Electronic Engineering Final Year Project

Design and Build a Switch-Controlled Turntable

Name: Dean McDonnell

Supervisor: Dr. Maeve Duffy

Electronic Engineering Final Year Project

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

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

Background“Lazy Susan” in Action

Building of the “Lazy Susan”

Electronic Engineering Final Year Project

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

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

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

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

Electronic Engineering Final Year Project

The Selected Motor

Electronic Engineering Final Year Project

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

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

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

H-Bridge

Electronic Engineering Final Year Project

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

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

Electronic Engineering Final Year Project

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

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

Questions?

Electronic Engineering Final Year Project