Basic Electrical

Definitions

What is Electricity?

When you plug in your coffee maker in the morning, you use electricity. When you watch tv you are using electricity. When you drive your electric car, you use electricity. When you are flying your drone, you are using electricity.

Electricity is the flow of electrical energy through some conductive material.

Code, Circuits, & Construction: code and fabrication resources for physical computing networking

http://www.tigoe.com/pcomp/code/circuits/understanding-electricity/

Electricity vs. Electronics

Electricity can occur by design (e.g., the power coming through your wall socket) or on accident (e.g., lightning hitting a tree).

Electronics refers to harnessing electrical properties to convey information or create an intended outcome.

Electricity Basics

When you are beginning to explore the wonderful world of electronics, it's vital to understand three core elements of electrical charge: Voltage (v), Current (i), and Resistance (r).

These three principles help us understand how and why electrons do what they do and thus how we can make them do what we want them to do.

Or more simply, when you understand these concepts, you're more likely to make cool projects and fry less electronics along the way.

Note: This image represents Ohm's law which is a useful formula for understanding the mathematical relationship between voltage and current.

Voltage

Voltage is a measure of the electrical energy of a circuit.

It is measured in Volts. In the water analogy, voltage would be the water pressure. Think of a geyser as high voltage, and the shower of a low-rent apartment on the fifth floor of a tenement building as low voltage (unless you’re one of those lucky people with good water pressure!).

Current

Current is a measure of the magnitude of the flow of electrons in a circuit. It is measured in Amperes, or Amps. The higher the amperage, the more electricity is flowing.

Battery current is called direct current (d.c.) because it flows constantly in one direction. The electricity that flows in your home is called alternating current, or a.c., because it flows backwards and forwards many times a second.

Resistance

Resistance is a measure of a material’s ability to oppose the flow of electricity. It is measured in Ohms. A kink in the pipe would act as a resistor, limiting the current (and the voltage) flowing through the pipe.

Circuits!

Circuit

A circuit is a closed loop containing a source of electrical energy (like a battery) and a load (like a light bulb). Every circuit has to have a load of some sort, All of the electrical energy in a circuit has to get used by the load. The load will convert the electrical energy to some other form of energy.

Every circuit has to have a load of some sort, All of the electrical energy in a circuit has to get used by the load. The load will convert the electrical energy to some other form of energy.

Closed Circuit

Electricity will flow through a copper wire if we connect it to a battery. If we add a light bulb, electricity passing through the light bulb turns into light.

Could you make a version of this diagram in your own aesthetic - like you did with the short circuit diagram (which is lovely!!)? Does not need to be a gif (unless you want to do that).

Open Circuit

An open circuit doesn’t have a complete path for electricity to flow which means that it's not functional. 

Same request here: Could you make a version of this diagram in your own aesthetic - like you did with the short circuit diagram?

Needs to have an opening for open circuit, replace with right image from slide 11

Short Circuit

This circuit is called a short circuit and it might lead to damaging the battery because there is nothing preventing electrons from moving very fast from the negative to the positive terminals.

Christiane, can you make a cuter version of this diagram and place it in the "short circuit" slide - one right after this one?

In a short circuit the electricity moves through the wires, but doesn't hit it's "load" such as a light/led.

Electronic Sensors

Electronic sensors convert some other form of energy (light, heat, sound pressure, etc.) into electrical energy so that we can interpret what’s going on electronically.

For example, a microphone changes sound pressure waves in the air to a changing electrical voltage. By amplifying and reading that electrical signal, we can interpret what the sound was that caused it. This process of changing one energy into another is called transduction, and devices that do it are called transducers.

Components

LEDs

LEDs are the workhorse of simple electronics projects. There is so much you can do with this simple, yet impactful electronic.

Here is what you need to know to get the most out of your LED projects:

1. LED stands for Light Emitting Diode.
2. LEDs are polarized, which means electricity can only flow through them in one direction. If your LED isn't lighting up, try flipping it around!
3. Too much electricity can burn an LED out. You'll probably need to use a resistor with one!

AMAZING

Conductors: Materials through which electrical current moves freely.

Insulators: Materials which prevent the flow of electricity.

Resistors resist, but do not totally block, the flow of electricity.



They are used to control the flow of current. Current can move either way through a resistor, so it doesn’t matter which way they’re connected in a circuit.

The colors on a resistor are a language to communicate the level of resistance they will add to your circuit. Look up a resistor calculator to help guide you in choosing the right resistor.

Resistor symbol

THESE ARE SO CUTE!!!!

There are many other types of components which you’ll come across:

Switches control the flow of current through a junction in a circuit.

Transistors and relays are switching devices.

Thermistors change resistance in reaction to varying temperature.

Photoresistors change resistance in reaction to varying light.

Flex sensors change resistance in reaction to being bent or flexed.

Piezoelectric devices create a varying voltage in reaction to slight changes in pressure.