US3729647A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spark ignition systems
Assignee: Individual
•
Filing: 1971-05-10
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Granted: 1973-04-24
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Expires: 1991-05-10
Abstract
Abstract A spark ignition system for an internal combustion engine has a capacitor which is charged by an alternator through a rectifier. The capacitor is discharged at intervals to produce a spark, and voltage sensitive means is provided for short-circuiting the alternator output when a capacitor is charged to a predetermined level. Preferably the capacitor discharges through a thyristor, and means is provided for ensuring that the thyristor always turns off between cycles.
Inventors
- 👤 D Mainprize
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:11
CPC Classifications
F; F02; F02P; F02P7/00; F02P7/06; F02P7/067; F02P1/00; F02P1/08; F02P1/086; F02P3/00; F02P3/06; F02P3/08; F02P3/0876; F02P3/0884
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
174 words
A spark ignition system for an internal combustion engine, comprising in combination an alternator driven by the engine, a rectifier having input terminals and output terminals, means coupling said alternator to said input terminals, a capacitor, means coupling said capacitor to the output terminals of said rectifier, whereby said alternator charges said capacitor, voltage sensitive means connected across said capacitor and conducting at a predetermined capacitor voltage, means whereby said voltage sensitive means serves when conductive to shortcircuit the alternator output, and means for discharging the capacitor at intervals to produce a spark, said means for discharging the capacitor including a thyristor connected in a series circuit across said capacitor, said series circuit including the primary winding of an ignition coil, the system further including engine-driven means for turning on said thyristor when a spark is required to discharge the capacitor through said primary winding, and said series circuit further including a pair of oppositely connected diodes in parallel, said oppositely connected diodes assisting in turn-off of said thyristor when the capacitor has discharged.
Claim 2
Dependent Claim
174 words
A spark ignition system for an internal combustion engine, comprising in combination an alternator driven by the engine, a rectifier having input terminals and output terminals, means coupling said alternator to said input terminals, a capacitor, means coupling said capacitor to the output terminals of said rectifier, whereby said alternator charges said capacitor, voltage sensitive means connected across said capacitor and conducting at a predetermined capacitor voltage, means whereby said voltage sensitive means serves when conductive to shortcircuit the alternator output, and means for discharging the capacitor at intervals to produce a spark, said means for discharging the capacitor including a thyristor connected in a series circuit across said capacitor, said series circuit including the primary winding of an ignition coil, the system further including engine-driven means for turning on said thyristor when a spark is required to discharge the capacitor through said primary winding, and said series circuit further including a pair of oppositely connected diodes in parallel, said oppositely connected diodes assisting in turn-off of said thyristor when the capacitor has discharged.
Claim 3
Dependent Claim
38 words
A system as claimed in claim 1 in which the voltage sensitive means comprises a second thyristor connected across the rectified alternator output, and means for turning the thyristor on when the capacitor voltage reaches the predetermined level.
Claim 4
Dependent Claim
21 words
A system as claimed in claim 2 in which said means for turning the second thyristor on is a neon tube.
Claim 5
Dependent Claim
21 words
A system as claimed in claim 2 in which said means for turning the second thyristor on is a Zener diode.
Claim 6
Dependent Claim
22 words
A system as claimed in claim 1 including a diode connected across said primary winding to prevent reverse charging of the capacitor.
Claim 7
Dependent Claim
44 words
A system as claimed in claim 1 including a diode positioned in said series circuit in the cathode path of the first-mentioned thyristor, and a resistor coupling the junction of the first thyristor and diode to the capacitor to reverse bias the first thyristor.
Claim 8
Dependent Claim
16 words
A system as claimed in claim 1 in which the rectifier is a half wave rectifier.
Claim 9
Dependent Claim
16 words
A system as claimed in claim 1 in which the rectifier is a full wave rectifier.
Claim 10
Dependent Claim
16 words
A system as claimed in claim 8 including a Zener diode between the rectifier and capacitor.
Claim 11
Dependent Claim
43 words
A system as claimed in claim 9 including a further capacitor connected across the Zener diode which is connected between the rectifier and first-mentioned capacitor, said further capacitor being coupled to the gate of the first thyristor to reverse bias the said gate.
Claim 12
Dependent Claim
136 words
A spark ignition system for an internal combustion engine, comprising in combination an alternator driven by the engine, a full wave rectifier having input terminals and output terminals, means coupling said alternator to the input terminals of the full wave rectifier, a circuit coupling the capacitor to the output terminals of the full wave rectifier, said circuit including a Zener diode, a thyristor connected in a circuit across said capacitor, said thyristor when conductive serving to discharge the capacitor, means operable upon discharge of said capacitor through the thyristor for producing a spark, and engine-driven means for turning on said thyristor when a spark is required, said Zener diode blocking the circuit from the rectifier to the capacitor for a portion of each cycle of the alternator output so as to facilitate turn-off of the thyristor.
Claim 13
Dependent Claim
136 words
A spark ignition system for an internal combustion engine, comprising in combination an alternator driven by the engine, a full wave rectifier having input terminals and output terminals, means coupling said alternator to the input terminals of the full wave rectifier, a circuit coupling the capacitor to the output terminals of the full wave rectifier, said circuit including a Zener diode, a thyristor connected in a circuit across said capacitor, said thyristor when conductive serving to discharge the capacitor, means operable upon discharge of said capacitor through the thyristor for producing a spark, and engine-driven means for turning on said thyristor when a spark is required, said Zener diode blocking the circuit from the rectifier to the capacitor for a portion of each cycle of the alternator output so as to facilitate turn-off of the thyristor.
Claim 14
Dependent Claim
33 words
A system as claimed in claim 11 including a capacitor connected acRoss the Zener diode and connected through a resistor to the gate of the thyristor so as to reverse bias said gate.
Claim 15
Dependent Claim
91 words
A spark ignition system for an internal combustion engine, comprising in combination an alternator driven by the engine, a half wave rectifier having input terminals and output terminals, means coupling said alternator to the input terminals of said rectifier, means coupling the capacitor to the output terminals of said rectifier, a thyristor connected in a circuit across said capacitor, whereby conduction of said thyristor discharges said capacitor, means operable upon discharge of said capacitor for producing a spark, and engine-driven means for turning on the thyristor when a spark is required.
Claim 16
Dependent Claim
91 words
A spark ignition system for an internal combustion engine, comprising in combination an alternator driven by the engine, a half wave rectifier having input terminals and output terminals, means coupling said alternator to the input terminals of said rectifier, means coupling the capacitor to the output terminals of said rectifier, a thyristor connected in a circuit across said capacitor, whereby conduction of said thyristor discharges said capacitor, means operable upon discharge of said capacitor for producing a spark, and engine-driven means for turning on the thyristor when a spark is required.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-23 | 1976-10-23 | 1977-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-23 | 1980-10-23 | 1981-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-23 | 1984-10-23 | 1985-04-24 | $7700.00 | Window Closed / Lapsed |