US3831571A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable dwell ignition system
Assignee: Motorola Solutions Inc
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Filing: 1973-05-11
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Granted: 1974-08-27
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Expires: 1993-05-11
Abstract
Abstract An electronic triggering circuit for an ignition system develops electric signals which correspond to the closing and opening of breaker points to supply variable dwell (ratio of on-to-off) pulses to the primary winding of the ignition coil at speeds below a predetermined RPM. The circuit operates to supply constant dwell pulses to the primary winding of the ingition coil at higher engine speeds.
Inventors
- 👤 H Weber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:50
CPC Classifications
F; F02; F02P; F02P3/00; F02P3/02; F02P3/04; F02P3/045; F02P3/0453
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
377 words
An electronic ignition system for charging and discharging an ignition coil to produce a spark to operate an internal combustion engine, including in combination: Circuit means for conducting direct current through the ignition coil to charge the same in response to a control signal; pulsing means for producing pulses of a predetermined duration at a frequency proportional to engine RPM; coincidence gate means with at least first and second inputs, and an output coupled with said circuit means and producing said control signal on the output thereof upon coincidence of a predetermined relationship of signals on said first and second inputs thereof; constant duty cycle means having an input coupled with said pulsing means and having an output, said duty cycle means responsive to said pulses for producing an output signal on the output thereof indicative of a first state for a predetermined precent of the time interval between the beginning of successive pulses from said pulsing means and indicative of a second state the remainder of said time interval between said pulses, the output of said duty cycle means coupled with the first input of said gate means; time multiplying means operated in response to said pulsing means and said constant duty cycle means, having an input coupled with said pulsing means and further coupled with the output of said duty cycle circuit means, and having an output, said time multiplying circuit means produciNg a gate inhibiting signal on said output, said gate inhibiting signal commencing with the output of said constant duty cycle means changing from an output indicative of said first state to an output indicative of said second state and said inhibiting signal having a variable time period which has a predetermined relationship with the time interval extending from the end of a pulse from said pulsing means until the output signal of said duty cycle circuit means changes from said first state to said second state; and means for coupling the output of said time multiplying means with the second input of said gating means, said gating means producing said control signal upon coincidence of an output indicative of said second state of operation from said constant duty cycle means and termination of said gate inhibiting signal from said time multiplying means.
Claim 2
Dependent Claim
377 words
An electronic ignition system for charging and discharging an ignition coil to produce a spark to operate an internal combustion engine, including in combination: Circuit means for conducting direct current through the ignition coil to charge the same in response to a control signal; pulsing means for producing pulses of a predetermined duration at a frequency proportional to engine RPM; coincidence gate means with at least first and second inputs, and an output coupled with said circuit means and producing said control signal on the output thereof upon coincidence of a predetermined relationship of signals on said first and second inputs thereof; constant duty cycle means having an input coupled with said pulsing means and having an output, said duty cycle means responsive to said pulses for producing an output signal on the output thereof indicative of a first state for a predetermined precent of the time interval between the beginning of successive pulses from said pulsing means and indicative of a second state the remainder of said time interval between said pulses, the output of said duty cycle means coupled with the first input of said gate means; time multiplying means operated in response to said pulsing means and said constant duty cycle means, having an input coupled with said pulsing means and further coupled with the output of said duty cycle circuit means, and having an output, said time multiplying circuit means produciNg a gate inhibiting signal on said output, said gate inhibiting signal commencing with the output of said constant duty cycle means changing from an output indicative of said first state to an output indicative of said second state and said inhibiting signal having a variable time period which has a predetermined relationship with the time interval extending from the end of a pulse from said pulsing means until the output signal of said duty cycle circuit means changes from said first state to said second state; and means for coupling the output of said time multiplying means with the second input of said gating means, said gating means producing said control signal upon coincidence of an output indicative of said second state of operation from said constant duty cycle means and termination of said gate inhibiting signal from said time multiplying means.
Claim 3
Dependent Claim
107 words
The combination according to claim 1 wherein said time multiplying means includes means for causing said variable time period of said gate inhibiting signal to be a predetermined multiple of the time period extending from the end of a pulse from said pulsing means until the output of said duty cycle circuit means changes from an output indicative of said first state to one indicative of said second state, no gate inhibiting signal being produced whenever said pulse from said pulsing means has a duration greater than the duration of an output signal indicative of said first state on the output of said constant duty cycle means.
Claim 4
Dependent Claim
34 words
The combination according to claim 1 wherein said pulsing means includes a monostable multivibrator, the output of which is coupled with the inputs of said constant duty cycle means and said time multiplying means.
Claim 5
Dependent Claim
79 words
The combination according to claim 1 wherein said coincidence gate means has a third input and further including a time interval measuring means coupled with the output of said pulsing means and having an output coupled with the third input of said coincidence gate means, said time interval measuring means normally enabling said coincidence gate means and producing an inhibiting signal on the output thereof in response to a predetermined time interval between successive pulses from said pulsing means.
Claim 6
Dependent Claim
58 words
The combination according to claim 1 further including current limiter means coupled with said circuit means and a third input of said gate means and responsive to current in excess of a predetermined value in said circuit means for applying a signal to the third input of said gate means to effect a change in said control signal.
Claim 7
Dependent Claim
69 words
The combination according to claim 5 further including a time interval measuring means coupled with the output of said pulsing means and having an output coupled with said current limiter means for causing said current limiter means to apply an inhibiting signal to the third input of said gate means to terminate said control signal in response to a predetermined time interval between successive pulses from said pulsing means.
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) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |