Summer is here. A broiling hot day followed by late afternoon rain. I spent the day reading, including an in depth study of a popular chip called a 555 timer. This provided an excellent opportunity to demonstrate how asinine electronics authors can be. This chip has been in common use for forty years and one expects there to be dozens of sources about just what the chip is and what it does. Wrong. The world is full of magnificent morons.
To see an example of degenerate documentation, try reading the Wikipedia description of the 555 timer written by a constipated ape. You can read it, but you won’t know anything more when you are done. By comparison, allow me to write a few paragraphs description of the same chip and decide which source gives you more information.Here’s my version: Have you ever wondered how those bicycle LED flashers work? That’s probably a 555 timer, although in reality, it doesn’t time anything. But when you connect it to a resistor and a capacitor, it turns off and on in a precise manner, allowing it to be used to “time” very accurate intervals. Electronically, this is most useful, as you can change intervals by changing any combination of the resistor and capacitor. This on/off action is instant; it does not slowly fade in and out.
At very low on/off rates (say 120 times per minute), it can make a speaker click. That is an electronic metronome. At mid speeds (3,000 times per minute), it can make speaker buzz, like a doorbell. And above that speed, who cares? The 555 can be used to operate electronic switches. It does this in two ways. The first way is you press the switch and say a light comes on. When you release the switch, the light stays on (it is actually pulsing on/off really fast). If you want to sound like a nerd, you call this the “astable mode”. You can tell it is astable if you look at the chip and see pins 2 and 6 are connected.
The second way a 555 operates a switch is quite different. When you press it, the light comes on but when you release it, the light goes off. That’s called the “monostable mode” and pins 6 and 7 are connected. It probably seems dumb to use an integrated circuit for such a simple tasks, but when you need to be exact, this is the way you do it.
Thanks to these features, the 555 can be used in almost countless ways. Since you followed my explanation so well, I’ll tell you about one technical use for the 555. Sometimes, like in computer hardware, you want many things to happen at the same time. Well, you connect a reliable 555 circuit that is flashing on and off, and design your other components to wait until the next 555 “on” signal and then all work at once.
There, was that so bad? The rain lets up later and I went to Big Lots for some DVD movies on sale. Hey, even I don’t study all day long. I read for relaxation, too. Many times I’ve praised the paradise of Borocay Island in the Philippines. Today I read an article in some English newspaper that, sadly, says the world has discovered the place. I don’t mean that literally because millions of people know where it is. Now it is like Mexico.
When I was there, no motor vehicles were allowed and therefore there were no roads. But they’ve built resorts and put in electricity. It was a sad day for the island when that happened. I have not been there in 25 years. Paradise isn’t good enough for some tourists. They need a hot tub as well. Thank goodness I saw it before it got civilized.
I studied some old documents concerning the German exploration of Antarctica. Since this happened in 1939, it is generally glossed over in history books. The expedition and Schirmacher Oasis are not even mentioned in the otherwise complete work “A Continent For Science”. Of course, there is always the crowd that believes it was a Nazi UFO base. What is known for certain is that photos of German flying saucers had a lasting effect on post-war American hub cap design.
Guess who is instituting DNA testing for membership? Indians with casinos, that’s who. It seems where Indians in America have established casino profit-sharing, they have relations “coming out of the woodwork”. One tribe grew from 30 members to 1,000 in one generation. The testing is nothing new. Over 500 tribes already use them to catch freeloaders. Critics say the testing undermines cultural values (huh?) and could wreck families over paternity issues. Critics who don’t want to be caught, that is.
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