Blog

The Application: Gas-Pump Controller Design The Clean Petroleum Company (CPC) is interested in reducing pollution in the atmosphere. When people overfill their gas tanks gas is spilled and evaporates causing air pollution. To minimize this problem, their pumps currently turn off when the back pressure from the gas tank gets too large while the nozzle handle switch is activated (i.e., compressed). They have asked you to design a controller that does the following: If the nozzle handle switch is depressed and the pump pressure sensor indicates low pressure, then allow gas to be pumped. If the pump pressure sensor indicates high pressure then turn-off the pump. (The system clock pulses every one second and you may assume that once the pump shuts off, the pump pressure returns to normal within one second.) Once the pressure returns to normal, allow the pump to be controlled again by the nozzle handle switch. If the pump pressure sensor indicates high pressure a second time, your design will permanently shut down the pump until reset by gas station personnel. (Note that there are two inputs to your synchronous machine: the nozzle handle switch position, and the pump pressure sensor indicator. Your synchronous machine has one output that controls the pump.) All information to complete this design may not be specified. Write down and report any assumptions that you make in your design. Be sure to use debounced “logic switches” for driving the clock input to the flip-flops. 31. LAB MANAGER’S RULES FOR PERFORMANCE You will only be allowed to do the project during the assigned times. If you miss the calendar dates, you will not be allowed to do the lab project unless you have a WRITTEN NOTE signed by your course professor. 2. Hardware Demo: You must have your lab report completed before you start the lab demo since you will need to give it to the lab TA at the completion

of the demo. (Having your report finished will help you complete the lab project in the allotted time.) YOU WILL NOT BE ALLOWED TO DO ANY PRACTICE RUNS OF THE LAB PROJECT INSIDE OF GWC-273. You must be ready to complete the entire lab project when you come into GWC- 273. However, outside of GWC-273 you may consult with anyone you wish to obtain help in designing the lab project. 3. Hardware Demo: You will have ONLY 2 HOURS to complete the lab project in GWC-273. You must work alone with no lab partners to assist you. No friends, relatives or tutors may be with you. You may bring any textbooks, notes, reference books, lab notes, lab experiments, and lab reports into the GWC-273 lab area. You will definitely need your PIN-OUT diagrams of the IC chips. You will not be allowed to take any breaks from your 2-hour shift except for restroom and water. (Sorry: but you cannot bring in your own breadboards and IC chips because that would give you an unfair advantage over other students in the GWC-273 lab.) 4. Notice: Make sure you do the project ONLY during the hours in which any EEE/CSC 120 Hardware Lab TA is on duty inside of GWC-273. Only these TAs can assist, monitor and check- off your project. TAs in other courses are not permitted to assist you do the lab project. 5. You will be able to use any of the IC’s we have in the lab for completing your project. Check in the lab if you are not sure which IC’s are available. Be aware that in ERC 273 we DO NOT have the following IC’s available: 7421, 7430, 74133, 74174, 74375. Hardware Lab TA’s on duty will assist you ONLY if there is broken lab equipment. Hardware Lab TA’s will NOT assist you with troubleshooting or debugging your project lab design circuit. Notice: If you are thinking of omitting this lab project from your schedule, be reminded that parts of this lab project may show up on the final exam for this course!