Assignment

Measure the power consumption of an output device

Device and DC power supply

In order to measure the power consuption about the DC motor we decide to test, we connected it to a DC power supply.

Only few of us knew something about "power supply", so we had some research togedher about it. The first thing was to learn how the DC power supply works. We had to choose the channel and to regulate voltage and current using propers buttons in the machine's right hand side. In this way we setted the potential displacement to 5Volts and the max. current that the device could absorbe to 0.04A (40 mA).

Once we prepared the supply, we connected also the motor to the multimeter in order to measure the current passing through the device, as in this image:

Power consumption

We pressed "OUTPUT" on the DC Power Supply and, looking both at the multimeter and the LED indicator of the power supply, we could have seen the current absorption of our device.


Using the formula

P=V * I

we could find the power dissipation, where V is the Voltage we setted (5V) and I the current we measured (20 mAmp).
Therefore the resulting power consumption of our DC motor was 0,1 Watt.