Ferrite Beads For The Scb Anti-rf Technology

In this paper, based on the mechanism of RF on EED, we study the RF-reinforcement technology, in which ferrite beads are used to protect SCB initiators. The research topics include the impedance characteristic of ferrite bead, the ignition performance influence of beads connected onto SCBs, the response characteristic and RF sensitivity of SCB initiators with ferrite beads, the performance influence of SCBs under RF energy and so on. The main conclusions are as follows:(1) LCR meter is used to test the impedance characteristic parameter of ferrite bead under different frequencies. The impedance, inductance, resistance versus frequency curves of different types of beads are obtained. At last, the ferrite bead which has small DC resistance, high rated current and little effect to the ignition performance is selected to enhance the RF-resistance capability of SCB.(2) SCB initiators are tested in the RF sensitivity experiment and the experimental frequency is 400MHz. The 50% firing-power of typical SCBs is 12.48W, while the power of low-energy SCBs is only 8.01W. The 100% firing-powers are 17.06W and 9.74W.(3) None of the typical SCB initiatros or low-energy SCBs, which are in series with ferrite beads, ignites under 20W RF energy. It indicates that the reinforcement of ferrite beads can significantly increase the anti-RF ability of SCB.(4) After RF experiment, the firing sensitivity of SCBs in series with ferrite beads is measured. Results show that the firing sensitivity has no significant change.(5) The results of capacitor discharge ignition experiment show that the ignition performance of SCBs connected with ferrite beads do not significantly change after GTEM experiment.The research results show that the anti-RF performance of SCB initiators with ferrite beads is significantly improved and the beads do not affect the normal ignition of SCBs.