As far as you are concerned that is your real life. What do you mean by EMI for Real Life? As far as Passing EMI is concerned you have to design your equipment to meet your appropriate standard in the manner dictated by the standard. No EMC literature discusses these real options. How are the common mode chokes working at all? And then what should we connect our Y capacitors to?.there is no Earth. …and what if we just don’t bother connecting our chassis’s (A and B) to earth at all?.after all, the power cord earth connection is NOT a connection at RF…its too high Z. (e)…Two core cable with screen connected to chassis at “B”? (d)…Two core cable with screen connected to chassis at “A”? (c)…Two core cable with screen…screen left floating…it may as well float…both our chassis’s are already floating at RF? (b)…Three core cable with third connector connected to chassis at each end? Take the blue cable between the two enclosures in the attached. I mean, Feedthrough capacitors, etc etc aren’t much use without an RF reference plane. So straight away no official EMC literature is of any help to us!!!ĭoes anyone have an “EMC guide for real-life, cost constrained situations” document, instead of these “perfect EMC” guides which tell how to do EMC for super-expensive medical devices or military devices with RF gasketted connectors etc? I’ve read tons of them and they are no use. So we have no RF reference plane!!!…and our metal chassis is basically floating at RF !!! We have two panels, whose metal enclosure is earthed, but that earth comes from the earth wire in the long 3-core power cord….so that connection is so high Z to RF that its NOT a connection at all. The “canopy” idea is like the attached, but far simpler and cheaper. …What do you say? Surely it must reduce radiated emissions? It cannot posibbly act like an antenna itself since it will be connected to 0V GND of the 10W buck PCB. The top (inductor side) of the 10W DCDC buck faces the enclosure opening, so we wonder if we can actually put a simple shield over the top of the PCB? …as follows….just make a PCB the same size as the 10W Buck PCB (8cm x 3cm), and simply use PCB pillars to mount it above the 10W Buck PCB like a canopy……have this “canopy” PCB simply with a total copper pour over it, and connect this copper pour to the 0V of the 10W Buck PCB. Anyway, we wonder about some shielding directly over the SMPS? Obviously the (screened) cable will likely be responsible for some of this failure, but also the semi-open enclosure we also think acts like an antenna. So when we take it for radiated emissions testing, it fails. As you can see, box B contains a 10W DCDC Buck, but this enclosure B is open at the front.
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