Electric power conversion systems – Current conversion – Including d.c.-a.c.-d.c. converter
Patent
1987-12-11
1989-09-19
Wong, Peter S.
Electric power conversion systems
Current conversion
Including d.c.-a.c.-d.c. converter
363 16, 363 60, 323224, 320 1, 123596, 123605, H02M 3335
Patent
active
048687308
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to DC to DC converter power supply systems.
BACKGROUND OF THE INVENTION AND PRIOR ART
The need for, and actual designs of, DC to DC converters for converting automobile battery voltage to a higher voltage for charging a capacitor of a capacitive discharge ignition system are known in the prior art. These converters generally operate on the principle of switching an inductive current and are thus sensitive to load conditions, are generally not as efficient as desired, and are often more complex than desired.
The provision of "boost power" during the ignition firing period (which consists of several ignition pulses separated by non-pulsing periods) so as to reduce the decay rate of the voltage of the various pulses is disclosed herein by me as a baseline for further improvements disclosed herein.
The present invention comprises a novel form of DC to DC converter power supply which, among other things, uses a capacitor and not an inductor as the storage element, and is load insensitive, is efficient, is simple, and is to able to operate synchronously with the operation of the ignition discharge circuit and thus provide some level of power boost even at moderate power levels.
OBJECTS OF THE INVENTION
It is a principal object of this invention to provide a power supply with a capacitor as tne energy storage element, and which is simple and practical and provides power smoothly to an output load capacitor which may be discharged in a time regular way, the power supply called a "synchronous current pump" when operated in synchronization with said time regular discharge; said current pump made up of a large capacitor, a transformer, an inductor, diodes and switches, and operating as a CD circuit providing "slugs" of current synchronously with the output CD circuit firing. In general, because of the power supply's generally synchronous operation with the load capacitor discharge, it in effect also provides "boost power" or high power during the spark pulsing period to maintain a higher voltage during this period.
Another object is to provide several forms of such current pump including a particular simple form (the simplified current pump) which has only one switch in its input circuit (i.e. the battery-side switch is replaced with a diode and an inductor, if an inductor is not otherwise present).
Another object is to provide an optimized simplified current pump which includes across the transformer secondary winding in parallel with the output load capacitor and diode a small tuning and feedback capacitor whose value is precisely determined by circuit principles to provide optimized current pump timing and positive electrical energy feedback, to provide high output power, very simple and low cost design, and a very high efficiency when the current pump is operated in a timed manner determined by this optimized circuit.
Other features and advantages will be pointed out hereinafter, and will become apparent from the following discussion including a Summary of the invention and Description of Particular Preferred Embodiments of the invention when read in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
This invention comprises a novel DC to DC converter (called a "current pump") used principally for charging a high voltage output capacitor of a capacitive discharge (CD) ignition circuit. The current pump uses a storage capacitor to store the energy, and itself operates on the principle of a CD circuit by using a shunt switch across the storage capacitor and the primary of a transformer to discharge the storage capacitor and charge the output of load capacitor connected to the output of the transformer. If used to provide power boost, then the current pump is preferably operated synchronously with the ignition pulses to provide slugs of energy in between the pulse firings.
The size of the current pump storage capacitor is much less in value to the the "transformed" output capacitor (generally the order of ten times greater than the actu
REFERENCES:
patent: 4017780 (1977-04-01), Cowett, Jr.
patent: 4184197 (1980-01-01), Cuk et al.
patent: 4257087 (1981-03-01), Cuk
patent: 4317068 (1982-02-01), Ward et al.
patent: 4457285 (1984-07-01), Hamai et al.
patent: 4559590 (1985-12-01), Davidson
patent: 4642750 (1987-02-01), Raets
Hexfet Databook published by International Rectifier, 1981, pp. 36-39.
Cohen Jerry
Combustion Electromagnetics Inc.
Wong Peter S.
LandOfFree
DC to DC converter current pump does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with DC to DC converter current pump, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and DC to DC converter current pump will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-373670