Tuesday, March 31, 2015

Electric Grid

Yesterday there was power outage in many cities in Turkey. Build an electrical grid project with load balancing and also demonstrate cascading failure. Do this first as computer simulation and then use real parts.

Simple design with a DC relay demonstrating load balancing:

When a second resistance is connected in parallel, current increases to 2i. This increases the voltage in the relay to 2*Vr1 which closes the relay. When thre releay is closed, the second battery becomes part of the circuit (parallel to the first one). Both resistances will have a current of i. If these were light bulbs they would have the same amount of light output.

If we didn't have a second battery and the relay, adding the second resistance would decrease the resistance by half and cause the current to double which would empty the battery in half the time. What we achieved with our design is having the same electric output time.

Note that if we added the second battery in series, i2 would be 2*V/(R/2) = 4*i. Each resistance would have a current of 2i which could damage the appliance represented by the resistance (in our case, light bulbs).

Implementing the system with real parts would look like this:


Monday, March 2, 2015

Tracker free video analysis and modeling tool

https://www.cabrillo.edu/~dbrown/tracker/

https://www.youtube.com/watch?v=La3H7JywgX0