Schematic Reference

Here is a circuit that you can have fun with your friends. Especially you can catch your girl friend or your boy friend when ever they say lies. Circuit is very simple and you can build it with in few hours. But you will surprise with the results.
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For two electrodes you can use wires but to get best results use electrode pads which use in the hospitals. Attach the electrode pads to the back of the hand from one inch apart. Make sure meter should be zero before you start. If the person is lying the meter point will get move.

To operate the circuit it needs two voltages separately as shown in the diagram. You can use alkaline batteries for long use or two 4.5 V two power packs if you want.

This simple night lamp required very low current as 350mA. So you can operate this lamp using one normal 1.5V battery. But we recommend using alkaline batteries as you can operate long time without any headache.

When you buy a IC for this circuit make sure it is Cmos type. To get best results do not use an ordinary LED cheap bulb, use a good one. You can build this lamp without the photo resister but it will be then affect to the duration of the battery you can use, there for use photo resister to double the running time as mention in the diagram.

When daylight comes the photo resister will automatically disconnect the circuit and with the darkness it will be switched on again.

This is a simple circuit but we hope it will help you a lot and save your valuable time. You do not have to use millimeter to test a transistor if you build this circuit. You can have a 9 volts battery to operate the circuit. No matter if the transistor is NPN or PNP, if the transistor is shorted then no any LED should light. If the transistor is open Both the LED should light.

Now remember when you test a good PNP transistor then LED2 should light.
For NPN good transistor only LED1 should light.

Try to make the circuit on a PCB and put in a small box for its safety. Find a three pin socket and mounted it on the box. When you fix everything, only visible parts from the out side of the box should be the switch and three pins of the socket to test a transistor.  

This circuit will help you to save your electricity bill.  Incase if you leave the fridge door open more than twenty seconds. The circuit consumes very little current as it can operates by a 3 volts battery. You can enclose this whole circuit in a small box and keep inside the fridge.

R2 is a photo resistor. Normally photo resister has a low resistance but when you close the fridge door, with the darkness the photo resister’s resistance will go high. When you open the door fridge lamp will light and photo resister’s resistance goes down.

 Then the IC1 start its action. You can set the preset according to your wish but in this circuit it is set for 20 seconds delay. After 20 seconds the piezo starts beeps until you close the door.

Remember not to place the alarm box inside the freezer try to place it near the lamp.

This low distortion tone control circuit is used LM1036 IC to control the Bass, Treble, Balance and volume of any power amplifier. You can use this with Hi-Fi audio, car audio, TV audio systems. The specialty of this tone control circuit is you can supply 9V to 16V DC current. But never go to try more than 16 Volts.  Also it has a large range ( 75 dB ) of volume.

Output capacitors should be 10uf 25 Volts. If you want to add this to a stereo amplifier then you need to make one more tone control. To get best results use screen wires for controllers and inputs. Also try to use half watt resistors and when fixing capacitors make sure to consider the polarities.

This is another simple and easy to build amplifier. This circuit provides 22 watts and it is enough for
small audio systems. As this circuit requires 12 volts DC supply you can use this as a booster amp for
car speakers.  We recommend for you to use 4 ohms speaks to get best results. Although 8 ohms
speakers you can connect. Make sure you use good heat sink compound between the IC
and the heat sink .Try to use a fan to cool the hot heat sink if possible, otherwise we recommend to
have a big large heat sink.

For this small amplifier you can use our tone control circuit to control the bass, treble and the volume.
 For stereo systems you may need to make two circuits of this.

This is a circuit diagram of 60 Watts output class B power amplifier. The supply voltage is 48 Volts. We recommend not increasing the voltage if you want to run the amp long time. You can build this amplifier for low cost. The output transistors are 2N 3055 which are not expensive.

Circuit diagram shown a one amplifier means mono amp, if you want stereo amplifier which is 60W + 60W then you have to build two sets of this. Remember this is not for a beginner, you need to have some experience with electronic circuit diagrams and components before you start this project.

Nowadays LED are very popular. Some are using LED lights for homes instead of CFL as LED power consumption is really low. Now I am going to introduce you a torch with a single LED bulb which gives 90 times longer service than a normal bulb when you use AA alkaline batteries. Normally general torch bulbs consumes about 1.8 Watts while LED consumes about 25 mW . Can you believe this! But the brightness is same.

The below simple circuit is design for 6 Volts supply if you want to use 9 Volts then simply change the value of the R3 resistor in to 470 Ohms.

To get best results do not use a normal LED which are available in the market use the specific one.

We hope this circuit will help you to understand the action of a Battery charger. Lot of people has no idea how simple it is. In this circuit we have used two diodes, one capacitor and a transformer.  Ammeter is not necessary but it helps us to determine the charging level of the battery.

When you finish the circuit just connect the positive and negative wires to the battery terminals. Make sure to connect the positive wire to the positive terminal of the battery. When the charging is going on you can see 1 to three amps in the ammeter but when the charge is finish or the circuit is disconnected the reading should be zero.

We have used two diodes for full wave rectification and a capacitor is used for DC smoothing. Capacitor is not necessary but we recommend you to use the capacitor always.

The charging time will depend on the size of the transformer, means if we connect a big transformer that means battery gets a higher current ( more than 5A ). Incase if you want to use a higher current transformer use big diodes to pass the current accordingly.

We hope this circuit diagram will help you for your Christmas tree. This is not a difficult circuit but we do not recommend this for kids as it requires two voltages, 230 Volts and 9 Volts.  There are two ICs and one Diac do the major role in this circuits.

When you switch on the L1 bulb gradually increases its brightness. After it comes to the maximum brightness the bulb starts decrease the brightness gradually. This will never stop until you switch off the circuit as the cycle repeats.

You can change the brightness of the bulb by adjusting the VR1, but be careful when the circuit is connected to the live current. Make sure you use the same value and the ratings of the capacitor for the C3. Do not use low voltage of capacitor for it. The brightness of the bulb depends on the C3 capacitor’s charge and discharge.

This is another simple circuit. The whole circuit is mainly operated by four small transistors ( BC 548 x 4 ).  In this circuit diagram we have used twelve LED bulbs. You can use this dancing LED lights for many purpose. If you want you can adjust the dancing speed of the lights.

The supply voltage is 6 Volts as per our recommendation. But you can give up to 7 Volts. When fixing LED lights make sure to consider about the plus and negative sides.  Use different colours of LED lights and we sure you will be enjoyed the final results.

This is a good and simple circuit to flash one or more LED lights.  The circuit uses a NE 555 small IC. This IC is very common and easy to obtain from any electronic components shop.  As you can see in the circuit diagram we have used 10uF capacitor to control the flash speed of the LEDs. If you want to increase the speed simply put a higher value of a capacitor in place of 10uF.

Also you can increase the number of LED lights in parallel way. The maximum we recommend is 18 lights. Use PCB board to build this and supply six volts. Do not supply more than six as it can damage the your components as well as LED bulbs.

This is a five band graphic equalizer circuit. Comparatively this is a very simple diagram and working voltage is 8 volts. However you can supply up to 15 volts, but we do not recommend that much of supply. The specialty of this circuit is it operates by eighteen pins of a single chip IC ( BA 3812L ). The other components are very less.

The five frequency bands are 100Hz , 300Hz, 1kHz, 3kHz, 10kHz . You can use this simple equalizer with Hi Fi amplification systems as it provide low noise, wide dynamic range and very low distortion. If you want you can use two ICs of BA 3812L and make 10 band graphic equalizer.

This is a very simple game circuit. You can play this with your friends. To win this game one has to scores hundred points in very short time. Incase if you want to restart the game you need to press S1 button switch.

When supplies the output voltage make sure you do not use over 5 Volts as it can damage the components. We recommend you to use copper PCB board to build this circuit. Also we do not recommend any of our circuits for kids who do not familiar with electronics and live current.

As you can see in the circuit diagram the it operates by three ICs. Try to use good quality  switches for long durability.