Digital ignition spark timing angle control with read only memory
First Claim
1. An ignition spark timing control system for use with a spark ignition internal combustion engine and a sequence control arrangement comprising:
- a read only memory pre-programmed to produce an output binary signal representation of predetermined ignition spark timing angle based upon the instantaneous value of both of two selected engine operating parameters at each of a plurality of respective selected points within the range of values in response to respective input address signals whereby over the range of values of the two selected engine operating parameters the read only memory generates a three-dimensional surface of ignition spark timing angles based upon the two selected engine parameter values;
means for producing input address signals for said read only memory in response to binary signal representations of instantaneous values of said selected two engine operating parameters;
means for applying said input address signals to said read only memory whereby the binary signal representation of an ignition spark timing angle is produced by said read only memory in response to each of said input address signals; and
means effective to vary the binary signal representations of the ignition spark timing angles as retrieved from said read only memory in accordance with engine manifold vacuum in substantial inverse proportion to atmospheric pressure whereby said three-dimensional surface generated by said read only memory is tilted about a selected engine parameter value as an axis in an amount substantially inversely proportional to actual atmospheric pressure.
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Abstract
A read only memory is pre-programmed to produce an output binary signal representation of a predetermined ignition spark timing angle based upon the instantaneous value of both of two selected engine operating parameters at each of a plurality of respective selected points within the range of values in response to respective input address signals. Over the range of values of the two selected engine operating parameters, therefore, the read only memory generates a three-dimensional surface of ignition spark timing angles. The binary signal representations of the ignition spark timing angles retrieved from the read only memory are varied in accordance with engine manifold vacuum and actual atmospheric pressure to tilt the three-dimensional surface generated by the read only memory about a selected engine parameter value as an axis in an amount substantially inversely proportional to actual atmospheric pressure.
65 Citations
5 Claims
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1. An ignition spark timing control system for use with a spark ignition internal combustion engine and a sequence control arrangement comprising:
- a read only memory pre-programmed to produce an output binary signal representation of predetermined ignition spark timing angle based upon the instantaneous value of both of two selected engine operating parameters at each of a plurality of respective selected points within the range of values in response to respective input address signals whereby over the range of values of the two selected engine operating parameters the read only memory generates a three-dimensional surface of ignition spark timing angles based upon the two selected engine parameter values;
means for producing input address signals for said read only memory in response to binary signal representations of instantaneous values of said selected two engine operating parameters;
means for applying said input address signals to said read only memory whereby the binary signal representation of an ignition spark timing angle is produced by said read only memory in response to each of said input address signals; and
means effective to vary the binary signal representations of the ignition spark timing angles as retrieved from said read only memory in accordance with engine manifold vacuum in substantial inverse proportion to atmospheric pressure whereby said three-dimensional surface generated by said read only memory is tilted about a selected engine parameter value as an axis in an amount substantially inversely proportional to actual atmospheric pressure.
- a read only memory pre-programmed to produce an output binary signal representation of predetermined ignition spark timing angle based upon the instantaneous value of both of two selected engine operating parameters at each of a plurality of respective selected points within the range of values in response to respective input address signals whereby over the range of values of the two selected engine operating parameters the read only memory generates a three-dimensional surface of ignition spark timing angles based upon the two selected engine parameter values;
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2. An ignition spark timing control system for use with a spark ignition internal combustion engine and a sequence control arrangement comprising:
- a read only memory pre-programmed to produce an output binary signal representation of a predetermined ignition spark timing angle based upon the instantaneous value of both engine manifold vacuum and speed at each of a plurality of respective selected points within the range of values in response to respective input address signals whereby over the range of values of engine manifold vacuum and speed the read only memory generates ignition spark timing angles based upon engine manifold vacuum and speed in the form of a three-dimensional surface having engine speed, engine manifold vacuum and timing angles as respective axes;
means for producing input address signals for said read only memory in response to binary signal representations of instantaneous values of engine manifold vacuum and speed;
means for applying said input address signals to said read only memory whereby the binary signal representation of an ignition spark timing angle is produced by said read only memory in response to each of said input address signals;
means for producing an output binary signal representation of a value derived from engine intake manifold vacuum values and atmospheric pressure values, said output binary signal representation value varying inversely with atmospheric pressure; and
means for producing an output binary signal representation of the sum of said binary signal representation of an ignition spark timing angle retrieved from each read only memory and said output binary signal representation of said last named means whereby said three-dimensional surface generated by said read only memory is tilted about the engine speed axis thereof in an amount substantially inversely proportional to atmospheric pressure.
- a read only memory pre-programmed to produce an output binary signal representation of a predetermined ignition spark timing angle based upon the instantaneous value of both engine manifold vacuum and speed at each of a plurality of respective selected points within the range of values in response to respective input address signals whereby over the range of values of engine manifold vacuum and speed the read only memory generates ignition spark timing angles based upon engine manifold vacuum and speed in the form of a three-dimensional surface having engine speed, engine manifold vacuum and timing angles as respective axes;
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3. An ignition spark timing control system for use with a spark ignition internal combustion engine and a sequence control arrangement comprising:
- a read only memory pre-programmed to produce an output binary signal representation of a predetermined ignition spark timing angle based upon the instantaneous value of both of two selected engine operating parameters at each of a plurality of respective selected points within the range of values in response to respective input address signals whereby over the range of values of the two selected engine operating parameters the read only memory generates a three-dimensional surface of ignition spark timing angles based upon the two selected engine parameters values;
means for producing input address signals for said read only memory in response to binary signal representations of instantaneous values of said selected two engine operating parameters;
means for applying said input address signals to said read only memory whereby the binary signal representation of an ignition spark timing angle is produced by said read only memory in response to each of said input address signals;
first means responsive to engine manifold vacuum for producing a binary signal representation of an ignition spark vacuum advance timing angle for each of various values of engine manifold vacuum;
second means responsive to atmospheric pressure for producing a binary signal representation of a percentage of said binary signal representation of ignition spark advance angle produced by said first means as determined by atmospheric pressure, means responsive to said first and second means for producing the binary signal representation of the product of the said binary signal representations produced by said first and second means; and
means responsive to said last means for adding the binary signal representation produced by said last means to the binary signal representation of ignition spark advance angle retrieved from said read only memory for producing a binary signal representation of total ignition spark advance angle.
- a read only memory pre-programmed to produce an output binary signal representation of a predetermined ignition spark timing angle based upon the instantaneous value of both of two selected engine operating parameters at each of a plurality of respective selected points within the range of values in response to respective input address signals whereby over the range of values of the two selected engine operating parameters the read only memory generates a three-dimensional surface of ignition spark timing angles based upon the two selected engine parameters values;
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4. An ignition spark timing control system for use with a spark ignition internal combustion engine and a sequence control arrangement comprising:
- a read only memory pre-programmed to produce an output binary signal representation of a predetermined ignition spark timing angle based upon the instantaneous value of both of two selected engine operating parameters at each of a plurality of respective selected points within the range of values in response to respect input address signals whereby over the range of values of the two selected engine operating parameters the read only memory generates a three-dimensional surface of ignition spark timing angles based upon the two selected engine parameters values;
means for producing input address signals for said read only memory in response to binary signal representations of instantaneous values of said selected two engine operating parameters;
means for applying said input address signals to said read only memory whereby the binary signal representation of an ignition spark timing angle is produced by said read only memory in response to each of said input address signals;
first means responsive to engine manifold vacuum for producing a binary signal representation of an ignition spark vacuum advance timing angle for each value of engine manifold vacuum;
second means responsive to atmospheric pressure for producing an output binary signal representation of a percent value which varies inversely from a maximum to a minimum value with increasing values of atmospheric pressure;
means responsive to said binary signal representations produced by said first and second means for producing the binary signal representation of the product thereof; and
means effective to produce the sum of said binary signal representation of an ignition spark timing angle retrieved from said read only memory and the binary signal representation of the product of the binary signal representations of said first and second means.
- a read only memory pre-programmed to produce an output binary signal representation of a predetermined ignition spark timing angle based upon the instantaneous value of both of two selected engine operating parameters at each of a plurality of respective selected points within the range of values in response to respect input address signals whereby over the range of values of the two selected engine operating parameters the read only memory generates a three-dimensional surface of ignition spark timing angles based upon the two selected engine parameters values;
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5. An ignition spark timing control system for use with a spark ignition combustion engine and a sequence control arrangement comprising:
- a read only memory pre-programmed to produce an output binary signal representation of a predetermined ignition spark timing angle based upon the instantaneous value of both of two selected engine operating parameters at each of a plurality of respective selected points within the range of values in response to respective input address signals whereby over the range of values of the two selected engine operating parameters the read only memory generates a three-dimensional surface of ignition spark timing angles based upon the two selected engine parameters values;
means for producing input address signals for said read only memory in response to binary signal representations of instantaneous values of said selected two engine operating parameters;
means for applying said input address signals to said read only memory whereby the binary signal representation of an ignition spark timing angle is produced by said read only memory in response to each of said input address signals;
first means responsive to engine manifold vacuum for producing an output binary signal representation of an ignition spark vacuum advance timing angle for each value of engine manifold vacuum, second means responsive to atmospheric pressure for producing an output binary signal representation of a percent value which varies inversely from a maximum value at approximately two-thirds normal atmospheric pressure to zero at normal atmospheric pressure;
means for producing an output binary signal representation of the product of the output binary signal representation of said first means multiplied by the output binary signal representation of said second means; and
means for producing an output binary signal representation of the sum of said binary signal representation of an ignition spark timing angle retrieved from said read only memory and the output binary signal representation of said last means.
- a read only memory pre-programmed to produce an output binary signal representation of a predetermined ignition spark timing angle based upon the instantaneous value of both of two selected engine operating parameters at each of a plurality of respective selected points within the range of values in response to respective input address signals whereby over the range of values of the two selected engine operating parameters the read only memory generates a three-dimensional surface of ignition spark timing angles based upon the two selected engine parameters values;
Specification