I figured the best place to get my feet wet was with one of those electronic kits like Radio Shack sells. Bunch of components, instruction manual, compact size, 30 projects to get you rolling.
So I'm working on it and paying attention, and some questions are forming (after just four projects, too. I'm not sure if that's good or bad).1) In a simple light circuit, using an LED, batteries, and a resistor, does it matter where the resistor is placed? The book cautions that LED's can burn out from too much power. Does the resistor stay before the LED, can it be placed after, or does it matter as long as one immediately follows the other in series?
2) The kit features two..."regular" (I guess they might be called disc) capacitors and two electrolytic capacitors. I noticed the schematics, when they depict the electrolytic ones, include a positive symbol by the flat line instead of the curved. So they can obviously only be connected in the circuit one way, positive current to positive terminal on the capacitor. But what about the smaller disc ones? Does it matter for them?3) The next project is building a crystal radio, powered by radio waves. It mentions attaching a wire to a ground. Buying a shortwave antenna for simple experiments strikes me as overkill, and the pipes in my place are PVC plastic. Then I remembered my computer. The case that I attach my anti-static wrist strap to is a ground. Can I just attach the ground wire to the case of my computer (with the computer powered off, of course)? Failing that, I was told that the negative terminal of a battery is considered a ground. Can I just wire it to that?
4) What gives something the ability to be a ground, anyway? Just that it can readily absorb an electrical current? It seems to me that, if the computer case idea is workable, then as long as the voltage is small, almost any sizable metal object would make a sufficient ground.5) Big question: I was taught in science class years ago the electricity actually flows from the negative terminal to the positive. Even though the book says the other way around and schematics for things like diodes imply power goes from positive to negative, when it gets to transistors, it says the electrical path is emitter to collector or emitter to base. Did they just mix the words up, since the schematic shows the flow going the other way, or am I missing something?
Sincerely, Pete Holland Jr.