Week 2: Circuitry (Digital Approach)

There are many different ways that the circuitry could be designed in order for the pet feeder to work. Based off of the knowledge that a DC motor would control the revolutions made by the pet feeder cover, the group debated the potential use of resistors within the circuit.

The group discussed two methods in particular. The first being a circuit that would make use of a 12V DC motor connected to different resistors. Each circuit path would have its own set resistance; which would correspond to a specific (user-input) feeding setting that allows for a set degree of rotation of the pet feeder cover. The difference in resistance would be due to an increased number of resistors (in series) for each circuit setting (see Fig 1.)

Fig 1. Pathways of Different Resistance

The second option would make use of a POTENTIOMETER; which is a small sized electronic component whose resistance can be adjusted manually (a manual variable resistor - see Fig 2.). It is used in various electronics e.g. volume knobs in music systems, fan regulators. Based on this concept the group was able to visualise how the user-dependent dial would help control the number of revolutions made by gears and ultimately the degree of rotation made by the feeder cover.

Fig 2. Standard Potentiometer