Digital Electronics

 

Digital Electronics

Digital electronics are electric circuits that work on only two fixed values: "1" and "0". They use a series of 1's and 0's to store and communicate information. They can also perform math using just 1's and 0's. This is called Boolean math or Boolean logic.

How do they get just 1's and 0's?

In most digital electronic circuits when the voltage of the circuit is positive and near the supply voltage it represents a 1. This is also called HIGH. When the voltage is close to the ground level (or zero), it represents a 0, which is also sometimes called LOW. With these two signals most anything can be stored and communicated including the picture on the screen you're looking at right now. But it takes a LOT of these signals running VERY fast!

What are electronic gates?

In digital electronics, gates are electrical functions that are performed on 1's and 0's. Sort of like simple math. One example of this is the AND gate. There are two inputs and one output to an AND gate. The output is only a 1 if both inputs are a 1. If either input is a 0, the output is a 0. An even simpler gate is the Inverter. In this case there is one input and one output. If a 1 is input, then a 0 is output. If a 0 is input then a 1 is output. It just Inverts the signal.

A logic AND gate with two inputs and one output

What are electronic chips?

Electronic chips are a whole bunch of electronic gates put into one small area. These chips can have millions and millions of gates in order to do all sorts of complex stuff. There are chips that do graphics for your computer screen, chips that have lots of memory for saving data, and chips that run programs like your computer's CPU. To make electronic chips, special materials called semiconductors are used together with expensive precision equipment. Hundreds of engineers may spend years just to design and invent one complex electronic chip.

Integrated Circuit computer chip called a CPU

Where are they used?

Digital electronics are used throughout the world including in computers, iPods, video games, televisions, cameras, cell phones, and cars. Although digital electronics are a relatively new invention in the world, most of us could hardly imagine a world without them.

Fun facts about Digital Electronics

• The main semiconductor used in electronic chips is silicon. Silicon is the most abundant element in the Earth's crust after oxygen.
• A lot of the internet information is sent over fiber optics. With fiber optics light is used instead of electricity to send the information.
• The first computer chip was invented by Jack Kilby while working for the company Texas Instruments.
• In 2011 Apple became the largest buyer of computer chips in the world because of the iPhone.

Electricity in Nature

 

Electricity in Nature

Electricity is not only found in power lines and electronics made by man, but is also found in nature. In fact electricity is all around us. We see it in lightning storms, animals use it as a defense, even our bodies use it to send messages to our muscles.

Lightning

One of the most fantastic displays of electricity in nature is lightning. Lightning occurs when large amounts of electrostatic energy builds up in clouds from the energy of storms. When electrically charged regions of clouds discharge their energy, a large flash of electricity can be seen in the sky. Lightning may occur from cloud to cloud or it can occur from cloud to the ground. Lightning strikes carry huge amounts of energy. A typical lightning strike carries an electric current of over 30,000 amps and delivers 500 megajoules of energy.

Lightning also creates a loud noise called thunder. This is because the air within lightning gets so hot, that it transforms into plasma for a short period of time. When the molecules of air turn from gas to plasma, their expansion causes a shockwave that we hear as thunder.

Animals

Some animals use electricity to survive in nature. Many of these animals are found in the ocean where some use electricity to detect objects around them (sort of like seeing) and others use electricity to fend off predators or even hunt for food.

One of the most famous of the electric animals is the electric eel. The electric eel can produce large amounts of electricity, enough to even kill a human or stun a large horse. The eels typically swim into a school of fish, discharge a large amount of electricity, and then dinner is served!

Another example of animals using electricity is electroreception. Many fish such as sharks, lampreys, and catfishes have the ability to generate electric fields and then use these fields to detect objects around them. This helps them to "see" in dark areas and to sense hidden prey.

Human Body

Not only can we see electricity at work in nature, we are constantly using electricity in our bodies. Every time we move a muscle, it's the result of an electrical signal being sent from our brain to our muscles telling them to move. We actually have a complex system of nerves throughout our bodies that use electric signals to control everything we do.

Static Electricity

Lightning isn't the only form of electrostatic energy we see in nature. Static electricity charges build up all around us. You probably have noticed static electricity when you went down a slide at the park and your hair stood up strait. The friction from the slide on your body caused a build up of charge that made your hair stand up. Sometimes you can even build up a charge on your body that will shock someone else when you touch them. This is static electricity.

The Earth

Deep inside the Earth huge electric currents are generated from the spin of the Earth's iron core. These electric currents in turn cause a magnetic field that extends well beyond the surface of the Earth and into outer space.

The Earth's magnetic field is important because it protects the Earth from the solar wind of the Sun. Without the protection of magnetic field, there would likely be no life on Earth. The magnetic field also enables the use of compasses to tell the direction.

Uses of electricity

 

Uses of electricity

We use electricity constantly in our daily lives. It is one of the most important types of power and energy that we use.

Electricity in our House

Electricity travels to our house over power lines from a big power plant somewhere far away. Your parents actually have to pay for how much electricity is used. There is an electric meter outside of your house that keeps track of this. The more the lights are on or the TV is running, the higher the bill will be from the electric company.

Once the power comes to our house, it gets sent out on wires to sockets in the walls. We can plug all sorts of things into these sockets and use the power from electricity. In our homes we power lights, air conditioning, televisions, ovens, and more from electricity. Without it, we'd be bored, hot, and sitting in the dark.

Batteries

Some electricity comes from batteries. Batteries use chemicals to store up electricity that can power devices like cell phones, radio controlled cars, handheld video games, and flashlights. Batteries run out of power after a while and either need to be recharged or recycled. Remember to always recycle your batteries as there are dangerous chemicals in them!

Other uses

Electricity is used in cars too. There is a big battery to help the engine get started. Then the engine generates electricity for the radio, lights, and other cool features. Some cars run 100% on electricity by using big batteries that get charged up from a wall socket.

Electricity also can make magnetism. This can be used to create giant powerful magnets as well as fast and quiet magnetic trains. Electric motors generate magnetism to turn the motor and cause movement for all sorts of uses.

History

One of the first great uses of electricity was for communication using Morse Code and the Telegraph in 1840. This allowed messages to be sent long distances in an instant. After that came the telephone and the radio and, in 1880, electric light. These inventions and the use of electricity changed the world. Electricity continued to change the world with new inventions such as the TV and, even more recently, the personal computer and the cell phone.

Fun facts about the Uses of Electricity

• 25% of the city of San Francisco's energy is generated by wind power.
• Electric eels use electricity to ward off enemies. They can produce a shock of around 500 volts.
• Our bodies use electricity to communicate including telling our heart to keep beating.
• Two famous scientists, Thomas Edison and Nikola Tesla, once had an argument over what kind of electricity we should use in our homes, AC or DC. Tesla won and AC is delivered to most homes still today.
• Electricity was first used in homes for lighting.