T&L Publications

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>I have seen it compared to standard NTSC and really don't see that great of a difference in picture quality.<hr></blockquote>There isn't ANY difference! You can SEE the difference if: 1. Your vision...

I love my flyswatter. I "juiced" by adding a capacitor to the output. When I'm messing with the car (changing oil or somethin'), a cloud of mosquitoes swarms around me (live next to a creek). BUT--- really there are only a dozen or so; the swatter takes them all out. Each dead biter kills ...

Radio SHack had a voice-recognition chip ten years or more ago, speaker independent. Only had commands like "stop", "go", "turn left", "right turn", etc. I bought two of the chips. Know anyone with real old RS stock???

Why can't you just use a 7107 voltmeter chip, with direct-drive LED outputs? Tie a pot into your tuning dial to drive the meter input, and calibrate the meter to display the correct numbers (it's made to display up to 1.999). The numbers should be very stable and repeatable. And with the 7107 (or 71...

I bought a Hallmark Christmas ornament a few years ago, something about the "Bearenstein Bears". It had a nice fireplace, with living-room-floor and mantle etc. (you had to buy the bears extra). But their FIRE! Ugh! They thought a FIRE could be simulated with a fast-flashing red LED! Their...

www.mpja.com www.goldmine-elect.com www.sciplus.com <p>Do an internet search on "surplus electronics"...<p>PS: sciplus has gadgets, toys, hardware; I bought everyone an "electric flyswatter", $10, for Christmas once. Knocks flies silly *they smoke and die if they stay on the gri...

lm3909 makes an excellent flasher. It will flash a super-bright LED from an alkaline "D" cell for 3 years. Excellent car alarm simulator.<p>NS applications handbook has dozens of 3909 circuits, from alarms to dual-color-flashers to a radio.<p>I'm not sure how you're gonna control the speed...

4038/4538 is a dual timer; it is edge triggered, so it should work for you (make certain the other trigger is tied toits idle rail...). HOWEVER---you can tie pin 2 of 555 high with a 100k, and trigger through a .01µF cap--should work fine...<p>(a 555 of course triggers on LOW...)

I wouldn't go much over-voltage-ratinged with an electrolytic; they have a bad habit of changing values if you severely under-drive them.<p>Drive a 20µF 110V at 6 volts, you may find it has changed to 5µF after a while...

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by mikea1962375: OK, I am lost. If th coil is 0.000212 henries, how much will the diameter, turns and wire length be? Does anybody know? Also, what gauge wire muct I use? Or what w...

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by mikea1962375: First, what does the comma mean between 0,43 in one of your equasions. Also, how do I solve it? there are four variables, and I only know two of them. Thanks <hr><...

BTW, the symbol "^2" is generally SQUARED. So: L=(D*N^2)/(l/D+0,43) (l/d + 0.43)(L) = (D)(N^2) (l/d + 0.43)(L/D) = N^2<p>Thus N is the quare root of the quantity [(l/d = 0.43)(L/D)]<p>You might start off GUESSING "l" at an inch, and see if you can wind it tighter; then recalculat...

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by mikea1962375: I'm confused with what you told me. I have never made a coil before, except for small 5-turn ones that said in the book to do 5-turns. If I wanted a crossover for ...

Buy an LM386 amplifier chip. $2 from Radio Shack, <$1 elsewhere. Works from 4 volts to about 15 (6 or 9 is ideal). Very simple---no extra parts (except for the 200µF speaker capacitor), it has a gain of 20. Add one more capacitor, it has a gain of 200. An additional capacitor + resistor for bias, on...

What's wrong with making an air-cored-coil? Just a few turns will do it, and it's easy to wind one. You can use a bobbin, or a simple cardboard tube. A bottle of nail polish and a couple of bread ties will finish it up just right...<p>You can probably use the "X(l) = 2 &#183 &#182 &...