Reflective ignition timing process

• US 4,106,461 A
• Filed: 02/25/1976
• Issued: 08/15/1978
• Est. Priority Date: 02/25/1976
• Status: Expired due to Term

• Current Assignee: Sebastian Louis Giannini
• Original Assignee: Sebastian Louis Giannini
• Inventors: Giannini, Sebastian Louis
• Primary Examiner(s): Cox, Ronald B.
• Application Number:
  US05/661,288
• Time in Patent Office: 902 Days
• Field of Search: 123/148 E, 123/148 CB, 324/16 T, 250/338, 250/347
• US Class Current: 123/613
• CPC Class Codes: F02P 7/073 Optical pick-up devices

Abstract

The subject of this disclosure is a process through which the timing function is performed for electronic ignition systems. Being specifically proposed for motorcycle use, it is a unique process intended to eliminate the shortcomings of those techniques in present use, namely those employing mechanical points and magnetic pick-ups.

Claims

1. An ignition system for internal combustion engines comprising a light source and photodetector, a shutter rotated at a speed proportional to engine speed to alternately interrupt and pass light from said light source to said photodetector, an indicator actuated by said photodetector to preoperationally align light from said light source to said photodetector, a pulse shaper actuated by said photodetector to provide rapid signal transition between voltage levels resulting from passage and interruption of light from said light source to said photodetector, a pulse amplifier actuated by said pulse shaper to provide switching of current through the ignition coil, said lightsource being a light emitting diode and said photodetector being a phototransistor each integrally mounted and geometrically related whereby light from said light source to said phototransistor has a predetermined focal distance from the said interrupter, said interrupter consisting of a cylindrical sleeve with alternate reflective and light absorbing areas corresponding to the timing requirements of the engine, said pulse shaper being a regenerative comparator with switchable inputs to produce outputs in phase or opposite in phase to input to drive an electronically switched inductive ignition output stage or capacitive discharge ignition output stage to the ignition coil.

2. An ignition system as in claim 1 wherein said indicator is a voltage sensing light emitting diode preceded by a driver amplifier that senses the amount of light from said source to said pickup by detecting said pickup output voltage during the reflective mode of operation.

3. An ignition sytem as in claim 1 wherein said interrupter is the standard breaker cam lobe and said pulse shaper is a regenerative comparator with a voltage reference that is proportional to the pulse width from said photodetectors causing a shift in the triggering point on the cam as a function of engine speed and hence providing an electronic advancing function.

4. An ignition system as in claim 1 wherein said pulse amplifier is a power switching transistor preceded by a power switching Darlington amplifier that transforms the current output capability of said pulse shaper to one capable of driving said switching transistor and hence the ignition coil.