Learning the difference between power and energy

Power matters in TinyML, and the target we aim for is in the milliwatt (mW) range or below, which means thousands of times more efficient than a traditional desktop machine.

Although there are cases where we might consider using energy harvesting solutions, such as solar panels, those could not always be possible because of cost and physical dimensions.

However, what do we mean by power and energy? Let's discover these terms by giving a basic overview of the fundamental physical quantities governing electronic circuits.

Voltage versus current

Current is what makes an electronic circuit work, which is the flow of electric charges across surface A of a conductor in a given time, as described in the following diagram:

Figure 1.8 – Current is a flow of electric charges across surface A at a given time

The current is defined as follows:

Here, we have the following...