Sunday, March 1, 2009

Generators

Revision

Force on currents = motor


  1. wire in B field

  2. parrallel wires

  3. loop creating torque - DC motors make the inner rotation solenoid fight the field

Faradays Law


1. Back voltage = - time differential of B*a


2. wire cutting a field is a battery


Lenz's law - practical Faraday - Eddy currents make a solenoid that resists motion. Motion turns into electrical energy and heat

  1. dropping magnet - solenoids are made that arrest fall turning energy into heat

  2. spinning disk - two solenoids are made opposing entry of a magnet, and dragging it back

  3. inducation furnace for cooking, eddy current heats metal


Homework SUMMARIZE CHAPTER 8 finish half yearly for correction.


Generators


1. Direction of current through (1) + charge right hand slap (2) lenz law


2. Slip AC- Split DC


3. Rotating faster = higher frequency and higher voltage

Transformers

more loops- more volts

Step up for efficient power transmission. P = I x I x R

eddy currents reduced by lamination. layer of insulators.

Step down to make voltage Kid friendly.

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I come from a Science family: My father Geoffrey Hill was Australia's first computer programmer on CSIRAC the fourth computer in the world. He is credited with invention of Computer music and the development of “Interprogram” a language before Basic. My PhD is in Atomic and Molecular Physics. I have researched the activated oxygen layer above the ozone layer, and 'Assigned' the world's smallest molecule. At the University of Toronto I researched high power UV lasers. I have specialized in automation in fibre optics. This developed into research in Machine Intellect and Robots. I have enjoyed work as an Explainer with Questacon and my time as a part-time soldier. I currently teach High School Science at Epping Boys’ High.