Reading a circuit diagram involves memorizing the basic schematic symbols for various components; understanding the significance of their values and referencing conventions; identifying the interconnections between components; and integrating functional blocks. If any part of the diagram is difficult to understand, datasheets of the most important components may provide adequate information for interpreting it.
The first step to reading circuit diagrams is to get familiar with the standardized symbols for different components, such as resistors, capacitors, diodes and transistors. For instance, a few zig-zag lines, with two terminals extending outward, represents a resistor. All integrated circuits have a generic symbol, a rectangle with labeled pins extending out of it, accompanied by a value that identifies the chip.
To read the circuit diagram, note each symbol in the schematic along with its associated name and value. The value of a component specifies its most important characteristic, while its name, usually a combination of one or two letters and a number, helps reference specific points in the diagram. Follow the nets, or conducting wires, represented as lines between component terminals.
A tiny dot, called a node, is placed at an the intersection of wires. The absence of a node at an intersection means that the associated wires are not connected. Sometimes, nets are tagged with names instead of being routed across the schematic. Assume that nets with the same name are connected, even when there is no visible wire connecting them. If an extensive schematic is divided into functional blocks, interpret it as an integrated whole connected by named nets.