The AND Gate is also known Logic gate this is a combinational Gate with 3 inputs and 1 output. This Logic gates work strictly by a defined truth table. the O/P is the side facing away while the other 3 sides are the inputs. And This gate is also called Northing Gate.
Logic symbol of AND Gate with two input
Component Required :
- Transistor (BC 547)
- Resistance (10K, 470 ohm)
- Momentary switch(2 pcs)
- Battery- 9v
- Dotted PCB
- Connecting wire
Before making this project we must have knowledge about the components which we will use in this Project so I will describe it one by one.
A transistor is a semiconductor device which is made by sandwiching two pn – type semiconductor. Transistor has three terminal collector, base and emitter. The transistor is use for the purpose of switching and amplification. There are two type of transistor, first is p-n-p and second one is n-p-n. in the AND Gate we are used n-p-n transistor.
This is a two terminal resistive device which is used to oppose the following the current in the circuit. Resistance is made up of carbon material. It never contain positive or negative terminal. We can use its any of the side as to oppose the current in appropriate manner. Resistance comes in different values which we used according to our need.
Led -LIGHT EMITTING DIODE
Led stands to light emitting diode. This is mostly use for lighting purpose or as a indicator of the circuit .this is a two terminal device Here in the image as you can see the long tail is positive and the short tail is negative.
Led Input voltage : 3 volt Dc.
So Now we got the essential information about the important components .
Working Principle of And Gate
In this logic transistor plays the important role to run this circuit. When we press switch (sw1) & switch (sw2) is low or sw1=0, sw2=5v or sw1=5v, sw2=0 both the transistor Q1 & Q2 are OFF. Transistor Q3 gates enough base drive from the supply trough R & so Q3 will be ON. Hence the output voltage x = Vcc is nearly equal to 0v. When we press both the switches (sw1 & sw2) together it provides +5v and both the transistor Q1 & Q2 will be ON & therefore, the voltage at, the collector of transistor Q1 will drop. So Q3 does not get enough base drive & therefore they remains OFF. Hence no current flow through the collector resistor of Q3 & therefore no voltage drop occurs across it. Hence output voltage, X=+5v. Finally the Led will glow.
Now I will describe you to make this project Step by Step.
First we need to collect all these components as you are seeing in the below picture.
Now as according to circuit diagram as in the picture insert all the components in the MDF sheet in same manner and do soldering with help of solder wire and soldering flux.
Now your circuit is ready. As You will give +9v to the positive terminal and ground to the negative terminal i.e emitter. Then press both the switch to glow the led.
So, Friends I hope you understand this project very well . In upcoming Tutorial I will be back with some new interesting Projects and we will discuss about some useful development topics. Here if you want to recommend that what I should write in upcoming Tutorial then please leave your comments. and if u need any help or query please don’t Hesitate to discuss with me. Thank You 🙂