Computer based engine analyzer with hardware cylinder counter

Claim 2

An engine test apparatus for use in testing of a multi-cylinder internal combustion engine, the apparatus comprising: cylinder clock means for deriving a cylinder clock signal representative of sequential operation of each cylinder of the engine, the cylinder clock signal exhibiting a predetermined signal transition for each cylinder; a presettable digital cylinder counter for counting down from an initial count (J) to zero in response to the predetermined signal transitions of the cylinder clock signal, the cylinder counter having output terminals for providing a digital cylinder count (Q) which is decremented with each predetermined signal transition, and input terminals for receiving the initial count (J) which is representative of the number of cylinders of the engine; means for producing a signal when the digital cylinder count (Q) reaches zero; reset means for resetting the cylinder counter to the initial count (J) at the input terminals in response to the signal provided when the digital cylinder count (Q) reaches zero; electrical test means for selectively deriving, from the engine, electrical signals indicative of operation of a system or component of the internal combustion engine; operator input means for providing operator input signals indicative of a selected test to be performed; display means for displaying visually a test result of the selected test performed; and digital computer means for controlling operation of the electrical test means as a function of the operator input signals and the digital cylinder count (Q) and for controlling the display means as a function of the electrical signals from the electrical test means, the digital computer means providing the initial count (J) to the input terminals of the presettable digital cylinder counter.

Claim 3

The engine test apparatus of claim 1 wherein the digital computer means monitors the digital cylinder count (Q) and determines a current cylinder number CYL NUM=J-Q+1.

Claim 4

The engine test apparatus of claim 1 and further comprising: cylinder comparator means for comparing the digital cylinder count Q of the cylinder counter with a comparator count (N) and providing a comparator output signal when the digital cylinder count (Q) attains the comparator count (N); wherein the electrical test means selectively derives the electrical signals at a time based upon occurrence of the comparator output signal; and wherein the digital computer means provides the comparator count (N) to the cylinder comparator means.

Claim 5

The engine test apparatus of claim 1 and further comprising: means for providing a No. 1 pulse signal indicative of firing of a No. 1 cylinder of the engine; and wherein the reset means resets the cylinder counter to the initial count (J) in response to the No. 1 pulse signal.

Claim 6

The engine test apparatus of claim 1 and further comprising: operator-controlled means for providing a disable signal to the cylinder counter to inhibit the cylinder counter from counting down in response to the cylinder clock signal.

Claim 7

An engine test apparatus for use in testing of a multi-cylinder internal combustion engine, the apparatus comprising: cylinder clock means for deriving a cylinder clock signal representative of sequential operation of each cylinder of the engine, the cylinder clock signal exhibiting a predetermined signal transition for each cylinder; a presettable digital cylinder counter for counting down in response to the predetermined signal transitions of the cylinder clock signal, the cylinder counter having output terminals for providing a digital cylinder count (Q) which is decremented with each predetermined signal transition, and input terminals for receiving an initial count (J) which is representative of the number of cylinders of the engine, and an output terminal which produces a first signal when the digital cylinder count (Q) reaches a cylinder predetermined digital count; reset means for resetting the cylinder counter to the initial count (J) at the input terminals in response to the first signal; means for comparing the digital cylinder count (Q) with a comparator count (N) and providing a second signal when the digital cylinder count (Q) attains the comparator count (N); electrical test means for selectively deriving, from the engine, electrical signals indicative of operation of a system or component of the internal combustion engine based upon occurrence of the second signal; operator input means for providing operator input signals indicative of a selected test to be performed; display means for displaying visually a test result of the selected test performed; means for controlling operation of the electrical test means as a function of the operator input signals; means for controlling the display means as a function of the electrical signals from the electrical test means; means for providing the initial count (J) to the input terminals of the cylinder counter; and means for providing the comparator count (N).

Claim 8

An engine test apparatus for use in testing of a multi-cylinder internal combustion engine, the apparatus comprising: cylinder clock means for deriving a cylinder clock signal representative of sequential operation of each cylinder of the engine, the cylinder clock signal exhibiting a predetermined signal transition for each cylinder; a presettable digital cylinder counter for counting down in response to the predetermined signal transitions of the cylinder clock signal, the cylinder counter having output terminals for providing a digital cylinder count (Q) which is decremented with each predetermined signal transition, and input terminals for receiving an initial count (J) which is representative of the number of cylinders of the engine, and an output terminal which produces a first signal when the digital cylinder count (Q) reaches a cylinder predetermined digital count; reset means for resetting the cylinder counter to the initial count (J) at the input terminals in response to the first signal; means for comparing the digital cylinder count (Q) with a comparator count (N) and providing a second signal when the digital cylinder count (Q) attains the comparator count (N); electrical test means for selectively deriving, from the engine, electrical signals indicative of operation of a system or component of the internal combustion engine based upon occurrence of the second signal; operator input means for providing operator input signals indicative of a selected test to be performed; display means for displaying visually a test result of the selected test performed; means for controlling operation of the electrical test means as a function of the operator input signals; means for controlling the display means as a function of the electrical signals from the electrical test means; means for providing the initial count (J) to the input terminals of the cylinder counter; and means for providing the comparator count (N).

Claim 9

An engine test apparatus for use in testing of a multi-cylinder internal combustion engine, the apparatus comprising: cylinder clock means for deriving a cylinder clock signal representative of sequential operation of each cylinder of the engine, the cylinder clock signal exhibiting a predetermined signal transition for each cylinder; a presettable digital cylinder counter for counting down from an initial count (J) to zero in response to the predetermined signal transitions of the cylinder clock signal, the cylinder counter having output terminals for providing a digital cylinder count (Q) which is decremented with each predetermined signal transition, and input terminals for receiving the initial count (J) which is representative of the number of cylinders of the engine; means for providing a No. 1 pulse signal indicative of firing of a No. 1 cylinder of the engine; reset means for resetting the cylinder counter to the initial count (J) at the input terminals in response to the No. 1 pulse signal; electrical test means for selectively deriving, from the engine, electrical signals indicative of operation of a system or component of the internal combustion engine; operator input means for providing operator input signals indicative of a selected test to be performed; display means for displaying visually a test result of the selected test performed; and digital computer means for controlling operation of the electrical test means as a function of the operator input signals and the digital cylinder count (Q) and for controlling the display means as a function of the electrical signals from the electrical test means, the digital computer means providing the initial count (J) to the input terminals of the presettable digital cylinder counter.

Claim 10

An engine test apparatus for use in testing of a multi-cylinder internal combustion engine, the apparatus comprising: cylinder clock means for deriving a cylinder clock signal representative of sequential operation of each cylinder of the engine, the cylinder clock signal exhibiting a predetermined signal transition for each cylinder; a presettable digital cylinder counter for counting down from an initial count (J) to zero in response to the predetermined signal transitions of the cylinder clock signal, the cylinder counter having output terminals for providing a digital cylinder count (Q) which is decremented with each predetermined signal transition, and input terminals for receiving the initial count (J) which is representative of the number of cylinders of the engine; means for providing a No. 1 pulse signal indicative of firing of a No. 1 cylinder of the engine; reset means for resetting the cylinder counter to the initial count (J) at the input terminals in response to the No. 1 pulse signal; electrical test means for selectively deriving, from the engine, electrical signals indicative of operation of a system or component of the internal combustion engine; operator input means for providing operator input signals indicative of a selected test to be performed; display means for displaying visually a test result of the selected test performed; and digital computer means for controlling operation of the electrical test means as a function of the operator input signals and the digital cylinder count (Q) and for controlling the display means as a function of the electrical signals from the electrical test means, the digital computer means providing the initial count (J) to the input terminals of the presettable digital cylinder counter.

Claim 11

The engine test apparatus of claim 7 wherein the digital computer means monitors the digital cylinder count (Q) and determines a current cylinder number CYL NUM=J-Q+1.

Claim 12

The engine test apparatus of claim 7 and further comprising: cylinder comparator means for comparing the digital cylinder count Q of the cylinder counter with a comparator count (N) and providing a comparator output signal when the digital cylinder count (Q) attains the comparator count (N); wherein the electrical test means selectively derives the electrical signals at a time based upon occurrence of the comparator output signal; and wherein the digital computer means provides the comparator count (N) to the cylinder comparator means.