Control Loops
A home thermostat is an example of a closed control loop: It constantly assesses the current room temperature and controls a heater and/or air conditioner to increase or decrease the temperature according to user-defined setting(s). A simple (low-cost, cheap) thermostat merely switches the heater or air conditioner either on or off, and temporary overshoot and undershoot of the desired average temperature must be expected. A more expensive thermostat varies the amount of heat or cooling provided by the heater or cooler, depending on the difference between the required temperature (the "setpoint") and the actual temperature. This minimizes over/undershoot. The process is called PID and is implemented using a PID Controller.
Read more about this topic: Temperature Control
Famous quotes containing the words control and/or loops:
“Time in the hand is not control of time,
Nor shattered fragments of an instrument
A proof against the wind; the wind will rise,
We can only close the shutters.”
—Adrienne Rich (b. 1929)
“In the labyrinth of a difficult text, we find unmarked forks in the path, detours, blind alleys, loops that deliver us back to our point of entry, and finally the monster who whispers an unintelligible truth in our ears.”
—Mason Cooley (b. 1927)