The DC Power Supply should be selected as follows:
Rs (Internal Resistance) < 0.01 OHM DC
Zs (Internal Impedance) = Rs for frequencies < 400 Hz.
▶ does not deviate more than 1 V from 0 to maximum load (including inrush current)
▶ recovers 63% of its maximum excursion within 100 ms
Vr (Superimposed Ripple Voltage):
▶ does not exceed 0.2 V peak-to-peak
▶ maximum frequency of 400 Hz
☞ When a battery is used for EMC testing, a charging source is needed to achieve the specified voltage reference levels.
☞ It is important to ensure that the charging source does not affect the test.
☞ Linear Power Supplies are preferable vs Switching Power Supplies.
☞ Prior to CISPR 25 test methods ensure that the RF noise produced by the power supply is at least 6 dB lower than the limits specified in EMC Test Plan.
☞ If the Power Supply is located outside of the EMC test chamber, ensure thzt a bulkhead RF filter is used to prevent RF noise from entering or leaving the shielded enclosure.
☞ If using a HV battery, then it must be contained in a shielded enclosure.
☞ 12V Power Supply Volatge = 13.5 (+0.5/-1.0)V
☞ 24V Power Supply Voltage = 26 (+1.0/-2.0 V