As I’ve started learning physical computing, controlling lights, switches and connecting devices to networks, I’ve begun to learn electronics as a necessity. The following is a collection of notes from reading Getting Started In Electronics by Forest M, Mims III. I highly recommend the book with the addition of physically writing down your own notes to understand the material.
All matter has electrical properties. Matter is composed of units called atoms. Atoms contain different combinations of smaller particles called protons, neutrons, and electrons. Electronics is the study and application of electrons, their behaviour and their effects.
Inside the atom, electrons have a negative electrical charge and protons have a positive electrical charge. Nuetrons have no charge.
Usually an atom has equal parts protons to electrons. This makes the total electrical charge neutral. However, it is possible to dislodge electrons from atoms and thus cause an atom to have more protons than electrons. This is called a positive ion. It is also possible for an atom to have more electrons than protons. This is called a negative ion.
Positive ions attract free electrons. These traveling electrons are called an electrical current and the material through which electrons travel are called conductors. Materials through which electrons travel poorly or not at all are called insulators.
Current is the quantity of electrons traveling through a given point over 1 second. 1 ampere is equal to 6,280,000,000,000,000,000 electrons.
Voltage is the amount of electrical pressure. It can be thought of as the force that pulls electrons through a conductor.
Wattage or power is the actual work performed by the electrical current.
Conductors are materials that do not resist the flow of electrons. All conductors have some resistance and this is measured in Ohms.
Current can flow through a circuit in one continuos direction. This is called direct current (DC).
Current can also quickly and periodically switch directions. This is known as alternating current (AC).
A simple circuit can send representations of information using patterns of on and off. These are known as pulses and can represent complex information such as speech.
- A pulse is a quick increase or decrease in a current flow.
- A wave is a repeating flucuation in a current or a voltage.
- A signal is a periodic waveform that conveys information.
- Modulation is the process that generates a waveform.
- Noise is the small random electrical currents entering a circuit.
Next up will be a summary of electronic components, their effects and uses.