The present invention relates generally to electrostatic discharge protection devices and methods, and more specifically, to a micro tube spark gap type electrostatic discharge protection device and an electrostatic discharge protection method employing a high frequency noncoupled starter circuit.
Heretofore, the assignee of the present invention has developed spark gap devices that function as electrostatic discharge protection devices. These electrostatic protection devices have a voltage versus time characteristic during discharge that is similar to the curve shown in FIG. 1. Referring to
It is desirable to decrease the voltage required for discharge while maintaining the power loss level (or voltage level after saturation), which is the voltage difference between the generally horizontal portion of the curve and zero voltage shown in FIG. 1. However, merely decreasing the gap distance decreases the discharge voltage, and also decreases the energy dissipated during the discharge event, which is generally undesirable. It is also desirable to convert the current pulse to light and heat quickly.
It is an objective of the present invention to provide for a micro tube spark gap type electrostatic discharge protection device having a high frequency noncoupled starter circuit. It is another objective of the present invention to provide for an improved electrostatic discharge protection method.
To accomplish the above and other objectives, the present invention provides for an improved micro tube spark gap type electrostatic discharge protection device that comprises a high frequency noncoupled starter circuit, and an improved electrostatic discharge protection method. The micro tube spark gap type electrostatic discharge protection device comprises first and second spark electrodes that are separated by a spark gap. The high frequency noncoupled starter circuit comprises first and second high voltage electrodes disposed laterally adjacent to the spark gap. The first and second high voltage electrodes are coupled to a high frequency voltage source. The high frequency voltage source generates a high frequency electric field that passes through the spark gap.
The high frequency electric field falls just short of ionizing the gap, but provides additional energy to start the discharge. Once ionization occurs, the high frequency voltage shuts itself off, allowing for maximal energy loss. This results in a voltage versus time characteristic having a decreased ionization voltage and an increased power loss level after the high frequency voltage shuts off.
The various features and advantages of embodiments of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:
Referring again to the drawing figures,
The exemplary micro tube spark gap type electrostatic discharge protection device 10 comprises first and second spark electrodes 11, 12 that are separated by a spark gap 13. The spark electrodes 11, 12 and spark gap 13 are surrounded by a protective housing 14.
The high frequency noncoupled starter circuit 20 comprises first and second high voltage electrodes 21, 22 disposed laterally adjacent to the spark gap 13. The first and second high voltage electrodes 21, 22 are coupled to a high frequency voltage source 23. The high frequency voltage source generates 23 a high frequency electric field that passes through the spark gap 13.
The high frequency voltage supplied by the high frequency voltage source 23 is at a frequency and voltage level that falls just short of ionizing the spark gap 13. However, the high frequency voltage provides additional energy to start a discharge. Subsequent to the occurrence of a discharge event, ionization occurs, and the high frequency voltage supplied by the high frequency voltage source 23 is shut off, allowing for maximal energy loss after ionization.
This results in a voltage versus time characteristic having a decreased ionization voltage and an increased power loss level after the high frequency voltage shuts off.
Referring to
A spark gap 13 comprising first and second separated spark electrodes 11, 12 is provided 31. First and second high voltage electrodes 21, 22 are coupled 32 to a high frequency voltage source 23. The first and second high voltage electrodes 21, 22 are disposed 33 adjacent to the spark gap 13. A high frequency electric field that falls just short of ionizing the spark gap 13 is supplied 34 to the first and second high voltage electrodes 21, 22. An electrostatic discharge occurs 35 across the spark gap 13, causing ionization of the medium (air) in the spark gap 13. Once ionization occurs, the high frequency voltage supplied to the first and second high voltage electrodes 21, 22 is shut off 36, resulting in maximal energy loss after ionization.
Thus, improved apparatus and methods that provide electrostatic discharge protection have been disclosed. It is to be understood that the above-described embodiments are merely illustrative of some of the many specific embodiments that represent applications of the principles of the present invention. Clearly, numerous and other arrangements can be readily devised by those skilled in the art without departing from the scope of the invention.
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Number | Date | Country | |
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20040165326 A1 | Aug 2004 | US |