Electronic radio frequency ignition
US 2876270 A
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March 3, 1959 R. LUTZ ELECTRONIC RADIO FREQUENCY IGNITION Filed Dec. 21. 1953 INVENTOR. QUESELL LJ. LLJTZ I TTORNEY United States Patent ELECTRONIC RADIO FREQUENCY IGNITION Russell L. Lutz, Mohnton, Pa.
Application December 21, 1953, Serial No. 399,549
2 Claims. (Cl. 123-148) This invention relates to an electronic, radio frequency ignition system which is useful for automobiles, trucks, busses and the like, powered by gasoline or similar fuel, and more particularly pertains to a system for increasing the power and miles per gallon obtainable from such fuel so as to provide amazing improvement in performance as well as economy.
In the present day distributor and coil ignition system, the breaker opens and the condenser discharges in the coils primary winding, setting up just one very short pulse for each explosion stroke of the piston. The engine works satisfactorily until the compression is increased such as in pulling up a hard grade. Then, however, the piston must travel downwardly mostly in one hard, instant thrust which causes engine ping, also known as secondary emission. When such high compression exists, gasoline does not continue toburn, or burn completely, because the ignition or burning at the spark plug lasts for a very short instant of time and the flame goes out quicker at higher compressions thus leaving an unburned mixture in the chamber.
Gasoline manufacturers have endeavored to overcome this disadvantage by putting lead solutions in gasoline to avoid this too quick burning at the ignition point of the explosion stroke. However, I find in my experiments that this greatly reduces the after ignition burning time, but does greatly retard engine ping.
After experimenting with vibrator coils which generate about 80% radio frequency currents (and 20% very low alternating current approximating direct current) as distinguished from presently used coils which generate less than 60% radio frequency currents, with the balance low alternating current on high compression engines,I found the gasoline mileage to be increased by approximately 18%, but the disadvantage is that the car has to be driven at not more than 25 M. P. H., as these vibrators vibrate at too slow a place for high speed engines. But from this experiment I found that the engine could be pulled down to M. P. H. on a grade where normally the car had to be shifted at 12 to M. P. H. The result was very smooth power.
I further found that non leaded or white gas would not ping with these vibrator coils which produce this high rate of radio frequency. I further experimented with kerosene and found that it works with such coils, and even starts with a cold engine, whereas it will not work with modern ignition coilsf However the motor develops very little power and smells like a Diesel engine.
To prove that pure radio frequency was needed and that low alternating current, or at least no direct current dare be used, I made up a unit using filtered direct current and timed it to an engine. This engine ran, could not be idled and gave a terrific ping by just raising the throttle mildly.
These experiments proved the necessity for a pure radio frequency spark that should fire from the pistons top explosion stroke to the bottom in a high compression engine, in order to burn the complete mixture.
2,876,270 Patented Mar. 3, 1959 I made a radio frequency generator using an oscillator driver, and final output tube but this was very unsatisfactory because it required all tuned circuits, even to the spark plug, and a slight voltage variation would upset it, but worse still, the spark plug acted as a capacitor and greatly changed its capacity as the compression varied, thus no longer providing a tuned circuit.
Then I provided a multi-vibrator and flyback transformer which is a tuned circuit which produces pulses similar to the old vibrator coils, but instead of 5 to 20 pulses per stroke, this produces pulses per second which can be seen on an oscilloscope. No engine can turn fast enough to out-run the high speed pulses of the generator of this type of ignition. If it could centrifugal force would not permit it.
Referring more particularly to the circuit diagram shown in Figure 1 the unit at the left, surrounded by dotted lines and generally denoted by numeral 1 is a power supply unit having, for convenience, plug-in cables separated from each other. Power supply unit 1 has in its lead-in a fuse F, then feeding a common vibrator VlB which produces through transformer 3s primary winding alternating current stepped up in the secondary winding to an overall 550 volts. This, in turn, is rectified by tube 4 which may be a type 0Z4 tube 275 volt direct current passing through a parasitic resistance 5 then entering capacitor 6, a filter, large in capacity in order to store energy for the timing intervals needed in the generator and timer unit denoted generally by numeral 2. Also in this unit there must be provided a negative bias. of volts for timing which is obtained from one of the plates of tube 4 passing through dropping resistance 7 to a selenium rectifier 8 of low current filtered by capacitor 9, and on to unit 2. Capacitor 10 is merely a line filter.
In the generator and timer unit 2 a multi-vibrator circuit is made up of two tubes 12 and 13, which may be 3A5 type tubes, the two triode units of each envelope being paralleled in order to produce better power output to swing the grid of power output tube 14, which may be type 2E24, being the power output to the high voltage transformer 15.
In operation of this unit, a sawtooth .wave form is needed, since by this there is a gradual build up, then a sharp cut off which produces the fly back needed for transformer 15. These pulses are at the rate of 15,500 kc. per second since the multi-vibrator inductance coil 16 and transformer 15 are tuned.
When voltage is applied to the plates of tubes 12 and 13, current passes through the series circuit of coil 16 and resistor 18, dropping the voltage slightly on the plate of tube 12 thus leaving capacitor 19 in the grid circuit slightly higher in potential. By this time tube 13has caused a similar drop in plate voltage through resistor 20 and capacitor 21. Capacitor 21 is built up by tube 13 as an amplifier to approximately 150 volt peak pulses through capacitor 23 on through resistor 24 which is a parasitic resistance which retards flyback action through capacitor 23 caused by the high voltage of tube 14. Resistor 25 is a grid bias resistance for tube 12. The combination of series resistors 26 and 27 is the grid bias control of tube 13 which is tuned by variable resistor 27 to match the inductance of transformer 15 in turn giving the best spark on the plug.
20 is a dropping resistance for the plate of tube 13; resistor 26a is a series dropping resistance used for these two tubes 12 and 13 since the operating voltage of automobiles is usually 6 or 12 volts, and these tubes are only It will be noticed that the firing or timing is done by negative bias toa cut ofi-point-of tube'14 by means of shorting points 40 located in the cars distributor, unlike the operation of the present day ignition system where the firing takes place .when the points open. These points at their closing time short out a;low current of negative voltage to zero at the point of resistors "29 and 28thus having 150 volts negative across resistor 28 and .zero at the grid of tube 14 and the tube is now amplifying pulses to-transformer 15. When the points open, a negative voltage is again impressed on the grid of tube.14 through resistors 27 and 28.
'In the use of this system I converted the present day distributor 30 with a cap whereby I made a brass ring for the carbon brush 39 to slide on commutators 38 to get the firing at the timethe points 40 close instead of open. I turned the whole distributor accordingly. The high voltage fiyback transformer 15 is such as used in television sets. A suitable transformer is one known in the trade as a.Meritt coil because of its compact design as this transformer 15 and capacitors 31 and 32 must be in a shielded case 33 which slips over the plug and grounds itself. This grounding must be done for two reasons, (1) because all units labeled one per cylinder, must have like capacities since this is somewhat of a tuned circuit, and (2) because of it is not grounded, this unit will interfere with television operation.
31 'is a by-pass condenser in the return direct current line. 32 is a blocking condenser for the direct current passed through tube 13 to the plate of tube 14. As explained hereinbefore direct current causes engine ping. Only pure radio frequency is wanted at the plug and condenser 32 does just this.
In earlier experiments in place of condenser 32 I used a spark gap. This works all right with thesli ght reduction of radio frequency due to the fact that a too wide gap was needed to block direct current.
Another important part which can greatly be improved is the insulation of spark plugs. Some of the better brands on the market will not work on radio frequency since the porcelains used absorb and short .it out before getting to the arcing points.
The plugs can also be made of a good grade of mica as an insulator. This worked best.
To make the present device adaptable to all cars on the market, there are three types of wiring harnesses needed which combines the unit 2 to the distributor and spark plug cylinder units. There ,is one for the 6 cylinder and 8 cylinder straight engines, and one for the V-8 models. This would make it possible to use the present unit on all older as well as new cars.
The following tables indicate suitable circuit constants useful in the present circuit, although these values may be changed somewhat without affecting the operation.
Resistor Ohms Watts Capacitor Mid. Voltage 10, 000 34 005 2, 000 100 1 9 10. 450 470K t- 80. 460 3500 10 1 200 33K 19 002 600 100K 1 22 000250 600 68K 21 0 600 100 23 000680 600 33K 31 00:1 600 221; 1(1) 32 005 20, 000
in miles per gallon, but there was considerable increase in smoothness in running an'd'in idling, as well as a substantial increase in power. The unit was even applied to a car having a high compression ratio of approximately 10 to l, at which ratio engineers use menthol injection in order to burn the mixture and to avoid engine ping. I, found that my ignition system could also be applied to modern high compression engines, such as the present day V-8 engines and that .it would idle much more smoothly and increase the power as well as increase the mileage up to 20 miles per gallon as compared to 12 or 13 miles per gallonnormally obtainable without my ignition system. Moreover, in view of the use of 3A5 miniature tubes, the present unit is very small and compact. Transistors may also be substituted for such tubes to prevent the need of replacement. The present unit is extremely flexible. For operation in cold weather, when the starter pedal is depressed anddrops the battery voltage, Ihave found the secondary voltage can drift from 300 volts to even as low .as volts and remain stable enough to start. While the upper limit of speed has not been determined, 1 have found that half-throttle on a level road produces better than 65 M. P. H.
The various wave forms at different parts of the circuit are shown .in the drawing. It will be noted that radio frequency pulses across the spark plug gaps may be of the order of 1000 pulses per cylinder stroke, depending upon the speed of the engine. That is, the time the distributor breaker points 40 remain closed will determine the length of time that firing takes place. The radio frequency wave, however, remains the same. A spark plug gap of .018 inch gives very good results for normal compressions, but for engines of high compression the gaps may be as low as .01 inch. Thus sustained firing by discharge of a large number of radio frequency pulses across the spark plug gaps after the compression stroke insures complete burning of the fuel therefore greatly increasing the power and efficiency of the engine. The shielding provided by case 33 and the use of a fly-back transformer are very essential features for best operation and stability of the circuit.
Thus, It will be seen that I have provided an efficient, compact and easily installed electronic radio ignition system for providing a radio frequency spark across the spark plug gaps of a gasoline engine-driven motor, which spark is controllable in duration so it may continue during the entire descent of the piston, particularly when under high compression, to insure complete burning of the gasoline mixture in the cylinder and thus prevent ping and loss of power which normally accompanies incomplete combustion; furthermore, I have provided a system which will greatly increase the power, smoothness in idling and running, as well as greatly increase the mileage per gallon obtainable by at least 50 percent and on all modern high compression engines, both the 6 cylinder and 8 cylinder (straight and V-8) types.
While I have illustrated and described an embodiment of my invention, it will be understood that this is by way of illustration only, and that various changes and modifications may be made Within the contemplation of my invention and within the scope of the following claims.
1. In an automotive system including a plurality of spark plugs, a multi-vibrator, direct current power source, a saw tooth generating circuit energized thereby, a timer including a distributor, a fiyback tranformer in series with said distributor, connected in the output of said saw tooth generating circuit for each engine cylinder, a condenser in series with said fiyback transformer and with the central terminal of the corresponding spark plug to prevent passage of D. C. to the spark plug, and a metallic,
, non-magnetic shield enclosing each of said respective flyback transformer, condenser and spark plug assemblies to prevent stray emission of radio frequency currents, whereby pure radio frequency pulses are applied across the gaps of the spark plugs to increase the duration of the spark and the obtainable mileage per gallon of gasoline.
2. In an automobile ignition system including a plurality of spark plugs mounted on an engine cylinder head; in combination, a power unit including a vibrator for generating positive and negative voltages, a generator and timer unit energized thereby, including a distributor, and having an output tube Which develops a saw-tooth Wave form, a plurality of fly-back transformers, each including a winding connected, at one end, to said distributor, and connected, at the other end, to a condenser in series with the central terminal of one of said spark plugs, a plurality of non-magnetic, metallic shields directly mounted on said engine cylinder head, one shield surrounding each spark plug and associated condenser and winding, to prevent emission of stray radio frequency currents, said distributor including a rotating brush and commutator for successively energizing said spark plugs with radio frequency pulses of the order of 15,500 kc. per second, a negative bias being applied to said output tube of said generator and timer unit and to said distributor such that closing of the distributor breaker points short circuits said negative bias to Zero voltage to make said output tube conducting and cause said fiy-back transformers to discharge a series of radio frequency pulses across their associated spark plugs during the entire time said distributor points remain closed and which discharged pulses are interrupted upon Opening of said distributor points.
References Cited in the file of this patent UNITED STATES PATENTS 2,169,818 Scott Aug. 15, 1939 2,408,881 Rettenmeyer Oct. 8, 1946 2,415,138 Kasarjian Feb. 4, 1947 2,461,168 Mcllvane Feb. 8, 1949 2,467,725 Berkey Apr. 19, 1949 2,552,212 Peroutky May 8, 1951 2,606,951 Bychinsky Aug. 12, 1952 FOREIGN PATENTS 509,801 Belgium Oct. 31, 1952