Eng. &Tech.Journal, Vol. 33,Part (A), No.6, 2015 https://doi.org/10.30684/etj.33.6A.2 2412-0758/University of Technology-Iraq, Baghdad, Iraq This is an open access article under the CC BY 4.0 license http://creativecommons.org/licenses/by/4.0 A Simple Model of Capacitor Discharge Through a Spark Gap Dr. Bassam Hanna Habib Computer Communication Engineering Dep, Al-Mansour University College/Baghdad. Email: basmy1960@yahoo.com Received on:23/10/2014 & Accepted on:1/6/2015 Abstract A simple computational model is established to simulate a capacitor discharge process through a spark gap. The model constitutes of three intervals, the first one is concerned with charging the capacitor by a D.C. voltage source, where the voltage across the capacitor raises to a certain critical value regarded as the breakdown voltage of the spark gap. The second interval describes the gap breakdown where the resistance of the ionized gas in the gap decreases very sharply as a result of heating the plasma by the electrical current. This interval is denoted as the resistive phase of the discharge. The third interval describes the discharge through the previously heated plasma in the gap; for this interval the plasma resistance is assumed to have a constant value which is considered as the minimum value obtained at the end of the previous interval (the resistive phase interval). The temporal evolution curves obtained from the model exhibit reasonable trends that conform to the physical situation under study. Also, the comparison made with published data shows an acceptable agreement. The model is employed to perform a parametric comparison to examine the rule of the gap parameters on the voltage and current evolution curves. ﻧﻤﻮذج ﻣﺒﺴﻂ ﻟﺘﻔﺮﯾﻎ ﻣﺘﺴﻌﺔ ﺧﻼل ﻓﺠﻮة اﻟﺸﺮارة اﻟﺨﻼﺻﺔ ﺗﻢ اﻧﺸﺎء ﻧﻤﻮذج ﺣﺎﺳﻮﺑﻲ ﻟﻤﺤﺎﻛﺎة ﻋﻤﻠﯿﺔاﻟﺘﻔﺮﯾﻎ اﻟﻜﮭﺮﺑﺎﺋﻲ ﻟﻤﺘﺴﻌﺔ ﺧﻼل ﻓﺠﻮة ﺷﺮارة. ﯾﺘﻀﻤﻦ اﻟﻨﻤﻮذج ﺛﻼث ﻓﺘﺮات زﻣﻨﯿﺔ، اﻟﻔﺘﺮة اﻷوﻟﻰ ﺧﺎﺻﺔ ﺑﺸﺤﻦ اﻟﻤﺘﺴﻌﺔ ﺑﻮاﺳﻄﺔ ﻣﺼﺪر ﻟﻠﻔﻮﻟﺘﯿﺔ اﻟﻤﺴﺘﻤﺮة، ﺣﯿﺚ ﺗﺮﺗﻔﻊ ﻗﯿﻤﺔ اﻟﻔﻮﻟﺘﯿﺔ ﻋﻠﻰ طﺮﻓﻲ اﻟﻤﺘﺴﻌﺔ ﻟﺤﯿﻦ ﺑﻠﻮغ ﻗﯿﻤﺔ ﺣﺮﺟﺔ ﺗﻤﺜﻞ ﻗﯿﻤﺔ ﻓﻮﻟﺘﯿﺔ اﻷﻧﮭﯿﺎر اﻟﻜﮭﺮﺑﺎﺋﻲ ﻟﻔﺠﻮة اﻟﺸﺮارة. ﺑﯿﻨﻤﺎ ﯾﺘﻢ ﺧﻼل اﻟﻔﺘﺮة اﻟﺜﺎﻧﯿﺔ ﺗﻮﺻﯿﻒ ﻋﻤﻠﯿﺔ اﻷﻧﮭﯿﺎر اﻟﻜﮭ ﺮﺑﺎﺋﻲ ﻟﻔﺠﻮة اﻟﺸﺮارة، ﺣﯿﺚ ﺗﻀﻤﺤﻞ اﻟﻤﻘﺎوﻣﺔ اﻟﻜﮭﺮﺑﺎﺋﯿﺔ ﻟﻠﻐﺎز اﻟﻤﺘﺄﯾﻦ ﻓﻲ اﻟﻔﺠﻮة ﺑﺸﻜﻞ ﺣﺎد ﻧﺘﯿﺠﺔ ﻟﺘﺴﺨﯿﻦ اﻟﺒﻼزﻣﺎ ﺑﺎﻟﺘﯿﺎر اﻟﻜﮭﺮﺑﺎﺋﻲ، وﯾﻄﻠﻖ ﻋﻠﻰ ھﺬه اﻟﻔﺘﺮة ﺑﺎﻟﻄﻮر اﻟﻤﻘﺎوم ﻟﻠﺘﻔﺮﯾﻎ اﻟﻜﮭﺮﺑﺎﺋﻲ. أﻣﺎ اﻟﻔﺘﺮة اﻟﺜﺎﻟﺜﺔ ﻓﺘﻤﺜﻞ ﻋﻤﻠﯿﺔ اﺳﺘﻤﺮار اﻟﺘﻔﺮﯾﻎ اﻟﻜﮭﺮﺑﺎﺋﻲ ﺧﻼل ﺑﻼزﻣﺎ اﻟﻔﺠﻮة ﺑﻌﺪ ﺗﺴﺨﯿﻨﮭﺎ ﺧﻼل اﻟﻔﺘﺮة اﻟﺴﺎﺑﻘﺔ، ﺣﯿﺚ ﯾﺘﻢ ھﻨﺎ ﻓﺘﺮة) اﻓﺘﺮاض ان ﻣﻘﺎوﻣﺔ اﻟﺒﻼزﻣﺎ ﺛﺎﺑﺘﺔ ﺧﻼل ھﺬه اﻟﻔﺘﺮة، وھﻲ ﻣﺴﺎوﯾﺔ ﻟﻠﻘﯿﻤﺔ اﻟﺪﻧﯿﺎ ﻟﻠﻤﻘﺎوﻣﺔ ﻋﻨﺪ ﻧﮭﺎﯾﺔ اﻟﻔﺘﺮة اﻟﺴﺎﺑﻘﺔ .( اﻟﻄﻮر اﻟﻤﻘﺎوم اظﮭﺮت اﻟﻤﻨﺤﻨﯿﺎت اﻟﺒﯿﺎﻧﯿﺔ اﻟﻤﺴﺘﺨﻠﺼﺔ ﻣﻦ ھﺬا اﻟﻨﻤﻮذج، واﻟﻤﺘﻌﻠﻘﺔ ﺑﺎﻟﺘﻐﯿﺮ اﻟﺰﻣﻨﻲ ﻟ ﻠﺘﯿﺎر واﻟﻔﻮﻟﺘﯿﺔ، ﻣﻨﺤﻰ ﻣﻨﻄﻘﻲ ﯾﺘﻮاﻓﻖ ﻣﻊ اﻟﻮاﻗﻊ اﻟﻔﯿﺰﯾﺎﺋﻲ ﺗﺤﺖ اﻟﺪراﺳﺔ. ﻛﻤﺎ ﺑﯿﻨﺖ اﻟﻤﻘﺎرﻧﺔ اﻟﺘﻲ ﺗﻢ اﺟﺮاؤھﺎ ﻣﻊ ﺑﯿﺎﻧﺎت ﻣﻨﺸﻮرة ﺗﻮاﻓﻘﺎ ﻣﻘﺒﻮﻻ. ﺗﻢ اﺳﺘﺨﺪام اﻟﻨﻤﻮذج ﻷﺟﺮاء ﻣﻘﺎرﻧﺔ ﻟﺒﯿﺎن ﺗﺄﺛﯿﺮ ﻣﻌﺎﻣﻼت اﻟﺸﺮارة ﻋﻠﻰ ﻣﻨﺤﻨﯿﺎت اﻟﺘﻐﯿﺮات اﻟﺰﻣﻨﯿﺔ ﻟﻜﻞ ﻣﻦ اﻟﻔﻮﻟﺘﯿﺔ واﻟﺘﯿﺎر.