My home made solar cell step by step

Step 1Materials you will need

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A sheet of copper flashing from the hardware store
A transparent CD case
Electric wire
Sodium bicarbonate or Table salt

An electric stove
hot glue
solder
Sheet metal shears for cutting the copper sheet

I suggest you visit http://scitoys.com there are many projects and interesting kit

Step 2How to prepare copper

The first step is to cut a piece of the copper sheeting that is about the size of the burner on the stove. Wash your hands so they don't have any grease or oil on them. Then wash the copper sheet with soap or cleanser to get any oil or grease off of it. Use the sandpaper or wire brush to thoroughly clean the copper sheeting, so that any sulphide or other light corrosion is removed.

Next, place the cleaned and dried copper sheet on the burner and turn the burner to its highest setting.

Step 3Cooking the copper

cook the copper for at least 30 min.
As the copper gets hotter, the colors are replaced with a black coating of cupric oxide. This is not the oxide we want, but it will flake off later, showing the reds, oranges, pinks, and purples of the cuprous oxide layer underneath.
The last bits of color disappear as the burner starts to glow red.
When the burner is glowing red-hot, the sheet of copper will be coated with a black cupric oxide coat. Let it cook for a half an hour, so the black coating will be thick. This is important, since a thick coating will flake off nicely, while a thin coat will stay stuck to the copper.
After the half hour of cooking, turn off the burner. Leave the hot copper on the burner to cool slowly. If you cool it too quickly, the black oxide will stay stuck to the copper.

Step 4Prepare the cooked copper

When the copper has cooled to room temperature (this takes about 20 minutes), most of the black oxide will be gone. A light scrubbing with your hands under running water will remove most of the small bits. Resist the temptation to remove all of the black spots by hard scrubbing or by flexing the soft copper. This might damage the delicate red cuprous oxide layer we need to make to solar cell work.
When you are finished cleaning the copper should be as in the photo

Step 5Assemble the cell

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Cut another sheet of copper ,
Solder a wire to each copper plate
glue to insulate the soldering
glue the plate as in photo

Step 6Fill and seal the cell

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seal the cell and fill it with a solution of baking soda (or cooking salt) and water

Step 7Test the cell

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test the cell whit Sunlight
A note about power

my cell produces 58 microamps at 0.10 volts.

Don't expect to light light bulbs or charge batteries with this device. It can be used as a light detector or light meter, but it would take acres of them to power your house.

 Make a solar cell in your kitchen

A solar cell is a device for converting energy from the sun into electricity. The high-efficiency solar cells you can buy at Radio Shack and other stores are made from highly processed silicon, and require huge factories, high temperatures, vacuum equipment, and lots of money.
If we are willing to sacrifice efficiency for the ability to make our own solar cells in the kitchen out of materials from the neighborhood hardware store, we can demonstrate a working solar cell in about an hour.
Our solar cell is made from cuprous oxide instead of silicon. Cuprous oxide is one of the first materials known to display the photoelectric effect, in which light causes electricity to flow in a material.
Thinking about how to explain the photoelectric effect is what led Albert Einstein to the Nobel prize for physics, and to the theory of relativity.

Materials you will need

The solar cell is made from these materials:

1. A sheet of copper flashing from the hardware store. This normally costs about $5.00 per square foot. We will need about half a square foot.
2. Two alligator clip leads.
3. A sensitive micro-ammeter that can read currents between 10 and 50 microamperes. Radio Shack sells small LCD multimeters that will do, but I used a small surplus meter with a needle.
4. An electric stove. My kitchen stove is gas, so I bought a small one-burner electric hotplate for about $25. The little 700 watt burners probably won't work -- mine is 1100 watts, so the burner gets red hot.
5. A large clear plastic bottle off of which you can cut the top. I used a 2 liter spring water bottle. A large mouth glass jar will also work.
6. Table salt. We will want a couple tablespoons of salt.
7. Tap water.
8. Sand paper or a wire brush on an electric drill.
9. Sheet metal shears for cutting the copper sheet.

How to build the solar cell

My burner looks like this:


The first step is to cut a piece of the copper sheeting that is about the size of the burner on the stove. Wash your hands so they don't have any grease or oil on them. Then wash the copper sheet with soap or cleanser to get any oil or grease off of it. Use the sandpaper or wire brush to thoroughly clean the copper sheeting, so that any sulphide or other light corrosion is removed.
Next, place the cleaned and dried copper sheet on the burner and turn the burner to its highest setting.



As the copper starts to heat up, you will see beautiful oxidation patterns begin to form. Oranges, purples, and reds will cover the copper.



As the copper gets hotter, the colors are replaced with a black coating of cupric oxide. This is not the oxide we want, but it will flake off later, showing the reds, oranges, pinks, and purples of the cuprous oxide layer underneath.



The last bits of color disappear as the burner starts to glow red.



When the burner is glowing red-hot, the sheet of copper will be coated with a black cupric oxide coat. Let it cook for a half an hour, so the black coating will be thick. This is important, since a thick coating will flake off nicely, while a thin coat will stay stuck to the copper.



After the half hour of cooking, turn off the burner. Leave the hot copper on the burner to cool slowly. If you cool it too quickly, the black oxide will stay stuck to the copper.



As the copper cools, it shrinks. The black cupric oxide also shrinks. But they shrink at different rates, which makes the black cupric oxide flake off.



The little black flakes pop off the copper with enough force to make them fly a few inches. This means a little more cleaning effort around the stove, but it is fun to watch.



When the copper has cooled to room temperature (this takes about 20 minutes), most of the black oxide will be gone. A light scrubbing with your hands under running water will remove most of the small bits. Resist the temptation to remove all of the black spots by hard scrubbing or by flexing the soft copper. This might damage the delicate red cuprous oxide layer we need to make to solar cell work.

The rest of the assembly is very simple and quick.
Cut another sheet of copper about the same size as the first one. Bend both pieces gently, so they will fit into the plastic bottle or jar without touching one another. The cuprous oxide coating that was facing up on the burner is usually the best side to face outwards in the jar, because it has the smoothest, cleanest surface.
Attach the two alligator clip leads, one to the new copper plate, and one to the cuprous oxide coated plate. Connect the lead from the clean copper plate to the positive terminal of the meter. Connect the lead from the cuprous oxide plate to the negative terminal of the meter.
Now mix a couple tablespoons of salt into some hot tap water. Stir the saltwater until all the salt is dissolved. Then carefully pour the saltwater into the jar, being careful not to get the clip leads wet. The saltwater should not completely cover the plates -- you should leave about an inch of plate above the water, so you can move the solar cell around without getting the clip leads wet.



The photo above shows the solar cell in my shadow as I took the picture. Notice that the meter is reading about 6 microamps of current.
The solar cell is a battery, even in the dark, and will usually show a few microamps of current.




The above photo shows the solar cell in the sunshine. Notice that the meter has jumped up to about 33 microamps of current. Sometimes it will go over 50 microamps, swinging the needle all the way over to the right.

How does it do that?

Cuprous oxide is a type of material called a semiconductor. A semiconductor is in between a conductor, where electricity can flow freely, and an insulator, where electrons are bound tightly to their atoms and do not flow freely.
In a semiconductor, there is a gap, called a bandgap between the electrons that are bound tightly to the atom, and the electrons that are farther from the atom, which can move freely and conduct electricity.
Electrons cannot stay inside the bandgap. An electron cannot gain just a little bit of energy and move away from the atom's nucleus into the bandgap. An electron must gain enough energy to move farther away from the nucleus, outside of the bandgap.
Similarly, an electron outside the bandgap cannot lose a little bit of energy and fall just a little bit closer to the nucleus. It must lose enough energy to fall past the bandgap into the area where electrons are allowed.
When sunlight hits the electrons in the cuprous oxide, some of the electrons gain enough energy from the sunlight to jump past the bandgap and become free to conduct electricity.
The free electrons move into the saltwater, then into the clean copper plate, into the wire, through the meter, and back to the cuprous oxide plate.
As the electrons move through the meter, they perform the work needed to move the needle. When a shadow falls on the solar cell, fewer electrons move through the meter, and the needle dips back down.

LED Chaser Using 555 timer + CD4017 counter

LED Chaser Using 555 timer + CD4017 counter

This is the schematic for a very basic 10 LED chaser I built. I prefer my "chasers" to run more slowly than most people and used a 10 uF capacitor for C1. The 10K pot can reduce the flash speed from not moving to whatever minimum time constant is possible with the C1 value you choose. Don't bother with ultra-bright LEDs for these "chaser" projects as cheaper, lower millicandela (mcd) LEDS work fine. I favor blue and green LEDS. The 4017 decade counter is a fabulous part and can be driven to flash a row of LEDs with a 555 timer chip or a discrete BJT multivibrator.

Dancing LED Circuit

Dancing LED Circuit

by om kumar gaurav

Here is a simple circuit which can be used for decoration purposes or as an indicator. Flashing or dancing speed of LEDs can be adjusted and various dancing patterns of lights can be formed.
The circuit consists of two astable multivibrators. One multivibrator is formed by transistors T1 and T2 while the other astable multivibrator is formed by T3 and T4. Duty cycle of each multivibrator can be varied by changing RC time constant. This can be done through potentiometers VR1 and VR2 to produce different dancing pattern of LEDs. Total cost of this circuit is of the order of Rs 30 only. Potentiometers can be replaced by light dependent resistors so that dancing of LEDs will depend upon the surrounding light intensity. The colour LEDs may be arranged as shown in the Figure

by om kumar gaurav

How to make Mp3 player at home

How to make Mp3 player at home

Posted by om kumar gaurav.

 

Published by www.ModemArea.com (Modem Unlocking Website). Aha, at last Now it is to make Usb Mp3 Player at home with Usb Mp3 Player Module. This Module can read MP3 files from a USB thumb drive and play it for you. I Found a compact sized USB Reader circuit, which has a Sleek IR remote control, Comes with small LED Based Display.(LED Based Seven Segment Display). I bought it from a local store in Bhiwani Haryana. I also purchased a IR receiver which was Damn cheap and you can control the played audio. IR module has points as "IR" , "Gnd", "5V" when using from Left to right. There is no need for connection other buttons and wires if u use IR sensor because after that u can do everything with module via Remote Control. The main attraction is its cost. The board cost only 120 Rupees ( 3$). Total cost f Equip so far. Rs.150/-

Requirement components and parts for create USB Mp3 Player at home

1. Usb Mp3 Module with Remote (See screenshot)

2. IR Sensor with Metal case (You can buy it from any TV spare parts shop)

3. 0-9 AC to Dc ( 1 Amp.) Transformer (You can buy it from any TV spare parts shop)

4. Audio Board 6 Volt to 9 Volt (You can buy it from any TV spare parts shop)

5. IC 7805 with 1000MFD 16 to 25 volt Capacitor (You can buy it from any Tv spare parts shop)*

* IC 7805 is used for convert 9 volt in 5 volt that is require for Usb Mp3 Module and your      audio board require 6 volt to 9 volt so there is no need to connect Your audio board to 5 volt supply only 5 Volt is only for Module circuit.

6. IN 4007 Diodes (4)   for filter 0-9 power supply

7. One blank project matrix PCB Board for mount IC 7805 Power Supply and other components   on it.

8. One USB socket for connect Pen Drive (Usb) to module

9. One Audio Jack with pin for connect speaker to you audio board

10. One Volume control (10 K) for control audio output

The board circuit diagram is so simple that there are a very few connections. Some of the connections are:-
Connector-1
3.3V - Power for IR sensor (Same as in Picture-3)
IR - IR data line of IR sensor
GND - Ground of IR sensor
PLAY - switch connection for play
VOL- - switch connection for vol -
PMCH - switch connection for mode(Radio/USB)
VOL+ - switch connection for vol +
R - Right channel output to audio amp
GND - ground
L - Left channel output to audio amp

Connector-2
GND - USB Ground
DP - USB DATA +
DM - USB DATA -
5V - USB 5V

Connector-3 (For SD card connection)
 If you have plan for use only Pen Drive for songs then there are no requirement for Connector-3. You can use your Memory Card using Memory card reader and insert it in USB port.
CS
DATA
CMD
CLK
DET
3.3V
The other main features are an built in FM receiver and you can also control FM with remote control User Friendly Auto Search & Save Station Operation Available. The player can read up to 1999 songs.

 

PRODUCT INFORMATION OF Vire (http://www.vire.net.cn) USB MP3 player board:
a) Play the FM channels
b) Display The Song Number
c) Numerical Key Input Operation for Song Selection.
D) FM Radio : 87.5 ¨C 108.0 MHz
E) Auto Radio Station Search Operation.
F) User Friendly Auto Search & Save Station Operation Available.
G) Numerical Display For Volume.
H) 188.8 LED Module Display.
k) Rotated Volume Control Key could be connected
i)   4/6 Keys On Product
ii)  Select Forward
iii) Select Backward
iv) Volume Up
v)  Volume Down

First you need 5 Volt and 9 Volt Power Supply. Here is complete diagram of IC 7805 5 Volt Power Supply for Usb Mp3 Module Circuit.

If you are using any external Amplifier or Computer Speaker then you can use 5 Volt Mobile charger as power supply for Usb Mp3 module. But be careful when connects charge pins make sure + and – pins have in right way otherwise board may be damage. 

Circuit Diagram for IC7805

Ready to use 7805 power supply for mp3 player

The +5 volt power supply is based on the commercial 7805 voltage regulator IC. This IC contains all the circuitry needed to accept any input voltage from 8 to 18 volts and produce a steady +5 volt output, accurate to within 5% (0.25 volt). It also contains current-limiting circuitry and thermal overload protection, so that the IC won't be damaged in case of excessive load current; it will reduce its output voltage instead.
The 1000µf electrolytic capacitor serves as a "reservoir" which maintains a reasonable input voltage to the 7805 throughout the entire cycle of the ac line voltage. The four rectifier diodes keep recharging the reservoir capacitor on alternate half-cycles of the line voltage, and the capacitor is quite capable of sustaining any reasonable load in between charging pulses.

   
Remote Control of Usb Mp3 Plyer circuit diagram Module 

 

The other main features are an built in FM receiver and you can also control FM with remote control. The player can read up to 1999 songs.

Audio Player Circuit Diagram for Mp3 Player

I suggest you must buy ready to use Audio board from any local store but i publish here audio circuit for your knowledge. It is very easy to understand and build.

All Components view

enjoy....

how to make solar mobile charger .

using this trick you can make mobile charger in your home............

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A little soldering is all it takes to make this cool little emergency cell phone charger. Keep it in the glove box of your car, in case you ever get stranded in the woods and start to hear banjo music!

You might be able to find the mini solar panels at a store that sells science or electronics equipment; otherwise you can order them online. Please note, you'll also be cutting the wire on the cell phone charger, so make sure it's not the only one you have! You can often find cheap chargers at discount stores like Big Lots -- it doesn't matter if it's AC or car compatible, since you'll only be using the end that plugs in your phone.

MATERIALS:

1 Altoids Tin case
2 Mini Solar Panels (3V 20mA each)
1 Solder (3")
1 Small Heat Shrink Tubing (4")
1 Large Heat Shrink Tubing (4")
1 Double Sided Tape (3")
1oz Flux
1 Solder Iron
1 Heat Gun
1 Wire Stripper
1 cell phone charger

Step1: Cut wires & tubing

Take the 2 solar power panels and cut all four wires to about 1" in length. Cut 1/4" of plastic off of the tip of each wire with the wire stripper so copper wires are exposed. This exposed wire is called a 'lead.' Cut the small heat shrink tubing into four equal pieces (1" each). Slide the small heat shrink tubing onto both black wires.

Step 2: Solder solar panel leads

Using a toothpick, paint leads with flux on a red wire from one solar panel, and a black wire from the other solar panel. Put those two leads together, and solder using your piece of solder and the soldering iron.

Step 3: Heat-shrink tubing

Slide small heat shrink tubing over the leads you just soldered together. Heat the tubing with heat gun just enough for it to shrink.

Step 4: Cut phone charger wire

Cut off the wire from your old charger to about 2.5 feet and strip off 2.5" of outer plastic from the loose end. Cut 1/4" off of each of the inside wires to make leads. Slide the full length of the large heat shrink tubing onto this main wire for later use in Step 6

Step 5: Flux, solder and heat-shrink loose leads

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On your main wire, slide a piece of small heat shrink tubing onto the red wire. Flux all loose leads of main wire as well as the solar panels with the toothpick. Solder red leads from main wire and solar panels together. Repeat with black wires. Slide heat shrink tubings over these soldered leads and use heat gun to shrink.

Step 6: Test charger

Test the charger by connecting it to a phone under bright light.

Step 7: Heat-shrink solar panel leads

On your main wire, slide large heat shrink tubing over the two soldered leads which connect to the solar panels. Use the heat gun to shrink the tubing.

Step 8: Tape and close

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On the back of the solar panels, cover the two brass rivets with double-sided tape (so they don't make contact with the Altoids tin.) Tape the two solar panels on the inside lid of the tin. Tuck the main wire into the case and close. Go somewhere sunny and charge it up!

thanks