VIPR: Measure voltage, current, power, and resistance of a variable load

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Introduction: Use NI myDAQ to measure and display the characteristics of a variable resistive load: voltage (V), current (I), power (P), and resistance (R). This application is useful for maximum power transfer experiments in linear circuits:

The connection diagram on the front panel shows the complete variable load connected between terminals A and B. The myDAQ analog inputs measure the load voltage and the voltage across a shunt resistance, providing V and I as primary measurements (I is the measured shunt resistor voltage divided by the enterered shunt resistance value). Power is calculated as the product of V and I and load resistance is calculated as V divided by I. The load resistance display is convenient because the value of the variable resistance (potentiometer) can be varied without need for a separate ohmmeter measurement. The optional noise filter can improve the displayed value for power.