As an engineer, I feel I have a good pulse on design esthetics. Though I’m only of lowly electrical persuasion and not industrial, I can still appreciate me some good ergonomics. For example, take a good look at the following picture of my Apple Magic Mouse:
The picture shows the bottom side of the mouse, with the battery cover off. Notice anything unique? No? The battery cover is off for a reason. Note that the two AA batteries are each in the same orientation. That is no accident.
Think of every battery-operated piece of consumer electronics you own or have owned. Probably a lot of equipment, I’m sure. Now think of how the batteries were aligned inside them? That’s right, they were in an alternating alignment, such that the positive terminal of one battery was physically closest to a negative terminal of the adjacent battery. Why?
Because this sort of arrangement has everything to do with the electrical engineer and nothing to do with the end user. It facilitates an easier printed circuit board layout, not a more logical consumer experience. From the customer’s perspective, the alternating battery arrangement seems rather arbitrary or pointless. Why wouldn’t the batteries be aligned in a more pleasingly symmetric manner?
The reason an engineer would align the batteries the way they have for eons is all about polarity. Most battery power supply circuits require at least +3V for the internal regulation. Double-A and Triple-A batteries both have a nominal voltage of +1.5V. Therefore — stay with me here — the batteries must be in series in the circuit rather than parallel 1.
Again, what does any of that have to do with the user? Nothing! I’m reminded here of the wonderful book The Inmates are Running the Asylum. In it, Alan Cooper talks about software programmers’ tendency to add as many features as possible in the absence of good management regulation. All these complicated features result in clunky user interfaces and, hence, bad user experiences.
The same principle applies to hardware design. Though engineers may be tempted to design with their own goals and esthetics in mind, they must constantly weigh those against the expectations and experiences of the end user. Otherwise, what’s the point? After all, products are made for users. Apple’s design esthetic is a model for all engineering companies.
- In a series circuit, the current remains constant, while the voltage is additive (for batteries) and voltage drop across passive components is composite, equal to the sum total of the battery input