55W Light From Bleach Powder and Water

Water and bleach in bottle of coke was fitted on the roof. It absorbs light at day time and reflects sunlight at night and is equal to 55 watt.

Fm Transmitter Hunt aka Fox Hunt

      Fox hunt aka fm transmitter hunt is game where the mission is to find the fm transmitters which hidden from the players. The principle used here is the fm transmitters are hidden and they will transmit a melody continuously. The players are provided with fm receivers consisting of Directional ( yagi uda) antennas. By using these directional antennas the locations of the hidden transmitters can be found. There will be more than 4 or 5 transmitters, those who found the maximum number of transmitters will win the competition.

Transmitter section

Description

Here is a simple melody generator circuit you can make using an IC, it is combined with a fm modulator.The  UM66 series are CMOS IC’s  designed for using in calling bell, phone and toys. It has a built in ROM programmed for playing music. The device has very low power consumption.Thanks for the CMOS technology.The melody will be available at pin3 of UM66 and here it is amplified by using Q1 to drive the speaker.Resistor R1 limits the base current of Q1 within the safe values.Capacitor C1 is meant for noise suppression.

       Circuit showing a fm transmitter.Here i have used a bc494 high frequency transistor for making this circuit .The fm modulator is changing the frequency of carrier signal according to the strength of information signal


Component Required

1. Resistor   :39k.100R
2. Capacitor  :10MF,2.2PF,4.7PF-2,102PF,103PF, 0.1uf,
3. Transistor: BC 494, HE8050S
4. Inductor :22nH
5. IC : um66

 Receiver Section

 

Description

                  Circuit showing a fm radio receiver .Here i have used ic cxa1619bs for making this circuit.Construct this circuit on a good pcb and give me your comment. The yagi uda antenna will provide high directivity.Part list and applications are showing below


Part List

Component No:    Value    Usage
R1    220R    Noise Reduction
R2    150R    Crystal Grounding
R3    330R  
R4    330R  
R5    330R,1/2 W      Current Limiting
C1    22pF    Oscillation
C2    22pF    Oscillation
C3    22pF    Oscillation
C4    203pF  
C5    102pF  
C6    4.7MF    Noise Grounding
C7    47pF    Feedback
C8    203pF    Noise Grounding
C9    100MF    Decoupling
C10    4.7pF    Voice Noise Grounding
C11    104pF    Audio Coupling
L1    22nH,3T    Oscillation
L2    22nH,4T    Oscillation
L3    22nH,5T    Oscillation
X1    4.7MHz    IF Frequency Generator
X2    2.7MHz    Mixer Frequency Generator
VC1    27pF Gang    Tuning
U1    CXA1619BS     Main IC

Antenna Design

 FOX HUNT competition in our college

Mobile Phone Jammer

Description

                 An fm transistor is used here for making a mobile phone jammer.Mobile phones are working in 450  MHz  frequency .Here the transmitter generate almost equal to 450 MHz  frequency there for the mobile phone does not identify the original signal but the signal range is very week so this circuit working in only 100 m range .This circuit working in only 450 Mhz .The power supply should not exceed 3Volt

Part List


Component No:     Value      Usage
R1     100R      Emitter loading
R2     39k       Base Biasing
C1    15 pf      Frequency
 Generating
C2    4.7pf      Feedback
C3     4.7pf      Feedback
C4    102pf      Noise Reduce
C5     1MF    Coupling
C6     2.2pf      Coupling
C7        103pf        Decoupling
Q1     BF 494      Amplification
L1     22nH     Frequency
 Generating

Wireless Mic

Introduction

Here i have designed a circuit for making a wireless mic set. The mic is actually an FM modulator. The speaker set should have an amplifier and it is attached to a Fm receiver circuit. Therefore the signals from the mic are frequency modulated and are transmitted to a wide range. Then the fm receiver circuit will receive these fm signals and are amplified by the amplifier in the speaker set.

Fm Transmitter section

Description

       Circuit showing a fm transmitter.Here i have used a bc494 high frequency transistor for making this circuit .The fm modulator is changing the frequency of carrier signal according to the strength of information signal


Component Required

1. Resistor     :  39k.100R
2. Capacitor : 10MF,2.2PF,4.7PF-2,102PF,103PF
3. Transistor : BC 494
4. Inductor : 22nH

Fm receiver section

Description

                  Circuit showing a fm radio receiver .Here i have used ic cxa1619bs for making this circuit.Construct this circuit on a good pcb and give me your comment.Part list and applications are showing below


Part List

Component No:    Value    Usage
R1    220R    Noise Reduction
R2    150R    Crystal Grounding
R3    330R   
R4    330R   
R5    330R,1/2 W      Current Limiting
C1    22pF    Oscillation
C2    22pF    Oscillation
C3    22pF    Oscillation
C4    203pF   
C5    102pF   
C6    4.7MF    Noise Grounding
C7    47pF    Feedback
C8    203pF    Noise Grounding
C9    100MF    Decoupling
C10    4.7pF    Voice Noise Grounding 
C11    104pF    Audio Coupling
L1    22nH,3T    Oscillation
L2    22nH,4T    Oscillation
L3    22nH,5T    Oscillation
X1    4.7MHz    IF Frequency Generator
X2    2.7MHz    Mixer Frequency Generator
VC1    27pF Gang    Tuning
U1    CXA1619BS     Main IC

Foldable n Stretchable Garden Fence

A Small Garden Fence Using Pipes. 

Construction of this item is simple but the measurements should be accurate.

 

Items Required

• Pipes of cross section 3/4 inches ( PVC, aluminum, plastic)
• Nuts and bolts of length 2 inches
• Pipe cutter and drilling machiene
• Scale and marker 

 

Construction

• make holes as marked in the first figure
• place two pipes diagonally and screw them at the centre
• make such 'X' shaped compinations
• combine 2 such 'X' shapes by screwing the ends as shown in the above figure

 

 

• There should be 2 pipes of bigger size in the end points for supporting the fence
• The fence is attached to the supports as shown in the figure
• One end of each support is left free and other is screwed, this is for folding and streching

 

 

 

• Finally it will look something like this
• This is sample so it contains only 3 'X' shaped cross sections
• Depending on the maximum area to be covered you can choose the number of X shapes

 

 

 

• When it is stretched it will  look like this
• You can adjust the size by stretching between maximum and minimum length.

 

 

Simple Emergency lamb using LED

If you are interested in making an emergency lamb of your own then you can follow these instructions.
First of all you will need these things
1.Soldering iron
2.Solder
3.Dot Board
4.Led (10- 20no:s)
5.Resistor(220ohm, 1 for each led)
6.Plastic Box
7.6v Rechargeable Battery
8.Switch
9.An adapter for charging Battery

CIRCUIT DIAGRAM 

 

 

 Make connections as shown in the figure.

Place the dot board on the flat surface of the plastic box and insert the battery into the box.

.
The switch can be left free or it can be attached to the box. Charge the battery according to the use. Normally it needs 2 hrs to charge completely. U can use this emergency up to 24hrs continuously