature variable output signal (V.sub.os).

Abstract: A mass fluid flow sensor is disclosed which utilizes a sensing bridge circuit to develop a sense (control) signal related to fluid flow. A fluid temperature variable resistor, separate from said bridge circuit, is utilized to implement temperature compensation so that a desired output signal is a function of sensed fluid flow, but is less dependent on fluid temperature than the sense (control) signal provided by the bridge circuit. A resistor in the bridge circuit is selected such that the sense (control) signal provided by the bridge circuit has a rate of change as a function of flow rate substantially independent of fluid temperature, but this sense signal still varies as a function of fluid temperature. This permits fluid temperature compensation of the bridge sense signal in a noncomplex and cost effective manner.

Abstract: A digital-analog fuel injection system wherein fuel lean out is controlled by a fuel mapping circuit 36 which provides one of sixteen levels of percent lean out control of the fuel pulse width supplied to an injector. In order to provide an immediate update of the engine demands, a pulse generation circuit 72 operates in real time. The fuel mapping circuit 36 provides corrections to the pulse generating circuit on a sampled update basis. This is accomplished by using a digital word 34 generated by a microprocessor 10 to control a multiplying digital to analog converter whose reference input is an electrical signal (V.sub.MAP) representing the present manifold pressure and an offset voltage (V.sub.O) accounting for the several variable of the system such as the engine, injectors and pressure sensor. The output signal (V.sub.B) from the fuel mapping circuit 34 is then applied to a pulse generating circuit 72 to control the generation of fuel pulse width which is being applied to a fuel injector driver 46 (FIG.

Abstract: A quadrature trigger system for a sequential fuel injection system utilizes a single lobe timing cam connected to the camshaft of a four cylinder internal combustion engine as illustrated in FIG. 2. Positioned in a sensing relationship to the cam are two proximity sensors which generate bilevel electrical signals having a fifty percent duty cycle and which are spaced ninety electrical degrees apart. These electrical signals are decoded in a logic network to direct fuel injection pulses from either of two pulse generators to the proper sequenced fuel injector.