#3 How to Read the Schematic ET2008 Sistem Embedded

Schematics are our map to designing, building, and troubleshooting circuits. Understanding how to read and follow schematics is an important skill

Schematic Symbols Resistors

Potentiometers and Variable Resistors Three terminals Two terminals

Capacitors

Inductors

Switches single-pole/single-throw

Power Sources

Batteries

Voltage Nodes

Diodes

The most common, Zener diode is used as a voltage reference element Schottky diodes are useful in voltage clamping applications and prevention of transistor saturation Less energy is wasted as heat-> efficient choice for applications sensitive to efficiency -> they are used in stand-alone photovoltaic systems in order to prevent batteries from discharging through the solar panels at night as well as in grid-connected systems containing multiple strings connected in parallel Schottky diodes are also used as rectifiers in switched-mode power supplies. The most common, Zener diode is used as a voltage reference element

Transistors Bipolar Junction Transistors (BJTs) Collector Base Emitter

Metal Oxide Field-Effect Transistors (MOSFETs) Drain Source Gate MOSFET is voltage controlled (BJT is current controlled) MOSFET have a very high input impedance, so just about anything can drive them

Digital Logic Gates

Integrated Circuits

TTLs

Op Amps Inverting Non-inverting

Voltage Regulators

Miscellany Crystals and Resonators

Headers and Connectors

Motors, Transformers, Speakers, and Relays

PTC symbol is the generic symbol for a thermistor, a temperature-dependent resistor (notice the international resistor symbol in there?)

Name Designators and Values

Reading Schematics Nets, Nodes and Labels Junction and nodes

Net Names

Schematic Reading Tips Identify Blocks

Recognize Voltage Nodes

Reference Component Datasheets If there’s something on a schematic that just doesn’t make sense, try finding a datasheet for the most important component.