ELEC 435

Voice Coil Actuator

The contraption below is an electric coin tosser, made from the innards of a recycled loudspeaker. The coil is a single, closely wound layer of 30 ga copper wire, 40 mm long and 20 mm in diameter. The coil is placed in a cylindrical gap which is 1 mm wide, 10 mm long, and has a radial magnetic flux density of 0.5 T.

A coin is tossed by applying a short 10 V pulse to the coil. To prevent the coil from being tossed along with the coin, this pulse is immediately followed by a -10 V pulse to decelerate the coil and return it to its starting position. The composite tossing pulse is shown in the plot below. The coin being tossed is a US Quarter Dollar.

Your task for this project is to simulate the behavior of this system, using Matlab, Simulink, or other appropriate environment. Your simulation should be as comprehensive as possible and should incorporate all of the information given above. Be sure to state and justify any additional assumptions that you make. Provide a justification for each numerical parameter in your simulation. Demonstrate your simulation with appropriate plots. Be sure to include a printout of your program with your writeup.

When your simulation is working to your satisfaction, use it to answer the following questions:

  1. If T1=10 ms, how high will the coin be tossed?
  2. How wide should the -10 V portion of the pulse (T2) be to return the coil to its starting position?