One of the first things we covered in my Electronics course at the tech school was Resistors. Basically these are little do-dads that reduce the amount of current going into sensitive electronic components. So that they do not quickly become crispy former electronic components. They come in a crazy variety of sizes. There are several ways to determine how much "resistance" a unit like this has.
You can read the colored bands, which correspond to a coding system.
I actually already knew the color codes. The system dates way back to the 1920's and is virtually the only thing I remember from Junior High. We took various tech courses back then (metal work, printing, drafting were a few of the others ) and I vividly remember the instructor giving us the mnemonic that burned this bit of non useful information into my brain. Fifty years later I could recite it.
Could, but totally won't. It was inappropriate then and really, really inappropriate in the modern age. It involves somebody named Violet and on this matter no more shall I say.
Or, you could read the resistance with a multimeter. Here's a really swell one we use at school. I think they cost $250. The reading here is O.L. which means either overload or open circuit. The resistance of an air gap between the two points or contact leads is really high. See, that's why they tell you it is safer to not touch things with electricity in them.
Or I could use the antique version I got for five bucks at the surplus store.
You can measure the resistance of all sorts of things. Here's the resistance of the (negligible) current running from one hand straight across to the other.
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| Thats on the 10K setting, so about 30,000 ohms of resistance. |
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| I'll talk about reading Amps some other day. Advance hint...don't do this with the ampmeter! |
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