Awesome MOD for Walk Along Glider

This topic is related to an Earlier post " How to make a Walkalong Glider ".

Hi guys i think u have seen my earlier post " How to make a Walkalong Glider ", today iam presenting you with an awesome mod to power ur glider

you need a extra of the following things (  It is Not tough if you can find these things) :

 

1. Old picooz rc helicopter's broken tail part 

                          or

     A small Pager motor or vibrator which u may  get for free of cost  in some    

     mobile repair shops

2. 3volts lithium "button battery''

3. Small propeller

                         or

     just follow this  "   http://www.instructables.com/id/mini-airplane/  "

     to make a cheap best propeller from old can

STEP 1:

 Just draw a red line on the glider as shown in the figure (just click on the image to zoom)

STEP 2:

Now make the power booster to the glider by connecting the battery, motor and propellor as shown in the figure , you can also modify little by adding a switch

STEP 3:

Now  just simply attach the power booster to the glider along the red line depending upon the balance point or CG(centre of gravity) of the glider after several test trials as shown in the figure

 Now just rock  the glider with ultimate fun but be careful  the glider may go far away from u leaving fun.

Make a Joule Thief

In this week's Weekend Projects I show you how to make a Joule Thief. The PDF file that goes with the podcast is here(450 kB PDF file). So whats a Joule Thief? It's a little wisp of a circuit that allows you to drive a blue or white LED from a low voltage. Normally, if you want to light up a blue or white LED you need to provide it with 3 - 3.5 V, like from a 3 V lithium coin cell. But a 1.5 V battery like a AA cell simply will not work. But using the Joule Thief, it works like a charm. Not only does it work with a brand new battery, but it works until the battery is nearly dead-- down to 0.3 V. That's well below the point where your other toys will tell you the battery is dead, so it can steal every last joule of energy from the battery (hence the name). To learn how to make one, watch the video, which is available in a variety of formats.

It's a little hard to see through my fingers in the video, so here's the detailed view of the coil and winding your own.
	First, here is a selection of ferrite toroids, inductors, and transformers that are suitable for using to make a Joule Thief. Depending on the type that you start with, you may be able to use the existing wires or need to take them off and wind it yourself.
	To wind your own coil, start with two colors of insulated wire and a bare ferrite toroid.
	Take the two strands of wire through the center of the toroid.
	Keeping the two strands together, wrap them around and through the toroid again.
	Keeping the two wires together, make a few more turns through the center.
	Keep winding until you fit as many turns as will fit in a single layer around the toroid, typically 7-10 turns with thin insulated wire.
	Clip the wire leads down. Note that we have two pairs of wires: one coming out the front, and one coming out the back.
	Strip the wire ends. Take one wire from each pair of different color and attach them together.
	Solder the cross-over pair together. This is the "common" point of the coil windings.
In the circuit diagram for the Joule Thief, the common point of the toroid is the connection at the top of the hand-wound ferrite toroid, in the upper right of the diagram. This goes to the positive end of the battery. The other two wires from the toroid go to the resistor and to the intersection of the transistor with the LED. One other detail that you may need to know is the symbol and pinout of the 2N3904 transistor. In the symbol, the part with the arrow is the "emitter", the "collector" is the end above it, that also connects to the LED, and the "base" is the wire leading off to the left, between the collector and emitter. (Also remember that the end of the LED with the flat side and short lead is the end that has the flat bar in the diagram.)
	An actual 2N3904 transistor looks like this.  The pins, holding it so that you can read the text on the flat side are (left to right) Emitter, Base, and Collector. I particularly like this one because it has that little EBC legend on the bottom.
So how does it work? Pretty well, actually. (The technical discussion has been removed.) As a side note, this is not the most efficient circuit around; its beauty is that it works with such a low voltage. So, this is a great circuit to use with a dead or dying battery, and less so for use with a brand new battery.

A Simple and Cheap night -detecting LED Lamp

Here's a simple problem: "How do you make an LED turn on when it gets dark?" You might call it the "nightlight problem," but the same sort of question comes up in a lot of familiar situations-- emergency lights, street lights, silly computer keyboard backlights, and the list goes on. Solutions? Lots. The time-honored tradition is to use a circuit with a CdS photoresistor, sometimes called a photocell or LDR, for "light-dependent resistor."  Photoresistors are reliable and cost about $1 each, but are going away because they contain cadmium, a toxic heavy metal whose use is increasingly regulated. There are many other solutions as well. Look here for some op-amp based photodetector circuits with LED output, and check out some of thetricks used in well-designed solar garden lights, which include gems like using the solar cell itself as the sensor. (Our own solar circuit collection is here.) In this article we show how to build a very simple-- perhaps even the simplest-- darkness-activated LED circuit. To our LED and battery we add just three components, which cost less than thirty cents altogether (and much less if you buy in bulk). You can build it in less than five minutes or less (much less with practice). What can you do with such an inexpensive light-controlled LED circuit? Almost anything really. But, one fun application is to make LED throwies that turn themselves off in the daytime to save power. Throwies normally can last up to two weeks. Adding a light-level switch like this can significantly extend their lifetime.

Here are our components: On top: a CR2032 lithium coin cell (3 V). On the bottom (L-R): the LED, an LTR-4206E phototransistor, a 2N3904 transistor, and a 1 k resistor. This LED is red, blindingly bright at 60 candela, in a 10 mm package. It casts a visible beam, visible for about twenty feet in a well-lit room. We got the LEDs and batteries on eBay, and the other parts are from Digi-Key, but Mouser has them as well. As we mentioned, the last three cost about $0.30 all together, and much less in bulk. The LTR-4206E is a phototransistor in a 3mm black package. The black package blocks visible light, so it is only sensitive to infrared light-- it sees sunlight and incandescent lights, but not fluorescent or (most) discharge lamps-- it really will come on at night. Our starting point is the simplest LED circuit: that of the LED throwie, which has an LED driven directly from a 3V lithium coin cell. (Funny looking example here.) From this, we add on the phototransistor, which senses the presence of light, and we use its output to control the transistor, which turns the LED on.  The circuit diagram looks like this; please ignore the messy handwriting. ;) When light falls on the phototransistor, it begins to conduct up to about 1.5 mA, which pulls down the voltage at the lower side of the resistor by 1.5 V, turning off the transistor, which turns off the LED. When it's dark, the transistor is able to conduct about 15 mA through the LED. So, the circuit uses only about 1/10 as much current while the LED is off. One thing to note about this circuit: We're using a red LED. That's because the voltage drop across the transistor allows less than the full 3 V across the LED. The full three volts is really only marginal for driving blue LEDs anyway, so two-point-something really doesn't cut it. (Might be able to work around that with a cheap FET-- haven't tried yet.) And now, let's build it. You can certainly put this together on a breadboard, but there's something more satisfying about the compact and deployable build that we walk through here.
First get the transistor and the resistor. The pins of the 2N3904 are called (left-to-right) Emitter, Base, Collector, when viewing it from the front such that you can read the writing. We're going to solder the resistor between the leads of the Base and Collector of the transistor. Unusual part: hold the resistor with its leads at 90 degrees to those of the transistor while you solder. Stay safe when you do this: Use Mr. Hands. After soldering, clip off the excess resistor lead that is attached to the transistor base (middle pin), as well as the excess length of the collector pin.
Next, we add the phototransistor. Note that it has a flatted side, much like an LED does. This pin on that side is the collector of the phototransistor. Solder the collector (flatted side) to the middle pin (the base) of the transistor, again at 90 degrees. The other pin of the phototransistor, the emitter, is left unconnected for the moment. (Here is an alternate view of what that should look like when you're done.) Finally, we need to add the LED. To do so, we need to know which side is the "positive," or anode side of the device. Regrettably markings of LEDs are not consistent, so the best way to be sure is to test it with the lithium coin cell-- put the LED across the terminals of the cell and, when it lights up, note which side is touching the (+) terminal. (Usually, it's the one with the longer lead.) Solder the "positive" lead of the LED to the emitter pin of the transistor-- it's the one on the left, which doesn't have anything soldered to it. Trim away the excess lead of the LED that goes past the solder joint. Solder the other pin of the LED (the "negative" pin, or cathode) to the emitter of the phototransistor, the pin on the non-flatted side, which does not have anything connected to it yet.
By this point, there are only two pins sticking down below the components: One that goes to the resistor and collector (rightmost pin) of the transistor, and one that goes to the emitter of the phototransistor and to the cathode of the LED. To test the circuit, squeeze the coin cell between these two terminals, positive side goes to the lead touching the resistor. You can't see the LED on here because these photos were taken with incandescent lighting-- it wouldn't turn on.
Bending the leads to contact the lithium cell a little more reliably, you can try it out a little more easily. In the photo on the right, I cupped my hand over the circuit-- so the LED turned on.
To make this into an actual "throwie," you still need to add some tape and a magnet, but that's quite easily done. This one makes a pretty good nightlight attached to the top of a doorframe-- when the room lights are off, it shines a bright, bright spot on the ceiling. Where to go from here? While this little circuit can do something on its own, it would probably also be happy as part of a larger circuit. At a minimum, note that if you work with batteries that have lower internal resistance than the lithium coin cells, you should place an appropriate resistor in series with the battery before trying to operate this circuit-- or else you may put too much current through the LED. Certainly, this is one of the easiest and least expensive ways to control an LED with a photosensor.  You could also consider crossing it with some more extreme mods, like the Talkie Throwies that know Morse code, or for more extreme hackers, bagel throwies.