Full Adder Circuit – How it Works

A Full Adder is a digital circuit that performs the addition of three binary inputs. In this tutorial, you will learn how this circuit works, its truth table, and how to implement one using logic gates.

Schematic for a Full Adder Circuit
A Full Adder Circuit

What is a Full Adder?

Adders can either be Half Adders or Full Adders. The difference is that the Half Adder is used to add only two 1-bit binary numbers, therefore its sum can only range from 0 to 2. To improve this performance, the Full Adder was developed. It is able to add three 1-bit binary numbers, achieving a sum range from 0 to 3, which can be expressed with two output bits (“11”). 

The S-R Latch (Quickstart Tutorial)

The S-R latch is a key circuit in digital storage units. In this tutorial, you will learn how it works, its truth table, and how to build one with different logic gates.

S-R Latch Symbol
S-R Latch Symbol

What is an S-R Latch?

Before starting with the S-R latch you need to know what a latch is. A latch is an asynchronous circuit (it doesn’t require a clock signal to work), and it has two stable states, HIGH (“1”) and LOW (“0”), that can be used for storing binary data. Many sequential circuits and larger storage devices, such as shift registers, use latches as their principal building block.

The Useless Halloween Machine

This year’s Halloween project is a useless machine built with 555 timers. It’s a coffin with a switch. When you flip it off, a dark force rises from the coffin and flips it back on.

Controlling a Servo with 555 Timers

The idea for this project came after we published the simple 555 PWM circuit that controls a DC motor using a PWM signal created by a 555 Timer. I started thinking about the idea of controlling a servo instead.

After some experimentation, I realized that the frequency changed too much when I changed the duty cycle. So my servo would only move at random times.

Half Adder Circuit – How it Works

A Half Adder is a digital circuit that adds binary numbers. In this tutorial, you will learn how it works, its truth table, and how to implement one using logic gates. 

Half Adder Circuit
A Half Adder Circuit

What is a Half Adder?

A Half Adder is a digital circuit that carries out the addition of binary numbers. It’s the simplest of digital adders and you can build one using only two logic gates; an XOR gate and an AND gate.

How to adjust the brightness of an LED

Do you want to adjust the brightness of your Light-Emitting Diode (LED)? If we break it down to the most basic, there are two ways to change the brightness of an LED:

  • Changing the resistance value.
  • Turning it on and off fast (Using PWM).

Below I’ll explain the two options and show you circuits you can build.

Arduino Shield Project LED matrix

How to Build a Touch Sensor Circuit

In this project, you will build a touch sensor circuit. It’s a cool and simple circuit that allows you to control an LED with the touch of a finger. And you only need three components, how cool right? You can build this circuit if you’re a total beginner. The Touch Sensor Circuit Diagram You only

Voltage Divider Tutorial For Beginners

A voltage divider is a circuit that creates a smaller voltage from an input voltage by using two resistors. You’ll see it in both simple and advanced circuits all the time. Here’s the basic setup:

The basic voltage divider circuit

It is useful for example for reading sensors like thermistors and photoresistors since it converts an unknown resistance into a voltage. Or to reduce the volume of an audio signal via a potentiometer.

You can find the output voltage by inserting the resistor values and the input voltage into the following formula:

V_{OUT} = \frac{R2}{R1+R2} \cdot V_{IN}

Or you can use the calculator a little bit further down on this page.

Once you know how it works, it’s much easier to see how circuits work. And it will let you calculate voltages at many different points in a circuit – which is often needed to understand it.

NOT Gate (Inverter) – Logic Gates Tutorial

A NOT gate (or inverter) is a logic gate where the output is the opposite of the input. So you can say that the output is NOT the same as the input. It’s often called an inverter since it inverts the input. The schematic symbol for an inverter is like a buffer, just with a

NOR Gate – Logic Gates Tutorial

A NOR gate is a logic gate where the output goes HIGH (or “1”) only if all its inputs are LOW (or “0”). The schematic symbol for a NOR gate is like the OR gate, just with a circle at the output to indicate that it’s an inverted version of OR. “NOR” stands for NOT-OR

OR Gate – Logic Gates Tutorial

An OR gate is a logic gate where the output goes HIGH (or “1”) if any of its inputs are HIGH. So if A OR B is HIGH, the output Q also becomes HIGH. If A or B is true, then Q is true Truth Table OR gates can have more than two inputs. But

NAND Gate – Logic Gates Tutorial

A NAND gate is a logic gate where the output goes LOW (or “0”) only if all its inputs are HIGH (or “1”). The schematic symbol for a NAND gate is like the AND gate, just with a circle at the output to indicate that it’s an inverted version of AND. “NAND” stands for NOT-AND

AND Gate – Logic Gates Tutorial

An AND gate is a logic gate where the output goes HIGH (or “1”) only if all its inputs are HIGH. So if the inputs A AND B are HIGH, the output Q will also be HIGH. If A and B are true, then Q is true Truth Table AND gates can have more than

XOR Gate – Logic Gates Tutorial

The XOR gate is a logic gate where the output goes HIGH (or “1”) if one – and only one – of its inputs are HIGH. XOR stands for Exclusive-OR. Check out its symbol and truth table below. If A and B are different from each other, then Q is true Truth Table XOR gates

XNOR Gate – Logic Gates Tutorial

An XNOR gate is a logic gate where the output goes HIGH (or “1”) only if both its inputs are equal. So if the inputs A and B are both HIGH or both LOW, the output Q will be HIGH. If A and B are the same, then Q is true Truth Table XNOR gates

Logic Gates: The Beginner’s Guide to How They Work

Logic gates are the basic building blocks of digital electronics. These are the components that we use for “doing stuff” with the 1s and 0s. You can combine them to create other building blocks like latches, flip-flops, adders, shift registers, and more. The basic logic gates are AND, NAND, OR, NOR, XOR, XNOR, and NOT.