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.





Note

# Be careful when you deal with 230v current.

#kids should not test this circuit.

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







Part list

0.47uF 250V Capacitor (C1) = 1

10K 1/4 W Resistor (R1, R2) = 2

1K 1/4W Resistor (R3) = 1

20V 1/4W Zener Diode (D1, D2) = 2

1N4148 Diode (D3) = 1

2N3904 NPN Transistor (Q1) substitute: 2N2222 =1

4N27 Opto Isolator (U1) =1

Solid State Or Regular Relay = 1


Note

# Use lower voltage zener for D1 and D2.

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.






Parts

Q1___________BC327 45V 800mA PNP Transistor

Q2___________BC337 45V 800mA NPN Transistor

C1_____________10nF 63V Polyester Capacitor

D1_________TIC106D 400V 5A SCR

D2-D5_______1N4007 1000V 1A Diodes

R1_____________Photo resistor (any type)

R2____________100K 1W Resistor

R3____________200K 1/2W Trimmer Cermet

R4,R7_________470R 1/4W Resistors

R5_____________12K 1/4W Resistor

R6______________1K 1/4W Resistor

SK1__________Female Mains socket

PL1__________Male Mains plug & cable

Note

# PL1 can be omitted and the input mains supply wires connected in parallel to any switch controlling lamps. In this case, if the switch is left open, the circuit will be able to drive the lamps; if the switch is closed, the lamps will illuminate and the circuit will be by-passed.

# When ths circuit operates don't touch the parts

# Due to 230 This is not suitable for kids.

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.




Note

# This circuit operates with 12V power supply

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.




# This circuit operates with Ac current so this circuit is not suitable for kids

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.




Note

# This circuit operates with 9V power supply
# pins 3,4,5,10,11,12 must be grounded.
# Use a heat sink or foil for IC LM 380
# This releases 2 watts power.
# All speakers should be 8ohm

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





Parts

R2 = 1M-1/2W
R1 = 470R-1/2W
D1 = 1N4007
D2 = 1N4007
D3 = 1N4007
D4 = 1N4007
D5 = 5mm. Blue LED
C1 = 220nF-275vAC


Note

# When you deal with 230V be careful.If you are too little Don't try this circuit

#Use Quality parts.Specially think about the W of your parts

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.




Note

# Design this circuit on a PCB
# use 9V to power this circuit

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.




Note

# Don't give power without an antenna
# For L1 make 3 turns of 1mm enamelled copper wire on a 10mm diameter plastic former. On the same core make 2 turns of 1 mm enamelled copper wire close to L3 and that will be L2.
# by using R9 the gain can be controlled
# Inductor L3 can be a VK220J type RFC.
# This circuit operates with 9V to 18V ( Dont pass 24V)

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.




Note

# This is 120V Circuit

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.




Note

# This circuit operates with 9V

# Use 8ohm speaker for this

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.




Note

# be careful when you deal with 230v current
# Always get the assistance of an elder.
# Don't pass 100W Then it will burn your circuit.