1. Technological Systems

2. What Is a System? A group of interrelated components (things) that work together to achieve a desired goal. A technological system produces results through the use of technology. A system may be huge, like a space shuttle. Or it may be small, like a cell phone.

3. The Basic System Model All systems include an Input, Process, and Output During the Process the seven technological Resources are used. Input The desired Result (What you want to happen) Output The actual result Process Action part of a system. Combines resources that respond to the input to produce a result. People Capital Time Information Energy Materials Tools and Machines Resources

4. Open-Loop System A system that has no way of monitoring or adjusting itself is an open-loop system. Since you can’t control the temperature, only the time the microwave is heating your food, it may come out too hot or not hot enough. Input A hot meal Output Food is warm Process A microwave combines the resources to heat your food for a certain amount of time. People Capital Time Information Energy Materials Tools and Machines Resources

5. Can You Think of Other Open-Loop Systems? Woodstove Does the temperature remain constant? Washer/Dryer Do the clothes always come out clean and dry? Train Does the speed remain constant while travelling uphill, downhill, or on a flat?

6. What Is Different in These Systems? Bicycle Rider watches road and adjusts pedaling or braking. Car Speed Driver looks at speedometer regularly and adjusts speed as needed or sets cruise control. Furnace Temperature is controlled by setting thermostat to desired level.

7. Closed Loop System A system that monitors and adjusts to get the desired output. Input Comparator Controller Process Resources Output Monitor Feedback Loop

8. Closed Loop System Input Go 30 mph Output Car speed is 50 mph Process A car combines the resources to move the car and transport the riders. People Capital Time Information Energy Materials Tools and Machines Resources Comparator Driver compares actual speed to desired speed. Monitor Driver sees car is going too fast. Feedback Loop Combination of speedometer, driver’s eye, and driver’s brain form the feedback loop. Controller Driver presses brake or accelerator.

9. Open or Closed Loop System?

10. Image Resources Microsoft, Inc. (2008). Clip Art. Retrieved December 10, 2008, from http://office.microsoft.com/en-us/clipart/default.aspx