stu@hpficad.HP.COM (Stu Bell) (06/11/88)
>> >>I heard on the radio last night (at about 3 a.m.) that the navy was >>going to do a test on EMP by causing a similar voltage effect out over >>the ocean to see if a ship's communication systems would get zapped. >> >The navy is playing with the unknown.. How can they simulate the EMP caused >by a nuclear explosion with out a nuclear explosion? You get an aircraft carrier, see, and put carpet all over the landing deck. Then serve a big dinner on deck, with Exlax slipped into the food. Afterward you have a big dance, so everybody scuffs their feet a lot and builds up a humongous static charge. When the Exlax takes effect, all 2000 of the crew will reach for the same doorknob at the same time, giving off a huge EMP. Mil STD EMP as per DOC 1492-4423-A. Stu Bell HP Colorado IC Division "Sleep machine? Yeah, that's it in the corner there."
dale@amc-vlsi.UUCP (Dale Wlasitz) (06/14/88)
>>>I heard on the radio last night (at about 3 a.m.) that the navy was >>>going to do a test on EMP by causing a similar voltage effect out over >>>the ocean to see if a ship's communication systems would get zapped. >>> >>The navy is playing with the unknown.. How can they simulate the EMP caused >>by a nuclear explosion with out a nuclear explosion? I am curious about the effects of EMP on electronic systems in general. What can be done to minimize damage to electronic circuitry? What components/subsystems etc. are most susceptable (sp?) to EMP. What are typical pulse durations and peak amplitudes? Obviously smaller scale lab experiments have been conducted. What are the effects on us humans in the same vicinity as the damaged electronics? just curious, Dale disclaimer: contents may settle during shipping
wolfgang@mgm.mit.edu (Wolfgang Rupprecht) (06/16/88)
In article <517@amc-vlsi.UUCP> dale@amc-vlsi.UUCP (Dale Wlasitz) writes: >I am curious about the effects of EMP on electronic systems in >general. What can be done to minimize damage to electronic circuitry? >What components/subsystems etc. are most susceptable (sp?) to EMP. >What are typical pulse durations and peak amplitudes? Obviously smaller >scale lab experiments have been conducted. What are the effects on >us humans in the same vicinity as the damaged electronics? Well, I guess this posting can be a test of sorts. Lets see if our friends at tycho.ARPA are still on usenet... This information comes from "Compliance Engineering 1988" Wellesley Press, Framingham Ma. pages 316-322. The peak voltage of a "typical" (???) EMP wave is 50kV/m with a rise time of ~10 nS (10-8 S) and a fall time of ~1 mS (10-6). The total energy received is only about 0.6 J/m**2. The electric field strength remains fairly constant in the 10khz to 1Mhz band. It decreases by a factor of 100:1 in the 1Mhz to 100Mhz band. It continues to decrease faster for frequencies greater than 100Mhz. Most of the energy is between 100khz and 10Mhz. 99% of the energy is below 100Mhz. Obviously you can shield from this is by 1) having a fairly high integrity ground/shielding system 2) use low-pass filtering 3) use diode clamps to +/- power supplies and user MOV's to clamp those supplies themselves. The EMP simulator mentioned in this article uses HV capacitors discharged through spark gaps. (This is probably only good for a small zap.) Some references from the same article: Bodson, D., "Electromagnetic Pulse and the Radio Amateur," QST August 1986 pg. 15. Elgal Corp., "Systems for EMP Simulation and RFI Material Testing," published by AR, 160 School House Road, Souderton, PA 18964-9990 Goldstein, C. and Tehori A., "A Small Parallel Plate System for EMP Simulation". IEEE EMC Symposium 1987 pg. 135 -- Wolfgang Rupprecht ARPA: wolfgang@mgm.mit.edu (IP 18.82.0.114) TEL: (617) 267-4365 UUCP: mit-eddie!mgm.mit.edu!wolfgang