7. Open Loop System

There are two types of computer control system:

The first type, Open Loop System, only looks at its input signal in order to decide what to do.

It takes no account at all of what is happening to its output.

Examples of 'open-loop' systems:

a) You set the microwave oven to run for two minutes.  After cooking
for two minutes, the control system turns the microwave off. It has no idea whether your food is still frozen, burnt or cooked perfectly.

• Switching on a light, it does not check if the bulb is actually working.
• Toaster - most have just a simple timer, so easy to burn or under-toast the bread.
• TV remote control, it send the signal but does not know if it actually worked
• Tumble dryer running on a simple timer, clothes might still be wet at the end

The main advantage of an open loop system is that it is very simple, all it does is take in a command or value and produces an output action of some kind.