iSystem IOM6 ADIO, Руководство пользователя

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5. Power consumption measurements
Picture 2 below explains how the power consumption can be measured with two voltmeters
respectively with two analog inputs in respect to the IOM6 ADIO.
When measuring power it is necessary that both the voltage and the current are measured at
the same time, and that the relationship between these two is taken into account. The ways
the voltage and current are measured have a great influence on the accuracy. The advantage
of power measurement with a shunt resistor method is that it delivers precise measurements,
it allows a quick detection and elimination of faults.
A shunt is a low-value resistor, connected in series to the load. The “current” through the shunt
is measured by measuring the voltage drop on the shunt and the power is then calculated
with formula:
If the target or just part of the electronic, where we want to measure the power along the
application execution, provides already the shunt resistor in series to the load, user can
connect necessary RS+, RS-, AIN and GND signals from the Power Sense connector to the
target using provided clip wires.
Alternatively, iSYSTEM provides Power Probe featuring already a shunt resistor and different
connection possibilities. With this it’s quick and easy measuring power consumption on
electronic circuit (e.g. evaluation board), which gets power over standard jack and external
power supply.