National Instruments cFP-CTR-500, Руководство по эксплуатации, Страница: 7 / 23

© National Instruments Corp. 7 FP-CTR-500 and cFP-CTR-500
The [c]FP-CTR-500 output channels are optically isolated from
the rest of the FieldPoint bank and have short-circuit protection
circuitry. In the ON state, a transistor is turned on between the
positive external supply voltage (V and V
SUP
) and the output
(V
OUT
). In the OFF state, this transistor is turned off, allowing only
a small leakage current to flow. Ensure that the load on any channel
does not draw more than 1 A.
Caution For a cFP-CTR-500 operating in the 50 – 60 °C
temperature range, the output current must not exceed
0.75 A on any channel.
In the ON state, the effective resistance between the output (V
OUT
)
and the supply voltage (V and V
SUP
) is 0.3
Ω
. This resistance
causes a voltage drop between the external supply voltage and the
output voltage. Table 2 lists the actual output voltages based on the
voltage provided by the external power supply.
If the external power supply you are using does not provide one of
the voltages in Table 2, use the following equation to calculate the
actual voltage output.
ActualOutput = V
ext
– ( I
flow
× 0.3 Ω)
where ActualOutput is the voltage sourced by V
OUT
V
ext
is the voltage provided by the external power supply
I
flow
is the current flow through the V
OUT
terminal
Table 2. [c]FP-CTR-500 Output Voltages for a 0.5 A Current Flow
V
V
OUT
10 9.85
12 11.85
24 23.85
30 29.85