QTECH QSW-3400 Инструкция по настройке User Manual

Page 465

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464

without affecting other devices. Such a power supply buffer of 10W is designed for

power source protection, and calls for special attention.

The displayed value of Power might over the value of Max. This involves the

relationship between the displayed power and the actual power, for instance:

The power set on the port: A, represents the actual output PoE power

The displayed power: B, represents the total power of the port (total current ? total

voltage)

The power loss set on the port: C, represents power loss of the internal Sensor ohmic

resistance, MosFet etc.

Then: B=A+C

If the power is set as A=500mW, according to the following table, the compensating

current will be I=2.44mA (500mW/50V=10mA assuming the current working voltage is

50V), plus the compensating power C=50V?2.44mA=122mW

B=A+C=500+122=622mW. So, only when the displayed power reaches 622mW, the

PD will be disconnected

Table:

Max Working Current (mA)

Compensating Current (mA)

50

2.44

100

4.88

150

9.76

200

17.08

250

24.41

350

31.73

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