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Near Field Interference

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Wql

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Hi everyone, just wanna know what is the destination of near field interference?

And how does a resistor placed at the '+' and '-' terminals of a power supply stablised the fluctuation in the voltage and current levels?
 
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jiripolivka

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2. Some regulators in power supplies require a minimum load to operate as designed. Therefore some resistor should be connected to the output terminals. Polarity is irrelevant; the load resistor is needed for the regulator to properly stabilize the output voltage or current.

---------- Post added at 21:02 ---------- Previous post was at 20:56 ----------

1. Near-field interference
Electromagnetic field is radiated from a source like an antenna , gradually forming a plane wave along a line. The close region, "near-field" zone contains several components of elmag.field which create interference and standing waves. If one attempts to detect or evaluate the field intensity distribution, this interference usually masks the expected effects.
One way to correctly measure antenna field is to use an "open range" where the test equipment is located far enough to evaluate the plane wave.
Another way requires to use an anechoic chamber which absorbs the interfering and standing wave fields. The measured field intensity in the near zone must then be mathematically converted in far-field values.
The third way is to radiate not a CW signal but a noise field. As its interference in near-field zone is random, it can be removed by smoothing.
 

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