Previously I wrote up why the 9V battery sucks. As I thought more about that post, I realized, I never explained how much energy is in a 9 V battery versus say a couple of AA batteries.

For this post, I am going to break down the energy stored in a 9 V battery, the small rectangular kind and compare it to what you get with 6 AA batteries. Yes, it takes up a little more space, but you might be surprised by the difference.

Starting with this new AddOhms TutorialCast series, we are taking a look at Electronics Basics.  The first topic is on the differences between Voltage, Current, and Power. The twist on this explanation is that we are not using the usual “electricity is like water” analogy engineers seem to love.  Instead, we just use plain language to explain the difference between these concepts.

There are many options for powering an Arduino board.  The designers did a great job of designing an auto-select circuit that makes it simple to power the boards.  However, there are trade offs in how much power is available and how much power gets wasted.  Australian Robotoics has a great breakdown of what an Arduino looks like under a thermal camera, when powered from USB and various external sources.  I don’t agree with everything that…