NPN and PNP Transistor

lots of kids ask me about the difference of NPN & PNP.So I think this will be so useful for you.

Simple game for kids

This is simple game for kids.You can propose your Friends to bring this ring one end to another end.while your friends are bringing this ring one end to another end if it touch the coil the bulb will light up.Then he loses the game.the chance goes to another.If one could take the ring to another side that one can win this game.this method is so impotent to check you nerves.if you can do this patiently you have good health condition

How to fix a tube light simply

This post shows how to fix a tube light with its parts correctly.lots of people asked me about this that is why I thought to give you some thing like this.now I think you will be able to solve your problems.

Ringing Phone ditector Circuit

Here I have introduced a ringing phone detector circuit.When people work in crowed areas they can't here when the phone is ringing.So this circuit will be useful circuit for you all

Security system for doors

This is a security circuit diagram.If someone cross the LED beem.The circuit will be activated.Here I have used red LED insted of the LED you can use Lazer beem too.You can connect a light or 230V alarm for this circuit.but dont pass 500W.If you want more bulbs you can attach them parallely.

water tank Alarm to stop over flowing

This circuit is so simple concept.But by using this circuit you can prevent overflowing your water tank.After water touching sensors the circuit will give a sound.then you can switch off the mot er.




Note

# fix your circuit near by the water tank.Unless it will not work properly due to less power supply.

# This circuit operates with 9V power supply

Door alarm circuit Diagram

This is a door alarm circuit.I have used a magnetic-reed switch for this.When the door opens the buzzer will give a beep beep sound.Changing R2 and C2 The period of generating beep sound can be changed.According to the values of this circuit you can get that sound for 4 or 5 seconds.double the value the you can double the time.





Note

# this circuit operate with 9V battry.

#Build this circuit on a PCB

Power on time delay circuit

This circuit is time delay circuit to power on.Most of electrical equipments burn due to power failures so this circuit is a best answer for that.

Variable Voltage Regulator Circuit Diagram(LM317T)

This is a voltage regulator circuit.This circuit can release 1.2V to 13.6V.and this supplies 1.2 amp.Changing the R1 and R2 you can change the out put value of the voltage.

Mettle Detector circuit Diagram

This is a mettle detector circuit diagram.We have used Ic4093 for this circuit.This circuit needs a a Faraday shield, which is connected to 0V.To make this one wrap a tin foil around the coil.and connect to 0v.Then you can use this circuit for find metal.Tune your mw radio until whistle sound comes.




Note
# This circuit operates with 12V power supply
# IC1d pin 11 needs to be attached to a MW radio aerial, or should be wrapped around the radio
# The prototype used 50 turns of 22 awg/30 swg (0.315 mm) enamelled copper wire, wound on a 4.7"/120 mm former. This was then wrapped in insulation tape.

Simple Tone generator Circuit

This is simple tone generator circuit.You can use this one for your alarm circuits,bugler alarms etc.Here I have used Common Ic NE 555.you can use this for various things Try to make new thing.

Simple Intercom Circuit

This is simple intercom circuit.Here I have used common Ic LM380.Now the switch is in the talk position for the speaker on the left,And the other persons position is listening position.If other one wants to speak The switch must be change to another position.(Both users should do that).Pins 3,4,5,10,11,12 are grounded.

Car Burglar Alarm Circuit

This is a burglar alarm for cars.If some one opened the car door.The alarm will activate.Normally this circuit provides 5 second to open the door and close it but If somebody opened it more than that the alarm will activate.To turn the circuit on S1 should be closed.If you want to open the door more than 5 seconds.You can deactivate the alarm by using S2.Exit delay time can be adjusted by using R1 and C1.




Note

# This circuit operates with 9v power supply
# Be careful when you work with high amp batteries

Touch Alarm circuit

This is touch alarm circuit.Here I have used very common Ic NE555 And common parts.Then easily you can make your circuit.You can attach this circuit for your door lock or for any other metal part.If some one touched that metal part the alarm will start to ring.You can use this circuit as a security circuit.Even you can attach this circuit for your fence.





Parts

# Transistor 2N3904
# Diode 1N4004
# IC LM555
# Relay
# Resistor 56 K
# Resistor 100 K
# Resistor 10 M
# Resistor 220 K
# Capacitor 47 uF at 16 V
# Capacitor 33 uF at 16 V
# Potentiometer 100 K

Note

# This circuit operates with 6V battery
#Connect touch pad to the metal plate of your main door or fence

230V LED Indicator circuit

This is very useful circuit for you.You can use this circuit as a current indicator.The special thing of this circuit is this circuit operates 110V to 230V.I myself have use this circuit for my door bell.so visitors who come home at night can easily see the door bell.you your self think different way and do something newly

Battery Charger Indicator Circuit

Most of you asked about a Battery Charger Indicator Circuit.This circuit indicates weather battery is charged or not.This circuit avoid the over charge of batteries purple LED will indicate the battery is charging.After charging purple LED is off.

Electronic Siren Circuit Diagram

Tis is a circuit of a siren.I suppose this would be very usefull circuit for you all.This circuit operates with 9V power supply

powerful pocket Headphone Amplifier circuit Diagram

Lots of guys asked me about Pocket head phone amplifiers.This circuit will be a good answer for that.Here I have used very common IC OPA134.You can power this circuit with 9V battery.

2Km Fm Transmitter circuit Diagram

This is a powerful transmitter so first of all I would like to tell you not to use this for illeagl things.You can transmitt signals from 2km.Use a matching antenna for this.

AC120V LED series Circuit

This is Christmas season so I thought to give a circuit to decorate your christmas tree or crib.By using this circuit you can light up 25 LEDs.The importent thing of thios circuit is this circuit doesn't want a transformer.Use 3.8 kilo-ohms 5w resistor.

DC Power Supply Circuit

This is a power supply circuit.This circuit converts AC 230V to DC 16V.So this is so useful circuit for you.Use quality parts for this specially Condensers.As the transformer use 12V transformer.

Simple Audio Amp Circuit

This is an audio amplifier circuit.Here we have used femous Ic 741 as the pre amplifier.Ic 386 acts here as the Power amp.R3 resistor controls the volume.R2 contralls the gain.

120V AC powered LED

Lots of you asked about a circuit which can light up a LED with129V AC current.So this is it.This circuit can light up a Led.If You want to light up two LEDs I have design a circuit for it.Actually you can attach This circuit for your door bell To see it for the people in the dark.And also you can use this as an AC power Indicator.

Water Level Ditector Circuit

This is very useful circuit for us.Because by using this circuit you can control your water pump automatically.When the water goes down the trigger sensor level.The mot er will start automatically.After passing the threshold sensor level the mot er Will stop automatically.









Note

# When you fix sensors fix them tiddly.If not They will short together.
#This circuit works with 12V power supply.

230v Lamp Flasher Circuit

This is 230V lamp flasher circuit.Here the bulb or bulbs flash regularly.You can control the speed of bulbs by adjesing the VR1.You can use more bulbes but dont pass the 100W.That means If you use 25W bulbs you can use only 4 bulbs But If you used 5W bulbs you can use 20 bulbs.

LED Flasher For the Christmas With NE555

I know now you are getting ready for your christmas.So I thought to give you a useful circuit.This is a LED flasher circuit .You can use this to decorate your christmas star or your crib.I have used here NE555 commen IC.this circuit works with 9v power supply.

Burglar Alarm Circuit

This is so impotent circuit for you.These days we can see robberies are increasing day by day so I design this to stop them.Here I have used thin copper wire If someone disconnected it, the alarm will start to ring.So use this to prevent robberies.



Note

# Use 5v To 15v power supply for this
#Use SWG 36 or higher

Power Amplifier with 2N3055

This is a powerful power supplier.The important thing of this circuit is,We have used common transistor 2N3055.This circuit works with 50v.The maximal input voltage is around 0.8 - 1V.This out put power is about 60w.

How to make a simple Speaker

Today I'm going to tell you how to make a simple speaker.First of all you need a plastic cup,a Magnet,coil.Then turn coil around the magnet turn about 40 turns.Then after fix the magnet middle of the plastic cup.finally connect the wires to the out put of your radio set then you can listen the sound.





Note

# Before you switching on the radio check whether volume controller is in low position or not.Because If not the coil will be burnt.

Police siren

This circuit generate the sound of American police siren.We have used famous NE 555 IC for this.you can operate this circuit with DC 12v power.

How to make an electric magnet

This is for kids


This is so simple thing.you need following things first

1 A nail
2 A coil
3A battery
4A switch




Then turn the coil around the nail but before turning the coil cover the nail with a peace of paper.Then attach every thing according to the following circuit.finally give the power and close it to the metal dust then you can see they stick to the nail..




# Now you know how to make an electric magnet

# As your second project make an electric bell

FM Transmitter Bug

This is a FM transmitter circuit.the spacial thing of this circuit is, this circuit can be fixed in a small space.The coil is four turns of 18swg wire wound around a quarter inch former.After turning one and a half turns from the supply end tap and fix the aerial.



Note

# This circuit is not legal one so don't miss use this.Though you did like that we can't get the responsibility of it.

# This circuit can be operated with 9V power supply.

Bicycle back Safety Light (IC 555)

Lots of road accidents happen as a result of not having back lights specially bicycle riders have to face this so I decided to introduce a new circuit.By using this circuit you can give a attraction to your bicycle too.This circuit can be operated with 3V...try this





Parts:

IC1,IC2________7555 or TS555CN CMos Timer IC

C1______________1µF 63V Polyester Capacitor

C2_____________10nF 63V Polyester Capacitor

C3____________100µF 25V Electrolytic Capacitor

R1_____________10K 1/4W Resistor

R2,R9,R10_____100K 1/4W Resistors

R3-R8,R11-R16__10R 1/4W Resistors

R17___________150R 1/4W Resistor

D1-D13_____Red LEDs 5mm. or bigger, high efficiency

SW1____________SPST Slider Switch

B1_______________3V Battery