US3797471A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Breakerless trigger circuit with variable dwell for ignition systems
Assignee: Motorola Solutions Inc
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Filing: 1972-04-14
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Granted: 1974-03-19
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Expires: 1992-04-14
Abstract
Abstract A triggering circuit for an ignition system to develop electric signals which correspond to the closing and opening of breaker points. A transistor which controls the current flow through the primary winding of a standard ignition coil is in a quiescent off condition when the engine is not being cranked or turning. Only upon cranking of the engine will the transistor be rendered conductive for a period of time, corresponding to the dwell angle of the system, to apply given-width pulses to the primary winding of the ignition coil. The termination of the pulses produces spark voltage at the secondary winding of the ignition coil. Means are provided to automatically increase the dwell angle of the system at a predetermined engine speed.
Inventors
- 👤 G Schuette
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:24
CPC Classifications
F; F02; F02P; F02P3/00; F02P3/02; F02P3/04; F02P3/055; F02P3/0552; F02P3/0556; F02P3/045; F02P3/0453
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
243 words
An ignition triggering circuit for an ignition system of a fuel combustion engine, including in combination: an ignition coil having a primary winding through which pulses of current flow the width of which determine the dwell of the system; a first current control device coupled to said primary winding to apply given-width pulses of current thereto at a given engine speed to cause an ignition spark to occur at the termination of each pulse, said first current control device having a control electrode; sensor means coupled to the engine for producing an electric signal in response to the rotation of the engine; coupling means connected between said sensor means and the control electrode of said first current control device to render said first current control device conducive at one point of said electric signal and to render said first current control device nonconductive at another subsequent point of said electric signal to produce said given-width pulse; and said coupling means including a resistor-capacitor coupling network and a second current control device in parallel with said coupling network, said second current control device being operative to bypass said electric signal therethrough at an engine speed below a predetermined value and to cause said electric signal to pass through said coupling network at an engine speed above said predetermined value to increase the dwell of the system, thereby providing improved fuel igniting properties of the spark produced by the ignition system at the higher speeds.
Claim 2
Dependent Claim
243 words
An ignition triggering circuit for an ignition system of a fuel combustion engine, including in combination: an ignition coil having a primary winding through which pulses of current flow the width of which determine the dwell of the system; a first current control device coupled to said primary winding to apply given-width pulses of current thereto at a given engine speed to cause an ignition spark to occur at the termination of each pulse, said first current control device having a control electrode; sensor means coupled to the engine for producing an electric signal in response to the rotation of the engine; coupling means connected between said sensor means and the control electrode of said first current control device to render said first current control device conducive at one point of said electric signal and to render said first current control device nonconductive at another subsequent point of said electric signal to produce said given-width pulse; and said coupling means including a resistor-capacitor coupling network and a second current control device in parallel with said coupling network, said second current control device being operative to bypass said electric signal therethrough at an engine speed below a predetermined value and to cause said electric signal to pass through said coupling network at an engine speed above said predetermined value to increase the dwell of the system, thereby providing improved fuel igniting properties of the spark produced by the ignition system at the higher speeds.
Claim 3
Dependent Claim
67 words
The ignition triggering circuit of claim 1 further including a disabling transistor connected in circuit with said second current control device and having a base electrode coupled to said sensor means to receive electric signals therefrom to render said second current control device non-conductive to increase the dwell of the system in response to the number of pulses received at said base electrode of said disabling transistor.
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) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |