Design and Build a Switch-Controlled Turntable

1. Design and Build a Switch-Controlled Turntable Name: Dean McDonnell Supervisor: Dr. Maeve Duffy Electronic Engineering Final Year Project

2. Objective of Project • Design and Build a portable switch-controlled turntable • Table must manoeuvre in an upwards/downwards manner • Must be controlled through an IR Transmitter • Design the table so as to fit under an assortment of beds • Rotate a maximum of 5kg Electronic Engineering Final Year Project

3. Background • Previous version designed in North Carolina for children with severe disabilities. This is called the “Lazy Susan” • Extreme disadvantages before this invention as they could not independently retrieve toys • Could not choose between multiple items Electronic Engineering Final Year Project

4. Background “Lazy Susan” in Action Building of the “Lazy Susan” Electronic Engineering Final Year Project

5. Background • Dramatic change of lifestyle for both child and guardian • Allow the children to access toys without teacher intervention • Teachers, therapists, parents and children all gained independence Electronic Engineering Final Year Project

6. Design Goals • Consist of a fixed table along with a turntable • Controlled through an IR transmitter • Rotate in a circular manner • Manoeuvre upwards and downwards • Controlled by separate motors for different tasks Electronic Engineering Final Year Project

7. Design Goals • Rotating Motor will be able to rotate up to 5kg • Powered by a 12volt power supply • Portable • Attachable to different types of beds Electronic Engineering Final Year Project

8. Approach • Technology Review was completed before a User Needs Review was commenced • Data sheets were researched for different motors • Different companies were contacted • Bi-directional motors were a must • Rotational speeds were always questioned Electronic Engineering Final Year Project

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10. The Selected Motor Electronic Engineering Final Year Project

11. Approach • Tests were then completed within the lab • Observation of the rotating parts of the motor • Starting and stopping times and the speed of the rotation • Current being drawn and the voltage needed Electronic Engineering Final Year Project

12. Progress • Rotational Motor is researched and found • The H-Bridge is now also found • More testing needs to be completed for the H-bridge • DC position controllers and speed sensors are currently being researched Electronic Engineering Final Year Project

13. H-Bridge • Electronic circuit which enables a voltage to be applied across a load in either direction • H-bridges control the polarity of the motor • Control the braking of the motor Electronic Engineering Final Year Project

14. H-Bridge Electronic Engineering Final Year Project

15. The Next Steps • The next motor will need to be found • To control the upwards and forwards movement of the table • Physical designing of the table • Installation of the motors Electronic Engineering Final Year Project

16. The Next Steps • Setting up of the IR transmitter • A risk assessment will have to be concluded • Affects the health and safety of the user Electronic Engineering Final Year Project

17. Potential Hurdles/Concerns • The safety of the product when completed • The cables/wires that will be attached to the table – will they be hidden? • Physical designing of the table so as to fit on the assortment of beds Electronic Engineering Final Year Project

18. Conclusion • Continuing at a slow rate • Result of the difficulty of finding the rotating motor • Steps involving the H-bridge and the speed sensors should be quickly achieved • Difficult part involves the programming of the IR Transmitter Electronic Engineering Final Year Project

19. Questions? Electronic Engineering Final Year Project