Table of Contents
Cascade Switching Hardware and Software
Cascade switching allows the Arduino, with a limit of 20 mA output, to control solenoid valves that need 0.5A or more to actuate.
The salinity control algorithm uses on/off control with a dead-end determined by measurements of system variability. The measurements are described in the next section. The following slides give a high level overview of why a deadband is used, and how the response time of the system also needs to be taken into account.
- Study document for review of salinity control concepts and system behavior.
Measurements to Characterize Your System
Mass Balance Models for Salinity Control
- Notes on using mass balances to compute the required correction when salinity is disturbed from the set point
Sample Hand Calculations
- Solution to in-class problem on adding mass to correct the salinity in the fish tank
- Screencast on problem on correcting the salinity of the fish tank (21:15)