Electrical transmission or interconnection systems – Wave form or wave shape determinative or pulse-producing...
Patent
1992-04-28
1995-03-21
Hoff, Marc S.
Electrical transmission or interconnection systems
Wave form or wave shape determinative or pulse-producing...
315180, 315181, 307107, H03K 353
Patent
active
053999100
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a generator of very high voltage, and high current pulses.
2. Description of the Related Art
This invention is used in the supply of very high power klystrons and certain electron tubes, such as free electron lasers. This invention can also be used in the field of flash radiography or ionization. This invention can also constitute a polarization source in accelerators using collectors for recovering the energy of very intense electron beans (from a hundred to a few thousand amperes).
In such applications, the requisite pulses are very high voltage rectangular pulses (above 500 kV), supplied under an impedance of 500 to 3000 ohms and having the shortest possible rise time and the flattest possible amplitude plateau, with a duration of 100 nanoseconds to a few microseconds.
In existing generators, also known as modulators, use is generally made of a low impedance formation line constituted by discreet components (capacitors and inductances). A high voltage thyratron controls the discharge of the line. The operating voltage of the thyratrons does not exceed 60 kV, so that a step-up transformer has to be used. As a result of the necessary electrical insulation associated by increasing the high voltage, said transformer necessarily has significant magnetic leaks, which limits the rise; time of the output pulse. At 500 kV, the rise time is roughly one microsecond, which can only increase with the output voltage.
FR-A-2 638 304 discloses high voltage, pulse generators comprising coaxial cables charged in parallel by a high voltage source and discharged in series across switches. If T is the transit time in a cable with n cables and the charging voltage V, a voltage having an amplitude of nV/2 for duration 2T is obtained.
Although satisfactory in certain respects, these related art generators suffer from disadvantages. For example, their voltage is limited to a few dozen kilovolts and are also limited in current. This is, on the one hand due to the use of switches of the transistor, thyristor (and similar types) and, on the other hand, to the use of resistors positioned between the output line and the earth or ground and which are exposed to the high voltage supplied.
SUMMARY OF THE INVENTION
The object of the present invention is to obviate these disadvantages by proposing a pulse generator able to operate at a very high voltage (several hundred kilovolts) and at a high current, i.e. at a very high power. To this end, the generator according to the invention provides for the use of spark gap switches and load and trigger resistors, which do not encounter see the very high voltage.
The invention specifically relates to an electric pulse generator in accordance with FR-A-2 638 304 and which is characterized in that the switches are spark gap switches having a first electrode connected to the internal conductor of a cable and a second electrode connected to the external conductor of the following cable and a trigger electrode connected to the trigger control circuit, two ballast resistors being provided between the first electrode and the trigger electrode and the second electrode and the trigger electrode and load resistors are provided between the external conductors of the coaxial cables and between the internal conductors of said coaxial cables.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail hereinafter relative to non-limitative embodiments and with reference to the attached drawings, wherein show:
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 A diagram of an embodiment of a generator according to the invention.
FIG. 2 An example of pulses obtained by the generator according to the invention.
FIG. 1 shows a generator having three commercially available coaxial cables C1, C2, C3, each having an external conductor Ce and an internal conductor Ci, three spark gap switches E1, E2, E3, a high voltage source SHT and a trigger circuit CD. The source SHT is connected to the cables by load resis
REFERENCES:
patent: 3141111 (1964-07-01), Godlove
patent: 3749975 (1973-07-01), Walters
patent: 3814503 (1974-06-01), Milam
English Abstract of Selected Articles from Soviet Bloc and Mainland China Series 5: Electronics and Electrical Engineering vol. 144, No. 21 Oct. 1962, Washington, U.S. pp. 41-42; A. I. Pavlovskiy et al.: `Production of rectangular high voltage pulses` voir le document en entier.
IEEE Conference Record of the 1986 Seventeenth Power Modulator Symposium vol. 17, 1986, New York U.S. pp. 207-210; H. Krompholz et al.: `Slow wave line-type pulsers` voir p. 207, colonne de gauche, ligne 9-ligne 15; FIG. 1.
Buzzi Jean-Max
Lamain Henri
Centre National de la Recherche Scientifique
Hoff Marc S.
Krishnan Aditya
LandOfFree
High voltage/current pulse generator using spark gaps does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High voltage/current pulse generator using spark gaps, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High voltage/current pulse generator using spark gaps will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1151199