Some Questions From Beginner

Almost all of your questions are rsolved by a more thorough study of general electronics. While robotics encompasses electronics, it's only one of several disciplines, and it's a very large field of study. Most robptics products and books assume you will self-educate in the area of electronics.

Fortunately, electronics doesn't change very rapidly, so even an older text from the library may be helpful (but not more than about 10 years). There have been several books that discuss electronics basics, theory, component identification, schematic reading, and other fundamentals. Even though many of these books are quite good, no one book answers it all. You'll probably want to read through several.

Since you elected to go with the Boe-Bot, with electronics already assembled and tested, already there is no reason to learn these things before being able to play with the robot. You can read up on electronics while gaining experience with robot, and that includes the also-important aspect of programming.

As for the batteries, you need to read up on corporate lawyers to understand why they have the warning! If one battery ever explosed, the lawyers want to warn everyone else, for fear of million dollar liability claims. It should come as no surprise that batteries can explode if you toss them into a fire (people do this for fun), or short out their terminals. Under normal use batteries are quite friendly...

-- Gordon Author: Constructing Robot Bases (Forthcoming) Robot Builder's Sourcebook, Robot Builder's Bonanza

What happen when a AA alkaline battery explode? Does it explode like a bomb or does it explode like burning? What can I do to prevent this from happening? You actually experienced a battery explosion?

Tony

----- Original Message ----- From: "Tony" Newsgroups: comp.robotics.misc Sent: Friday, November 28, 2003 10:08 PM Subject: Re: Some Questions From Beginner

Yes I have experienced it. Years ago I found two seemingly almost dead 9 volt batteries while helping a friend clean his shed. I stuck them together (doing this shorts both batteries), threw them in the trash pile, and continued on. About a minute or so later, I heard a mysterious loud crack, like as loud as an M80, but higher in pitch. We eventually figured out it was the batteries that blew. All that could be found of the battery was a few sticky paper remnants. I have also had a battery, some "non-rechargeable" type, blow when I accidently left it in the charger too long.

They blow because they are sealed and cant hold the pressure. Drawing current (or charging) heats the battery, expanding the chemicals inside. At a certain point the vessel just gives and bang. I imagine there are no flames, and they just bust apart violently spewing their innards.

Prevention? Dont short, or near short, batteries to the point they get hot and blow. A 1 hour discharge rate should be safe for regular alkaline batteries. Below 1 hour the efficency sucks anyways.

--Ryan

1.) Just be aware to not short out batteries or overcharge the rechargeable ones. 2.) Usually the voltage is too low to be a problem on your skin. You have to overcome a fair amount of skin resistance. 240vac is a diffeerent matter, it''ll kill you. Getting into a safety minded frame of mind is important. Whether it's 110vac or 220vac we all have it in our homes, and it is dangerous, but we all know better and take precautions not to kill ourselves. Except for those going for the Darwin Awards. :) 3.) Do not wear wool. Cotton works best. Do not wear leather soled shoes. Take a little dishwashing detergent and add it to some water, put it into a spray bottle and then slightly spray the carpeting around the area you are going to work in. This should suffice for most purposes. Most devices have some sort static protection built in, but one should not push their luck. Mainly being aware of it is enough to allow you to take precautions. If you walk around your house andyou get zpped when you touch the doorknob you know you have serious static problems. In this case you need to take the more advanced anti-static precautions. 4.) yes reusing things is very popular. It's up to your imagination and skill as to what is reusable or not for you. Old printers and scanners offer the most neat things to reuse. Of course toys are always very popular too. 5) Getting familiar with electronics and all their parts is important. There are a lot of books on this that can help you. many parts can be recycled, but identifying the proprietary parts in some things is next to impossible. In this case a manfacturer puts their own private part numbers on a part to prevent the competition from reverse engineering a cheaper one. Plus it may make in house inventory processses easier. 6) There are many electronics books already there, no sense beating a dead horse so to speak.