System and method for forming and controlling electric arcs

Abstract

A system and method for growing and controlling an electric arc from an electro-magnetic field generator is described. The arc may be formed substantially straight by growing from successively generated electric fields from electro-magnetic generator, such as a waveform-controlled solid state Tesla coil. The growth and direction of the arc may be controlled by forming a low impedance channel created by an area of focused laser light in the path of the growing arc.

Description

This application claims the benefit of U.S. provisional patent application Ser. No. 60/930,221, filed May 15, 2007, the entire contents of which are hereby incorporated by reference into the present disclosure. This application further hereby incorporates by reference U.S. nonprovisional patent application Ser. No. ______, titled “System and Method for Controlling an Electromagnetic Field Generator,” filed May 15, 2008.

FIELD OF THE INVENTION

The present invention relates to a system and method for forming and controlling electrical discharges or arcs from an electro-magnetic field generator.

BACKGROUND OF THE INVENTION

Various types of electro-magnetic field generators capable of forming electrical discharges are known. For example, a type of air core transformer known as a solid-state Tesla coil (SSTC) is capable of forming such electric arcs. A SSTC is a well-known resonant transformer that typically uses an alternating current power source and at least two coils to generate a high-voltage at an electrode where electric arcs may be formed.

Some previous efforts have attempted to control the path of such electric arcs by having the arcs travel down the path of a laser. Such prior efforts have been unsuccessful at least in part because lasers have sufficient power to create an area between the source and the target of low impedance, which is simply too minute in time to be useful. In most cases, any laser strong enough to ionize a sizable path in air would do more damage to a target than an arc.

Also, these previous efforts have attempted to use a high voltage DC source to create these electric arcs, leaving no direct control over the waveform itself because it is a pulse of DC current. Such a short pulse duration period severely limits the time in which an electrical current can be delivered to a target.

This problem can also be seen with the use of TASERS, which use a straight and direct line of low electrical impedance to pulse controlled waveforms of current and voltage to a target for a desired period of time.

SUMMARY OF THE INVENTION

In certain embodiments, the present invention may provide a system for controlling the formation of an electric arc, comprising: an electro-magnetic field generator that generates a first portion of an electric arc having a beginning at a discharge electrode and a second portion of the electric arc having a beginning at an end of the first portion of the electric arc, wherein the first portion and the second portion of the electric arc are substantially straight. The first portion of the electric arc is formed from a first electric field created by the electro-magnetic field generator and the second portion of the electric arc is formed from a second electric field created by the electro-magnetic field generator. The system further comprises a laser source emitting laser light that is focused to create a low impedance path for the electric arc, wherein the low impedance path is formed to grow or change the direction of the electric arc. The second portion of the electric arc has an end at a desired target and the electric arc has a path between the discharge electrode and the desired target that is substantially straight. The system further comprises an alternating current drive system is connected to the electro-magnetic field generator, wherein the alternating current drive system has a saw-tooth waveform output.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and other aspects of embodiments of the present invention are explained in the following description taken in conjunction with the accompanying drawings, wherein like references numerals refer to like components, and wherein:

FIG. 1 illustrates in perspective view a system for forming a typical electric arc from an electro-magnetic field generator; and

FIGS. 2A and 2B illustrate in perspective view a system for forming a substantially straight electric arc from an electro-magnetic field generator in accordance with an embodiment of the present invention.

FIG. 3A shows a graph of voltage output from a standard square alternating current waveform over time.

FIG. 3B shows a graph of increasing voltage output from a sawtooth alternating current waveform over time.

FIG. 4 illustrates in perspective view a system for controlling an electric arc formed by an electro-magnetic field generator in accordance with an embodiment of the present invention

FIG. 5 illustrates in perspective view a system for forming a substantially straight electric arc from a current drive controlled electro-magnetic field generator in accordance with an embodiment of the present invention

The drawings are exemplary, not limiting.

DETAILED DESCRIPTION

Various embodiments of the present invention will now be described in greater detail with reference to the drawings.

As shown in FIG. 1, a solid state alternating current driving system 004 is disclosed with a square waveform output 007 driving primary coil 001, which induces a current into Tesla resonator 002, thus energizing the Tesla coil. Primary coil 001 is on non-conducting form 006 and secondary coil 002 is on non-conductive form 005.

Primary coil 001 and secondary coil 002 together create a SSTC or air-core resonance transformer that, when driven by driving system 004, produces a relatively high voltage at discharge electrode 003 with respect to ground 009. Secondary coil 002 is connected to discharge electrode 003 (not pictured). The voltage potential between discharge electrode 003 and ground 009 creates an electrical field that drops off as 1/r with respect to discharge electrode 003 where r is the distance from discharge electrode 003. This electric field also creates equal voltage potentials as shown in FIG. 1 by equal voltage potential lines 030-036. These voltage potentials, when strong enough, can rip electrons from the nucleus of atoms, creating an arc or plasma formations. Upon energizing the SSTC shown in FIG. 1, arc 070 is created as it passes through voltage potentials 030-036. As illustrated in FIG. 1, arc 070 starts out growing substantially straight in regions denoted by equal voltage potentials 030 and 031, where the electric field generated by SSTC is relatively strong. However, as arc 070 passes into increasing weaker parts of the electric field denoted by equal potential lines 033, 034, 035, and 036, arc 070 is not substantially straight and its path becomes more random. As the outer edge of arc 070 becomes further away from discharge electrode 003 and as arc 070 grows, the voltage potential lines spread as a function of 1/r. Thus, the electric field strength at equal potential lines 035 and 036 are considerably weaker than at equal potential lines 030 and 031.

In accordance with an embodiment of the present invention, FIGS. 2a and 2b disclose an apparatus for forming a substantially straight arc. As will be understood with reference to the following description, FIG. 2A discloses an apparatus for forming a substantially straight arc in an initial stage and FIG. 2B discloses an apparatus for forming a substantially straight arc in a stage subsequent to that shown in FIG. 2A.

With reference to FIG. 2a, a solid state alternating current driving system 004 is disclosed with saw tooth waveform output 008 driving primary coil 001, which induces current into Tesla resonator 002, thus energizing the SSTC. Primary coil 001 is on a non-conducting form 006 and secondary coil 002 is on a non-conductive form 005. Secondary coil 002 is connected to discharge electrode 003 (not pictured). Primary coil 001 and secondary coil 002 together create a SSTC or air core resonance transformer and when driven by driving system 004 a relatively high voltage at discharge electrode 003 with respect to ground 009 is created. This voltage potential between discharge electrode 003 and ground 009 creates an electrical field that drops off as 1/r with respect to discharge electrode 003 where r is the distance away from discharge electrode 003. This electric field creates equal voltage potentials as shown by equal potential line 040-044. One of ordinary skill in the art recognizes that there are not as many equal voltage potential lines in FIG. 2a and FIG. 2b as in FIG. 1 because square waveform output 007 generates higher voltage potential than sawtooth waveform output 008 due to the instantaneous jump in input power due to square waveform 007.

Upon energizing the SSTC shown in FIG. 2a, arc 071 is formed. Initially, arc 071 is small but substantially straight because it is created in an area denoted by equal voltage potentials lines 040, 041, and 042 where the electric field is relatively strong and consistent. The constantly growing input waveform 008 supplies arc 071 with sufficient electric field to sustain plasma formation around arc 071, but does not give arc 071 enough power to grow substantially in physical length, which would result in arc 071 growing into a weaker part of the electric field. Instead, an appropriate amount of power is generated such that arc 071 is maintained until a next electric field peak in Tesla resonator 002 creates a new electric field around arc 071. For a description of the generation of this next electric field, see U.S. patent application Ser. No. ______, filed on May 15, 2008 entitled “System and Method for Controlling an Electromagnetic Field Generator,” the entire disclosure of which is hereby incorporated by reference.

When a new electric field around arc 071 is generated by SSTC, new equal voltage potential lines 050-054 illustrated in FIG. 2b are created around arc 071. As denoted by distance 17 in FIG. 2b, under the new electric field, the arc itself in FIG. 2b acts as discharge electrode 003 from FIG. 2a. This allows another straight arc to be grown off the end of arc 071 from FIG. 2a to create arc 072 as shown in FIG. 2b. As with arc 071 in FIG. 2a, arc 072 is substantially straight because it is grown in the strong part of the electric field. Furthermore, because the portion of arc 072 nearest to discharge electrode 003 created by the forming of arc 071 is substantially straight, it should be clear that the entire length of arc 072 is substantially straight. This straight arc growing process, as seen from the combination of FIG. 2a and FIG. 2b, can be repeated until the resultant arc reaches its desired length and at that point saw-tooth wave output 008 drops back down to zero from its maximum potential. With reference to FIG. 2b, secondary coil 002 is connected to discharge electrode 003 (not pictured).

FIG. 3a shows a graph of the voltage of a square waveform 007 of an alternating voltage output 107 as a function of time for a typical SSTC. As seen in FIG. 3a, the amplitude of the voltage increases to a maximum value within a few AC cycles. Therefore, the result would be an arc that is formed in areas where the electric field generated by a SSTC is inconsistent or weak or both. Under these circumstances, the arc would be created almost instantaneously and would reach its full arc length in just a few cycles. It should be noted that the energy needed to create this arc is high, and therefore a SSTC that generates such waveforms may be pulsing with a duty cycle in the range of from approximately 0.5% to approximately 5%. For example, FIG. 3a may represent a voltage graph associated with an arc formation generated from a SSTC illustrated in FIG. 1.

FIG. 3b illustrates a graph of the voltage of a saw-tooth waveform of an alternating voltage output 108 as a function of time. As shown in FIG. 3b, the amplitude of the voltage slowly increases over time. In fact, the amplitude of the voltage increases to a maximum value after numerous AC cycles. Such a wave may be created by sending a 008 waveform into a SSTC such that more power per unit of time is sent into the Tesla resonator as time passes. For example, FIG. 3b may represent a voltage graph associated with the arc formation from a SSTC illustrated in FIGS. 2a and 2b.

Another embodiment of the present invention is disclosed with reference to FIG. 4. In FIG. 4, laser source 061 emits laser light 068, which is diverged by lens 062 and then converged by lens 063. Secondary coil 002 is connected to discharge electrode 003 (not pictured). After traveling through lens 62 and lens 63, laser light 068 then converges to focal point 065. At focal point 65 is a small and localized area of relatively high electric field where electrons are ripped away from the nucleus of atoms that serves to make a low impedance carrier of electrical current.

It should be appreciated that lens 063 in FIG. 4 can move a distance 160 thus allowing lens 063 to be moved to position 163. By moving lens 063 to position 163 while laser 061 emits laser light 068 results in converging laser light 068 along a substantially straight line between focal point 065 and focal point 067. The area between focal points 65 and 67 forms a low impedance channel 069 of broken down air. One of ordinary skill in the art will understand that different laser and lens arrangements are possible to form low impedance channel 69.

With reference to FIG. 4, it may be seen that arc 073 created by SSTC may then be used in conjunction with low impedance channel 69. In particular, by forming low impedance channel 69 near arc 073, it is possible to correct or change the path of arc 073 or control its path to a desired target.

FIG. 5 discloses another embodiment of the present invention. FIG. 5 illustrates a substantially straight arc 074 formed by a SSTC, such as the SSTC discussed with reference to FIGS. 2a and 2b. In FIG. 5, arc 074 generated by a SSTC grows such that it hits resistive target 015 connected to ground 009. Secondary coil 002 is connected to discharge electrode 003 (not pictured).

In FIG. 5, current drive transformer 014 connected between ground 008 and the 002 Tesla resonator can detect and measure the amount of current flow in real time and can give constant feedback signals via path 016 to driving system 004. Such an arrangement permits the current flowing through current drive transformer 014 to be the same as, or close to, the current traveling through resistive target 015 connected to ground 009. Thus direct and real time current levels through target 015 can be controlled and measured via current drive transformer 014 and driving system 004 disclosed in FIG. 5.

In one example of this embodiment, one may set driving system 004 to shut down for a few cycles if the current rises above a specified value, such as one milliamp, thus creating a less than lethal arc that could be used to provide an electrical shock to a human target. At such time when the target is engaged, pulsed waveforms could be sent to incapacitate the target. Because a high frequency waveform cannot be felt due to neurons that cannot close and open fast enough, a lower frequency pulsing of the waveform controlled by driver 004 would interact with the neurons of the human body, incapacitating the target if needed. Thus, it is possible to send a harmless or painless arc to a human target as a warning. Alternatively, for a more harmful approach, it would be possible to disregard current monitoring input 016 such that driver 004 could be set for maximum beats per seconds to send a more harmful arc to a target for a desired period of time.

Although illustrative embodiments have been shown and described herein in detail, it should be noted and will be appreciated by those skilled in the art that there may be numerous variations and other embodiments that may be equivalent to those explicitly shown and described. For example, the scope of the present invention is not necessarily limited in all cases to execution of the aforementioned steps in the order discussed. Unless otherwise specifically stated, terms and expressions have been used herein as terms of description, not of limitation. Accordingly, the invention is not to be limited by the specific illustrated and described embodiments (or the terms or expressions used to describe them) but only by the scope of claims.

Claims

1. A system for controlling the formation of an electric arc, comprising:

an electro-magnetic field generator that generates a first portion of an electric arc having a beginning at a discharge electrode and a second portion of the electric arc having a beginning at an end of the first portion of the electric arc,

wherein the first portion and the second portion of the electric arc are substantially straight.

2. The system of claim 1, wherein the first portion of the electric arc is formed from a first electric field created by the electro-magnetic field generator and the second portion of the electric arc is formed from a second electric field created by the electro-magnetic field generator.

3. The system of claim 1, further comprising.

a laser source emitting laser light that is focused to create a low impedance path for the electric arc.

4. The system of claim 3, wherein the low impedance path is formed to grow or change the direction of the electric arc.

5. The system of claim 3, wherein the laser light is focused by an optical lens.

6. The system of claim 1, wherein the second portion of the electric arc has an end at a desired target.

7. The system of claim 6, wherein the electric arc has a path between the discharge electrode and the desired target that is substantially straight.

8. The system of claim 6, further comprising:

an alternating current drive system is connected to the electro-magnetic field generator.

9. The system of claim 8, wherein the alternating current drive system has a saw-tooth waveform output.

10. A system for controlling the formation of an electric arc, comprising:

a laser source that emits laser light to create a low impedance channel; and

an electro-magnetic field generator that forms a substantially straight electric arc, a portion of which is located in the low impedance channel.

11. The system of claim 10, wherein the electric arc has a beginning at a discharge electrode and an end at a desired target.

12. The system of claim 10, wherein first or second electric arc portion are formed in a low impedance channel.

13. The system of claim 10, wherein the low impedance channel is formed by focusing the laser light.

14. The system of claim 10, wherein the electro-magnetic field generator is driven by an alternating current drive system having a saw-tooth waveform output.

15. The system of claim 10, wherein the electro-magnetic field generator is a solid state Tesla coil.

16. A method of forming a substantially straight electric arc, comprising the steps of:

generating a first electric field emanating from a discharge electrode;

growing a substantially straight first electric arc portion having a beginning at the discharge electrode;

generating a second electric field emanating from the first electric arc portion; and

growing a substantially straight second electric arc portion having a beginning at an end of the first electric arc portion to form a substantially straight electric arc.

17. The method of claim 16, wherein first or second electric arc portion are formed in a low impedance channel.

18. The method of claim 16, wherein the substantially straight electric arc connects the discharge electrode to a desired target.

19. The method of claim 16, further comprising:

repeating the generating and growing steps to form a third electric arc portion

having a beginning at an end of the second electric arc portion.

20. The method of claim 16, wherein the first electric field is generated by an electro-magnetic field generator that is driven by an alternating current drive system having a saw-tooth waveform output.