PHY 242 Laboratory for 12/07/99

Special Schedule Note:

Next Thursday, Nov 11 is Veteran's Day and there are no classes. The following Thursday, Nov 18 will be Exam III. The Thursday after that is Thanksgiving. Thursday, Dec 2 following Thanksgiving will be another optics lab, details of which will be given later. The following Tuesday, Dec 7 has been rescheduled as a Thursday. On that day you will give a short presentation as outlined below. (It may seem early, but the sooner you begin, the better!) Wednesday, Dec 8 is also scheduled as a Thursday. We will use that day to complete the presentations if necessary, and as a general tutorial.

Granville T. Woods was born in Ohio in 1856. He went to work at a machine shop at age 10 and never completed elementary school. He became interested electrical devices around the age of 16, working as a train engineer. Although his first patent was for an improved steam boiler, he quickly focused his energies in the area of electricity. He had an impressive array of inventions, from a railroad telegraphy system to a safe and efficient light dimmer used on the theater stage. He had over sixty patents by the time of his death in 1910. He was well-known and respected in the electrical engineering community as the "Black Edison".

A 10 Minute Presentation

During the final regularly scheduled laboratory session on Thursday, December 2, you will give an approximately 10-minute long presentation on one of Mr. Wood's patented inventions that you find particularly interesting. The presentation should provide a description of the invention and its purpose. In addition, you should focus upon the physics relevant to the invention. An additional 5 minutes will be available to field questions from your classmates.

The purpose of this lab is to provide your classmates with a concise and comprehensible description of the invention and how it relates to the principles we've studied in physics. You are strongly encouraged to begin preparations early and review your talk with me prior to the presentation. I can help not only with the physics, but also with the mechanics of the presentation such as transparencies or models.

Selecting an Invention

There are 15 inventions from which to choose. The list below provides a brief description of the device. Clicking on the title will allow you to view a copy of the original diagram from the patent application. (I apologize for the poor quality of the scanned images.) The intent is to allow you to at least narrow your preferences. If the links provide sufficient information for a decision, you may immediately email a request. (You may also submit several requests, specifying first to last preference.) If that invention has not yet been reserved, then it will be assigned to you. If you need additional information (or a a better look at the diagrams) to make your choice, you can view complete copies of the patents in my office. Once you have a "reserved invention", I will provide you with your own photocopy. Obviously, the sooner you choose, the more likely it is that you will get your first choice.

• Induction Telegraph System (#373915)
  An induction system for telegraph or telephone communication between moving trains and/or train stations.

• Relay Instrument (#364619)
  An induction relay for telegraph communications.

• Polarized Relay (#366192)
  An improvement of the induction relay for telegraph communications to be used aboard trains that was not as sensitive to mechanical vibrations.

• Electro-Motive Railway (#385034)
  An improved system to distribute power to electric trains lines and side tracks.

• Railway Telegraphy (#373383)
  A system to provide electrical connection to external lines for telegraphy aboard trains.

• Railway Telegraphy (#388803)
  A system for creating induction pulses along conducting lines for railway telegraphy.

• Automatic Safety Cut-Out for Electric Circuits (#395533)
  A circuit breaker for high tension lines.

• Galvanic Battery (#387839)
  A zinc-carbon battery. You'll need to look into a small bit of chemistry for this one.

• Telephone Transmitter (#308817)
  An early version of the diaphragm microphone.

• Apparatus for Transmission of Messages by Electricity (#315368)
  A combination telegraph and telephone reciever/transmitter.

• System of Electrical Distribution (#569443)
  This is a voltage control device that allows "dimmer" control for lights and motors. This invention was inspired by his oft attendance to theatre productions.

• Electric Railway (#667110)
  An improvement to one of his earlier inventions that controls current distribution to the various motors and other electrical devices of an electric train.

• Electromechanical Brake (#368265)
  An electromagnetic brake in which electric current is use to control the power delivered to railway brakes.

• Electro Magnetic Brake Apparatus (#371655)
  An improvement over the previous patent. The mechanical construction is probably as interesting as the electrical aspect.

• Telephone System and Apparatus (#371241)
  A telephone system that reduces induction interference from other power lines.