recomendations on books that cover EMC theory - Page 1
Forum section: electronics / beginners

author: Simon
author_rank: Unknown
timestamp: February 10, 2019, 06:26:13 pm
content: So i know about:https://www.amazon.co.uk/Electromagnetic-Compatibility-Engineering-Henry-Ott/dp/0470189304and it's too expensive and seems to be more practical than theoretical. I am looking for a companion to the usual shittiness of my HNC course material which usually confuses everything with alternative material being essential in order to understand what they are on about.So far i have read through capacitive and inductive coupling and both subjects seem to have been put through the usual contortions of teeside universities attempt at writing their own version of the subject instead of just recomending a book.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 10, 2019, 08:07:06 pm
content: I mean, you can always find a copy of it online somewhere...There's also a few by Tim Williams (no relation) which are good, dunno about price in comparison.Tim

author: coppice
author_rank: Super Contributor
timestamp: February 10, 2019, 08:13:44 pm
content: The theory side of EMC is just EM theory, so you don't really get theory books on the topic. You get practical books about how EM theory applies to the EMC problems.

author: Simon
author_rank: Unknown
timestamp: February 10, 2019, 08:14:32 pm
content: Well actually I do have a copy and like i say I don't think it goes into much theoretical depth which is what the right up says as it is a practical book. Lets face it when we design PCB's and cabling we don't start trying to apply formulas to stray capacitance's etc we just take the measures and this is described in the book. My course is at the moment along theoretical lines, that particular book would be good for work and I have already told them they should buy a copy.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 10, 2019, 08:41:21 pm
content: I apply formulas for stray capacitances etc....Typically simple things like transmission line equivalent L and C, comparing impedances, that sort of thing. I doubt I'll ever find a place to use an integral in layout as such, though I have done a few in nearby fields (thermal conduction).E&M field problems normally have way too many boundary conditions, so that if you cannot fit it into an already solved case (e.g., microstrip), it's somewhere between ridiculous to impossible to solve analytically (i.e., on paper), and you need a simulator.The two examples that I have integrated, are: the temperature distribution along an evenly heated bar cooled from one end, and a finite panel of some radius, with an isothermal source of some radius in the middle, and uniform cooling capacity over the surface of the panel.The first case is easy: it's a separable differential equation, and the solution is a parabola, with the vertex at the far (uncooled) end of the bar, and the steepest side at the cooled end (which makes sense: the temperature drop across any given segment of the bar is the total power hanging off that end, which is linear with position, so the temperature distribution is quadratic with position).The second case is hard, but in an easy sort of way. The double dependency of heat flow with temperature, in a circularly symmetrical system, leads to a differential equation with solutions of the Bessel functions. IIRC, it was the first half-cycle of the normal Bessel function, with the origin in the center, and the first zero being the periphery of the disk. The shape of this function is oscillatory, but in an unpredictable way (the zeroes are irregular), not quite like a sine wave. This makes sense, as around the origin, there's not much surface area to remove heat, so the temperature remains high; the fact that the heat is spreading out over ever-greater circumferences means the thermal conductivity is good (except for in the very center, where you can imagine a pinpoint source might get very hot indeed, so it's important to have a wide heat-spreading area). As you go out in radius, eventually the area becomes considerable, and temperature starts falling off, and eventually it reaches ambient at infinity, or some nonzero value at the edge of a finite disk. This gives a length scale where most of the heat is dissipated, and diminishing returns are had for larger panels. The diameter of the hot spot is given by the lateral heat spreading (thermal conductivity) of the panel and the heat dissipation rate (the air flow, as it were).Plugging in typical values for, say, a copper clad PCB in still air, we get a radius of 2-4cm and, for typical semiconductors and ambient temperatures, a power dissipation capability of about 5W.Tim

author: Simon
author_rank: Unknown
timestamp: February 10, 2019, 08:49:47 pm
content: well so far my course has talked of capacitive coupling between cables with and without shields (coax or not) and mutual inductance of wires using equivalent circuits. Maybe I just need to read it a couple of times to get it.

author: LukeW
author_rank: Frequent Contributor
timestamp: February 10, 2019, 09:55:00 pm
content: EMC theory? Sure.https://www.amazon.com/Classical-Electrodynamics-third-Text-Only/dp/B004VXJ4KO/ref=mp_s_a_1_3?Seriously though, the Henry Ott book is good. Expensive sure, but thick technical books always are and I would rather have a *good* $100 book than a crap $100 book, and there are plenty of the latter.You could get it from a university library and see if you like it?

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: February 10, 2019, 10:29:31 pm
content: In German there is "Georg Durcansky - EMV-gerechtes Gerätedesign" ISBN-13: 978-3772353864For someone like me - who is not an EE - I find it very accessible. However, I could not find an English translation.Maybe "Tim Williams - EMC for Product Designers" could be what you are looking for. Seems like it is also written from a practical stand point as the Ducansky book.Here is alink to a PDF version of the third edition(2000).Fifth edition (2016) is current - though my guess is, that the updates mainly deal with changes in legislation.Kind regards,FrederikEdit: Tim Williams has been mentioned before by T3sl4co1l, so this is kind of a redundant post. Well...