Waveform generator producing output current variations as a function of predetermined input and control signal values

Claim 2

A circuit for providing a shaped output signal in response to variations in the magnitude of an input signal comprising: means for providing first, second, and third control signals, said second control signal having a magnitude intermediate the magnitude of said first and third control signals; first signal generating means responsive to the input signal and the control signals for providing a first output signal having a value that varies In response to input signal variations only between first and second predetermined values determined by the values of said first and second control signals; second signal generating means coupled to receive the input signal and said second and third control signals for providing a second output signal having a value that varies in response to input signal variations only between said second predetermined value and a third predetermined value determined by the value of said third control signal; and means for combining the output signals to provide a resultant signal having a shape determined by the values of the control signals and variations of the input signal.

Claim 3

The circuit of claim 1 in which said first signal generating means comprise: conductive path means including a resistor; first and second signal generating transistor means responsive to said first and second control signals respectively for providing a signal differential across said resistor, said differential having a value determined by the values of said first and second control signals and producing an output signal in said conductive path; and input transistor means responsive to the input signal and to said first control signal for applying input signal values having a predetermined relationship with respect to the value of said first control signal to said first signal generating transistor means to thereby vary the signal differential across said resistor.

Claim 4

The circuit of claim 2 in which: said second signal generating means include: second conductive path means including a second resistor; third and fourth signal generating transistor means responsive to said second and third control signals respectively for providing a signal difference across said second resistor determined by the values of said second and third control signals, the value of said signal difference across said second resistor determining the value of said second output signal provided by the second signal generating means; and second input transistor means responsive to the input signal and to said second control signal for applying input signal values having a predetermined relationship with respect to said second control signal to said third signal generating transistor means to vary the signal difference across said second resistor.

Claim 5

The circuit of claim 3 in which: said third control signal has a value greater than said second control signal, said second control signal has a value greater than said third control signal; said input transistor means comprise means for applying only those input signal values greater than said first control signal to said first signal generating transistor means to reduce the signal differential across said resistor; and said second input transistor means comprise means for applying only those input signal values greater than said second control signal to said third signal generating transistor means to reduce the signal difference across said second resistor.

Claim 6

The circuit of claim 4 further including feedback transistor means intermediate the second control signal providing means and said second input transistor means for preventing input signal values applied by said second input transistor means to said third signal generating transistor means from altering the value of the signal difference provided across said first resistor.

Claim 7

The circuit of claim 1 further including: an energy draining subsection connected to said combining means and switchingly connected to said first and second signal generating means for draining energy from said combining means in proportion to the value of signals received from said first and second signal generating means.

Claim 8

A circuit for generating an output waveform varying with the magnitude of an engine operating parameter signal provided by engine operating parameter signaling means, said waveform generating circuit comprising: a. first and second sources of constant referEnce potential; b. first and second waveform generating means each comprising: i. first control voltage generating means comprising first control impedance means and first control voltage coupling means, said first control voltage coupling means being coupled to said first source of constant reference potential and said first control impedance means for cooperating with said first control voltage impedance means to provide a first control voltage; ii. second control voltage generating means comprising second control voltage impedance means coupled to said second source of constant reference potential, second control voltage coupling means coupled to said second control voltage impedance means, and parameter signal coupling means coupled to said second control voltage coupling means and said engine operating parameter signaling means, said parameter signal coupling means operative to couple said engine operating parameter signal to said second control voltage coupling means only when the magnitude of said parameter signal exceeds a first predetermined magnitude, said second control voltage coupling means operative to provide a second control voltage which is a second constant control voltage less than said first constant control voltage only when the magnitude of said engine operating parameter is less than said first predetermined magnitude, which varies between said first and second constant control voltages as the magnitude of said engine operating parameter signal varies between said first predetermined magnitude and a second predetermined magnitude greater than said first predetermined magnitude, and which substantially equals said first control voltage as long as said magnitude of said engine operating parameter exceeds said second predetermined magnitude, said first predetermined magnitude of said first waveform generating means being less than said first predetermined magnitude of said second waveform generating means and said second predetermined magnitude of said first waveform generating means being substantially equal to said first predetermined magnitude of said second waveform generating means, and iii. output impedance means having first and second ends respectively coupled to said first and second control voltage coupling means, said output impedance means cooperating with said first and second control voltage coupling means to provide an output current varying with the difference between said first and second control voltages, said output current varying towards a constant current level only when the magnitude of said operating parameter signal exceeds said first predetermined magnitude and remaining at said constant current level as long as the magnitude of said engine operating parameter signal exceeds said second predetermined magnitude; c. output waveform generating means coupled to each said second control voltage coupling means for combining said output currents of said first and second waveform generating means to provide said output waveform; and d. feedback means coupling said first control voltage coupling means of said first waveform generating means and said second control voltage coupling means of said second waveform generating means for holding said second control voltage of said second waveform generating means substantially equal to said first control voltage of said first waveform generating means when the magnitude of said engine operating parameter is less than said first predetermined magnitude of said first waveform generating means, whereby said output current of said second waveform generating means begins to vary towards said constant current level only after the magnitude of said engine operating parameter signal exceeds said second predetermined magnitude of said first waveform generating means so that said output current of just one of said first and second signal generating means varies when the magnitude of said engine operating parameter varies.

Claim 9

A circuit for generating an output waveform varying with the magnitude of an engine operating parameter signal provided by engine operating parameter signaling means, said waveform generating circuit comprising: a. first and second sources of constant referEnce potential; b. first and second waveform generating means each comprising: i. first control voltage generating means comprising first control impedance means and first control voltage coupling means, said first control voltage coupling means being coupled to said first source of constant reference potential and said first control impedance means for cooperating with said first control voltage impedance means to provide a first control voltage; ii. second control voltage generating means comprising second control voltage impedance means coupled to said second source of constant reference potential, second control voltage coupling means coupled to said second control voltage impedance means, and parameter signal coupling means coupled to said second control voltage coupling means and said engine operating parameter signaling means, said parameter signal coupling means operative to couple said engine operating parameter signal to said second control voltage coupling means only when the magnitude of said parameter signal exceeds a first predetermined magnitude, said second control voltage coupling means operative to provide a second control voltage which is a second constant control voltage less than said first constant control voltage only when the magnitude of said engine operating parameter is less than said first predetermined magnitude, which varies between said first and second constant control voltages as the magnitude of said engine operating parameter signal varies between said first predetermined magnitude and a second predetermined magnitude greater than said first predetermined magnitude, and which substantially equals said first control voltage as long as said magnitude of said engine operating parameter exceeds said second predetermined magnitude, said first predetermined magnitude of said first waveform generating means being less than said first predetermined magnitude of said second waveform generating means and said second predetermined magnitude of said first waveform generating means being substantially equal to said first predetermined magnitude of said second waveform generating means, and iii. output impedance means having first and second ends respectively coupled to said first and second control voltage coupling means, said output impedance means cooperating with said first and second control voltage coupling means to provide an output current varying with the difference between said first and second control voltages, said output current varying towards a constant current level only when the magnitude of said operating parameter signal exceeds said first predetermined magnitude and remaining at said constant current level as long as the magnitude of said engine operating parameter signal exceeds said second predetermined magnitude; c. output waveform generating means coupled to each said second control voltage coupling means for combining said output currents of said first and second waveform generating means to provide said output waveform; and d. feedback means coupling said first control voltage coupling means of said first waveform generating means and said second control voltage coupling means of said second waveform generating means for holding said second control voltage of said second waveform generating means substantially equal to said first control voltage of said first waveform generating means when the magnitude of said engine operating parameter is less than said first predetermined magnitude of said first waveform generating means, whereby said output current of said second waveform generating means begins to vary towards said constant current level only after the magnitude of said engine operating parameter signal exceeds said second predetermined magnitude of said first waveform generating means so that said output current of just one of said first and second signal generating means varies when the magnitude of said engine operating parameter varies.

Claim 10

The circuit of claim 7 wherein at least one of saiD first and second control voltage coupling means comprises a transistor having an electrode coupled to one of said first and second ends of said output impedance means.

Claim 11

The circuit of claim 8 wherein at least one of said parameter signal coupling means and said feedback means comprises a transistor having an electrode coupled to said second control voltage impedance means.

Claim 12

The circuit of claim 9 wherein each of said transistors has a second electrode and has a predetermined voltage drop between said first and second electrodes when conducting, said predetermined voltage drop causing said output current of said first waveform generating means to equal said constant current level at substantially the same magnitude of said engine operating parameter signal as that at which said output current of said second waveform generating means begins to vary towards said constant current level.

Claim 13

The circuit of claim 7 wherein said first and second control voltage coupling means, said feedback means and said parameters signal coupling means each comprise a transistor having first and second electrodes and a predetermined voltage drop therebetween when conducting said predetermined voltage drop causing said output current of said first waveform generating means to equal said constant current level at substantially the same magnitude of said engine operating parameter signal as that at which said output current of said second waveform generating means begins to vary towards said constant current level.