Conclusion
We can’t illustrate EMC requirements of all products in such an introductory essay. Before we end this essay, there are 2 products to be specifically mentioned.
a. Automotive PMDC motors
There are testing standards and limitation specified with EMI and EMS for automotive components in ISO 11452, IEC/CISPR 25 and GB 18655. Radiated emission test is tested with antenna and test receiver at the frequency of 150KHz to 2.5GHz. The upper limit is to be further extended. Testing method at the frequency range of 2.5GHz to 18GHz is under consideration. Conducted emission test is also specified according to different length of the power cord.
b. Hair dryers and heat guns
Such products use grid electricity. The input voltage is divided by the resistive heater wire and rectified. Because
of the diode junction voltage drop and hysteresis effect of the motor inductive laod, the voltage will have wave
distortion, generating a lot of harmonic waves. Therefore customers usually ask for harmonic current test
besides the conducted emission test. Applicable standards are IEC61000-3-2, EN61000-3-2 and GB17625 etc..