Means and method for numerically displaying the timing of ignition or other repetitive events

Claim 2

Apparatus for providing numerical display of timing information of the occurrence of an engine event relative to a predetermined angular orientation repeatedly passed in the rotation of a shaft, said apparatus comprising: means for sensing one full revolution of said shaft; means for generating electrical signals at a repetition rate equal to a fixed integral number of cycles per revolution of said shaft; means for controlling the generation of said signals to maintain said integral number at a fixed, known value, said controlling means comprising counting means to count the number of cycles of said signals per revolution, and comparison means to compare the number counted with said integral number and to generate a control signal if said number counted differs from said integral number, said comparison means being connected to said generating means whereby said control signal effects the repetition rate of said signals to maintain said number counted equal to said integral number; means for counting the cycles of said signal for a predetermined interval bounded in time by an occurrence of said event and a passage of said shaft through said predetermined orientation; and means for displaying the count.

Claim 3

The apparatus according to claim 1 comprising means for indicating synchronization of the generated signal frequency with shaft rotation.

Claim 4

The apparatus according to claim 2 in which said indicating means is a light.

Claim 5

The apparatus, according to claim 2 in which said means for indicating synchronization comprises interrupting means connected to said means for displaying said count to permit said count to be displayed only when said signal frequency is synchronized with the shaft rotation.

Claim 6

The apparatus according to claim 1 in which said generating means comprises a voltage-controlled oscillator for providing said signals, said counter comprises a preset counter for counting the output cycles from said oscillator, and said comparison means comprises a switching device activated and deactivated by said sensing means and connected between said oscillator output and said preset counter, and a digital-to-analog converter connected to said preset counter to change the digital output remainder from the preset counter into an analog voltage after deactivation of said switching device, said converter being connected to said oscillator to supply said analog voltage thereto to adjust the frequency of said oscillator.

Claim 7

An apparatus according to claim 5 in which said switching device is a flip-flop gate circuit.

Claim 8

Apparatus for timing and displaying a numerical indication of the phase angle between a pre-determined shaft position of an engine and the position of said shaft at the occurrence of a repetitive engine event, said apparatus comprising first transducer means for generating a first electrical impulse signal once each revolution of said shaft when said shaft is at said pre-determined shaft position; an oscillator for generating a second impulse signal having a frequency that is a known integral multiple of the frequency of said first signal, whereby said shaft rotates a pre-determined angle per cycle of said second impulse; means for controlling said oscillator to hold said second impulse frequency at said integral multiple, said controlling means comprising a presettable counter to compare the number of impulses of said second signal per revolution of said shaft relative to a preset integral number, and means connected to said counter to generate a control signal connected to said oscillator to maintain the frequency thereof at a value such that said number of impulses counted is equal to said preset number; second transducer means for generating a third electrical signal at the occurrence of said repetitive event; a display counter; and gating means connecting said oscillator and said display counter and being connected to said second transducer means to become conductive upon the occurrence of each said third signal to conduct said second electric impulse signal from said oscillator to said display counter during each conductive interval of said gating means, said gating means being connected to said first transducer to become non-conductive upon the occurrence of each said first impulse signal whereby said display counter indicates, in response to the number of pulses of said second impulse signal counted during each conductive interval of said gating means, a numerical measure of the angle through which said shaft rotates between said repetitive event and said pre-determined shaft position.

Claim 9

Apparatus for timing and displaying a numerical indication of the phase angle between a pre-determined shaft position of an engine and the position of said shaft at the occurrence of a repetitive engine event, said apparatus comprising first transducer means for generating a first electrical impulse signal once each revolution of said shaft when said shaft is at said pre-determined shaft position; an oscillator for generating a second impulse signal having a frequency that is a known integral multiple of the frequency of said first signal, whereby said shaft rotates a pre-determined angle per cycle of said second impulse; means for controlling said oscillator to hold said second impulse frequency at said integral multiple, said controlling means comprising a presettable counter to compare the number of impulses of said second signal per revolution of said shaft relative to a preset integral number, and means connected to said counter to generate a control signal connected to said oscillator to maintain the frequency thereof at a value such that said number of impulses counted is equal to said preset number; second transducer means for generating a third electrical signal at the occurrence of said repetitive event; a display counter; and gating means connecting said oscillator and said display counter and being connected to said second transducer means to become conductive upon the occurrence of each said third signal to conduct said second electric impulse signal from said oscillator to said display counter during each conductive interval of said gating means, said gating means being connected to said first transducer to become non-conductive upon the occurrence of each said first impulse signal whereby said display counter indicates, in response to the number of pulses of said second impulse signal counted during each conductive interval of said gating means, a numerical measure of the angle through which said shaft rotates between said repetitive event and said pre-determined shaft position.

Claim 10

The apparatus of claim 7 in which said means for controlling said oscillator comprises a gated control circuit connected to said oscillator to control the frequency thereof and connected to said first transducer means to be turned on and off alternately by successive ones of said first electrical impulse signal.

Claim 11

The apparatus of claim 8 in which said oscillator is a voltage-controlled oscillator.

Claim 12

The apparatus of claim 9 in which said gated control circuit comprises a second gating circuit and said preset counter set at said integral multiple of the frequency of said first signal is connected to said gated control circuit to receive said second impulse signals during complete alternate rotations of said shaft, and said means to generate a control signal comprises a digital-to-analog converter connected to said preset counter to generate an analog voltage corresponding to the count remaining on said preset counter after said second gating circuit has been turned off, said converter being connected to said oscillator to apply said analog voltage thereto to control the frequency of said oscillator.

Claim 13

The apparatus according to claim 10, in which the frequency of said oscillator is a multiple of 360 times the frequency of said first signal.