එළකිරි Circuit පන්තිය

udarapath · Sep 29, 2011

එළකිරි Circuit පන්තිය

Circuit හදන්න ආසාවක් තියෙන අය එන්න හරිම සරලව කියල දෙන්නම් :yes:

හරි ඔන්න පටන් ගමු. මුලින්ම සරල Circuit හදන විදිය කියල දෙන්නම් කෝ

ඉස්සෙල්ලම ඔයාලට මෙන්න මේ Item ටික ඉගෙන ගන්න වේවි නෙත්නම් sry ටමා :eek:

මේ symbols වලින් ටමා අපිට පරිපථයට ඕන වෙන Items අඳුරගන්න පුළුවන් වෙන්නේ

Transistor

Capacitors

LED

Resister

Batteries

දැන් ඉතින් අපි Circuit හදද්දී දන ගන්න ඕනේ මුලික symbols දැනගත්ත නේ දැන් ඉතින් පොඩි simple cirucuit එකක් කියල දෙන්නම්

Simple LED flasher circuits

By simple, I mean that these circuits only flash one or two LEDs. This is opposed to the light chaser circuits that can flash four or more. Of course, the simplest LED flasher is simply to use a flashing LED. The problem with that approach is you have no control over the flash rate, but it does have its use for eye catching displays for selling stuff. The circuits below give you that control, plus they can flash two LEDs alternately.
There are many possible applications for the circuits below, especially for kids, who love flashing lights. Here's some possible uses.

Railroad crossing signal for model railroads.
Safety blinkers for bicycles, etc.
Fun stuff for Halloween, like making those plastic Jack-O-lanterns blink (try using ultraviolet LEDs here).
Christmas decorations.
Blinkers to locate items in the dark.

Transistor LED flasher

This circuit has a lot going for it. For one thing, it only consists of two transistors, two capacitors and four resistors. That also means it consumes very little power. You can control the flash rate by changing the size of the 100k resistors (100k makes for a pretty slow rate). You can also control the duty cycle by using resistors of different values on the two sides. The 470 ohm resistors control the current through the LEDs. Normally you want to limit this to 20mA, but to conserve battery power, you may need to limit it even further. You can also connect several LEDs in series, instead of using only one for each side. With red LEDs (1 per side) and the values shown, the circuit draws about 11mA. Here's what the actual circuit looks like:

On this circuit, the green wires connect to the LEDs, but you can mount them on the actual circuit board for some applications. The picture is about twice actual size. Here is an example of the use of this circuit:

+ Rep +

udarapath · Sep 29, 2011

අඳුරු වැටුනම පත්තු වෙන Light එකක්

A Simple and Cheap Dark-Detecting LED Circuit

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." (Circuit Example 1, Example 2.) 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 tricks 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.) for some op-amp based photodetector circuits with LED output, and check out some of the
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.

areyoucrazy · Sep 29, 2011

Ela kiri

matath igena ganna oni karala thiyena deyak

theekshana777 · Sep 29, 2011

maxx keep it up

udarapath · Sep 29, 2011

thnxx ppl tawa circuit tikak dennada hadanna

wisal · Sep 29, 2011

එල මචං කරගෙන යමු....

udarapath · Sep 29, 2011

thnxx mcn

Nalindax · Sep 29, 2011

niyamai.. +++

Dulanzz · Sep 29, 2011

patta patta machan ela math aasai owata

Rex921 · Sep 29, 2011

nice post.. but this transistor coding system is not using in sri Lanka..
2n3904 is D400 I think...as ZTX300 is C828....

udarapath · Sep 29, 2011

Dulanzz said:
patta patta machan ela math aasai owata

mamath

Rex921 said:
nice post.. but this transistor coding system is not using in sri Lanka..
2n3904 is D400 I think...as ZTX300 is C828....

yah mcn ur correcy

m2chamara · Sep 29, 2011

patta

udarapath · Sep 29, 2011

Electronic Dice

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Press the push switch to 'throw' the dice: this makes the circuit rapidly cycle through the dice numbers so that an effectively random dice number is displayed by the LEDs when the push switch is released.
Drill seven 5mm holes in a dice pattern to mount the LEDs on a panel such as a plastic box lid or sheet of thin plywood. They should be a tight fit but a little glue can be applied from the underside if necessary.

The 555 astable circuit provides clock pulses at about 5kHz for the 4017 counter which has ten outputs (Q0 to Q9). Each output becomes high in turn as the clock pulses are received. Only six counts (Q0-Q5) are needed so Q6 is connected to reset. Appropriate outputs are combined with diodes to supply the LEDs: for example Q1, Q3 and Q5 are combined for LED A.
The dice sequence has been started at 2 so the ÷10 output can be used for LEDs B1 and B2, this saves diodes and simplifies the circuit. Pressing the push switch makes the disable input low so that counting occurs.

This project uses a 555 astable circuit to provide the clock pulses for the 4017 counter.
Parts Required

resistors: 330 ×3, 470, 10k ×3
capacitors: 0.01µF, 0.1µF
diodes: 1N4148 ×6
LEDs: red 5mm diameter ×7
555 timer IC, such as NE555
4017 counter IC
DIL sockets for ICs: 8-pin, 16-pin
on/off switch
push switch
battery clip for 9V PP3
stripboard: 20 rows × 22 holes

Stripboard Layout

Circuit diagram

udarapath · Sep 29, 2011

Traffic Light Project

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This project operates red, amber and green LEDs in the correct sequence for a single UK traffic light. The time taken for the complete red - red & amber - green - amber sequence can be varied from about 7s to about 2½ minutes by adjusting the 1M preset. Some amber LEDs emit light that is almost red so you may prefer to use a yellow LED.
The 555 astable circuit provides clock pulses for the 4017 counter which has ten outputs (Q0 to Q9). Each output becomes high in turn as the clock pulses are received. Appropriate outputs are combined with diodes to supply the amber and green LEDs. The red LED is connected to the ÷10 output which is high for the first 5 counts (Q0-Q4 high), this saves using 5 diodes for red and simplifies the circuit.

This project uses a 555 astable circuit to provide the clock pulses for the 4017 counter.
Parts Required

resistors: 470 ×3, 22k, 100k
capacitors: 0.1µF, 1µF 16V radial, 10µF 16V radial
diodes: 1N4148 ×6
LEDs: red, amber (or yellow), green
1M preset, horizontal
555 timer IC, such as NE555
4017 counter IC
DIL sockets for ICs: 8-pin, 16-pin
on/off switch
battery clip for 9V PP3
stripboard: 20 rows × 21 holes

Stripboard Layout

Circuit diagram

Kasunrock619 · Sep 29, 2011

ela ela

udarapath · Sep 29, 2011

thnxxxxx

Aktamge · Sep 29, 2011

ela Ela

udarapath · Sep 29, 2011

Nu1Dnk · Sep 29, 2011

ela ela..

chk99 · Sep 29, 2011

ela mchn
maxxa work
circuit hadana widihath sinhalen dammoth kastiyata terum ganna lesi wei
keep it up...!!!
+++

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