Opt Out of Prescreen Credit Card Offers

I’m not sure how many people are aware of this so I thought I’d share.  I used to get TONS of credit card offers in the mail.  On a daily basis I would get probably three or four letters.  Capital One was the biggest offender.  They would send me a letter practicaly every day.  Well, that has all stopped now.  I went to the Opt Out web site and registered.  Now the only credit card solitations that I recieved are from the one card the I carry.  Those are still annoying but the volume has been reduced dramatically.  Here’s the government link for more information which also includes the opt out link.

btw….do you know that one of the ways crooks rip you off is by stealing the credit card checks from you mailbox?  Opting out reduces that chances of that happening.  Also, it’s a good idea to empty your mailbox everyday since these thefts typically happen at night.  Here’s the link…..http://www.ftc.gov/bcp/conline/pubs/credit/prescreen.shtm

Home Inventory Software

I think for 2008, one of my goals is to do a thorough job inventoring the home.  I’ve talked with people that didn’t do this and ended up with major problems trying to recover a loss.  I haven’t tried this softward yet but I’ve heard from others that its very easy to use.  Here’s the link…

Know Your Stuff

PWM for the PIC18F1330

Here’s a little example code for the PIC18F1330 that generates 3 different PWM signals.  It’s done with MPLAB and HI-Tech’s PICC-Lite compliler.  It’s probably a little over done in that I wanted to be able to just enter a decimal value for each of the duty cycles.  That resulted in some code that is a little memory intensive.

I just picked up the CCS compiler and my understanding is that the CCS libraries will allow me to do a little more with less.  I plan on writing some code for comparison.  I’ll post it when I’m finished.

First, here’s the configuration …put this in a separate file called configuration-word.h.

configuration-word.h

Here’s the Main loop…

main.c

You’ll see wnen you examine it that I should have put some of the code into functions.  That would have helped it’s size conserably.  Oh well, maybe another time.

Rich Dennison

Regenerative Braking

So when your neighbor comes over to check out your new hybrid car – tell him about the brakes! 

While it’s true that most cars have a complex braking system especially when you consider anti-lock systems, they just aren’t as cool as the regenerative braking systems on hybrid electric vehicles.  Why regenerative braking?  Well, it really comes down to a balance between electrical power required for all vehicle systems and the power that the battery can supply over time.   When your hybrid is operating purely on battery power you are taking away the reserves of your battery.  It needs to be replaced eventually.  This battery charging process occurs during the drive cycles when the engine is running at cruising speeds.  The engine turns the generator and it supplies electrical power back to the battery.

So what does this have to do with your brakes?  Well, the engineers that have developed this complex system have determined that the time charging the battery in the engine driven drive cycles may be too infrequent for some drivers.   Under this scenario, you would take a little bit out of the battery every day without putting enough back.  It is sort of like making a small withdrawal out of you savings account everyday.  It goes unnoticeable for quite awhile and then suddenly you’re broke.  You would be left wondering why your engine runs all the time and your fuel economy took a nose dive.  The engine would have to run constantly to get the battery back to a full state of charge and then the cycle would start all over again.  To prevent this from happening, other sources of energy needed to be found. 

Fortunately, braking offers a solution.  In your normal vehicle, brakes use a hydraulic system to put pressure on the brake pads to clamp against your rotors to stop.  Well, hybrids can do the same thing but it also has another system it can use – the generator.  The generator is what powers your wheels when you’re operating under electric power.  One of the characteristics of electric motors is of course when you apply a voltage to them they turn.  In our hybrid, it powers us down the road.  One of the other characteristics is that if I turn the generator mechanically it will generate a voltage.  It can operate in both directions.  In our hybrid, when we want to slow down, we switch the generator so that the wheels drive it and it produces power that is fed back to the battery.  The mechanical friction of the generator begins to slow us down.  If we need a sudden stop that the generator can’t provide, we still have the normal braking system.  Every little bit of energy can return back to the battery is that much less you have to provide during the engine running scenario.  That helps us with our fuel economy as well because when you have to charge the battery during the engine cycles, it requires more work for the engine which requires more fuel.  So when you’re neighbor wants to check out your new hybrid, give him an earful on how your regenerative braking system works.

Rich Dennison