Eletronics Crash Course

1. Introduction

Electrical systems that process smoothly varying electrical signals.
Major building blocks: resistors, capacitors, inductors, diodes, transistors, batteries and wires.

Major Electronic Parts
- Resistors: true hole component (soldered to board); the bigger, the more power it can dissipate. To check its resistence using a multimeter: select the ohms symbol Ω; if the meter is automatic, the units (k/M/etc) it will be chosen automatically.
- Capacitors: ceramic, electrolytic (polarized), tantalum (polarized); measured in Faraday (F).
- Inductor: a coil of wire.
Digital electronics are based on analog building blocks, but these have been encapsulated in chips (integrated circuits) and operate with only two states: high (on) and low (off).
Groove in chips usually mark the “front” or “start” of the chip - this is useful when counting the pins. Start by counting to the left of the notch.

Current: how many electrons are moving; measured in amperes (A).
Voltage: manifestation of the electric fields; measured in volts (V); it also represents a difference of electrical potential between two points.

Alternating Current (AC) and Direct Current (DC) are the two main types of electrical flow.
Direct Current: the electric charge flows constantly in a single, unidirectional path with a fixed polarity.
Alternating Current: the flow of electrons periodically reverses direction and changes magnitude continuously in a waveform (typically a sine wave).
- The voltage of a wall socket, for example, is not 120V, but the root mean square of the values from the wave (min and max).

V = I * R, where:
- V is voltage in volts
- I is current in amperes
- R is resistance in ohms.
The instantaneous electrical power P delivered to a component is given by P(t) = I(t) ⋅ V(t), where:
- P(t) is the instantaneous power in watts (W).
- I(t) is current in amperes.
- V(t) is the potential difference in volts.