Due Tuesday 1.24.06
I hunted around for a while on the web looking to get information to feed into this self test. At a certain point I started realizing that I was learning lots of interesting things and perhaps I should ask you to go through the same process as part of the learning experience. So...... I am going to ask you to dig up some information and then use it to articulate and explain the electrical power balance in an automobile. We'll hope that the car jockeys in the class are totally on top of this one. If you still have the manual for your car some of this information may be in it and there is lots on the web.
Your car/truck battery:
CCA (Cold Cranking Amps) is an important rating for your battery. What is the CCA rating of your battery (or it's recommended replacement)?
What is the temperature at which this rating applies? Why is the CA higher at higher temps?
What is the power delivered by your battery under these circumstances? Is this + or – in our electrical conventions?
What is the RC (Reserve Capacity) for your battery and what current draw is this based on?
How much total charge does this mean is stored in your battery at 12 V?
What is the total energy (in Joules) stored in your battery when it is fully charged?
At what rate is your battery intended to be recharged? (a current is your likely answer but maybe not the same a the trickle charge rate)
Your alternator and lights:
What is the power rating for each of the typical lights on your car from the headlights to the tail, brake, running, and signal lights?
How much current does each light draw when it's on?
How much current do the various instrument systems in your car use? You might need to look at the fuse box to get an idea for maximum usage. Ignore luxuries like the radio and CD players.
What is the total potential current demand for your car?
How much current does your alternator produce? How much excess current does your alternator produce above the minimum needed to operate the car?
Can you put in a 50 W stereo system without replacing your alternator?
... and there are many more questions of interest but this will do for now. Here's a link to some folks who make it their business to provide software to help automobile designers solve these questions
http://www.synopsys.com/products/mixedsignal/saber/auto/elec_power.html