US3820013A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Internal combustion engine ignition timing instrument
Assignee: Motors Liquidation Co
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Filing: 1972-10-16
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Granted: 1974-06-25
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Expires: 1992-10-16
Abstract
Abstract An operational amplifier circuit is responsive to an ignition signal, produced each time an ignition spark potential is generated for the reference cylinder of the engine, and to the zero crossover point, which occurs at the time the piston of the reference cylinder of the engine is at the top dead center position, of a square wave signal pulse produced by another operational amplifier in response to the single cycle alternating current compression signal output of a rate of change pressure transducer sensitive to the pressure within the reference cylinder for producing a series of timing angle signal pulses, each of a width equal to the period between the ignition signals and the zero crossover point of the square wave signal pulses. These timing angle signal pulses are averaged by a filter circuit network which produces a direct current potential output signal of a magnitude equal to the average of the timing angle signal pulses. This signal is compared with a direct current timing angle reference potential signal by a third operational amplifier which produces an output signal of a magnitude proportional to the number of degrees of the ignition spark advance or retard and a zero output signal when the ignition spark occurs at the selected number of degrees of ignition spark advance.
Inventors
- 👤 W Gaudette
- 👤 P Trimble
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:24
CPC Classifications
F; F02; F02P; F02P17/00; F02P17/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
340 words
An internal combustion engine ignition timing instrument comprising: means for producing an ignition signal each time an ignition spark potential is generated for the reference cylinder of said engine; a rate of change pressure transducer responsive to the pressure within the reference cylinder of said engine for producing a single cycle alternating current compression signal during each compression and power stroke having the zero crossover point occurring when the piston of the reference cylinder of said engine is at the top dead center position; a first operational amplifier having inverting and non-inverting input terminals and an output terminal; means for connecting said inverting input terminal of said first operational amplifier to a point of reference potential; means for applying said alternating current compression signal to said non-inverting input terminal of said first operational amplifier; a second operational amplifier having inverting and non-inverting input terminals and an output terminal; means for connecting said inverting input terminal of said second operational amplifier to a point of reference potential and to said output terminal of said first operational amplifier; means for applying said ignition signal to the said non-inverting input terminal of said second operational amplifier; a third operational amplifier having inverting and non-inverting input terminals and an output terminal; first and second resistors; a capacitor; means for connecting said output terminal of said second operational amplifier to said noninverting input terminal of said third operational amplifier through said first and second resistors in series; means for connecting said capacitor between the junction between said first and second resistors and a point of reference potential; means for producing a direct current timing angle reference potential signal; means for applying said direct current timing angle reference potential signal to said inverting input terminal of said third operational amplifier; and a center scale zero direct current voltmeter responsive to the output signal upon said output terminal of said third operational amplifier for providing an indication of ignition spark advance or retard and a zero reading at the selected number of degrees of ignition spark advance.
Claim 2
Dependent Claim
340 words
An internal combustion engine ignition timing instrument comprising: means for producing an ignition signal each time an ignition spark potential is generated for the reference cylinder of said engine; a rate of change pressure transducer responsive to the pressure within the reference cylinder of said engine for producing a single cycle alternating current compression signal during each compression and power stroke having the zero crossover point occurring when the piston of the reference cylinder of said engine is at the top dead center position; a first operational amplifier having inverting and non-inverting input terminals and an output terminal; means for connecting said inverting input terminal of said first operational amplifier to a point of reference potential; means for applying said alternating current compression signal to said non-inverting input terminal of said first operational amplifier; a second operational amplifier having inverting and non-inverting input terminals and an output terminal; means for connecting said inverting input terminal of said second operational amplifier to a point of reference potential and to said output terminal of said first operational amplifier; means for applying said ignition signal to the said non-inverting input terminal of said second operational amplifier; a third operational amplifier having inverting and non-inverting input terminals and an output terminal; first and second resistors; a capacitor; means for connecting said output terminal of said second operational amplifier to said noninverting input terminal of said third operational amplifier through said first and second resistors in series; means for connecting said capacitor between the junction between said first and second resistors and a point of reference potential; means for producing a direct current timing angle reference potential signal; means for applying said direct current timing angle reference potential signal to said inverting input terminal of said third operational amplifier; and a center scale zero direct current voltmeter responsive to the output signal upon said output terminal of said third operational amplifier for providing an indication of ignition spark advance or retard and a zero reading at the selected number of degrees of ignition spark advance.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |